MK5 Golf GTI
All Things Mk5 => Mk5 General Area => Topic started by: Itguy on November 18, 2013, 09:25:12 pm
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Hi everyone
I seem to be having real problems with this.
I replaced my thermostat at the weekend with no effect on our slow warm up problem and today have replaced the ECT engine coolant temperature sensor with a genuine VAG 06A919501A.
The one I took out was the same part number but without the A on the end.
I've just been out and done 25 mins of driving (7c outside) and it didn't get to 90 on the gauge. It got to about 80 then went to 78 and back to 80 so I can only assume that's where it would settle. The old sensor did get to 90 and sit there (tested after I fitted the new thermostat so I am comparing apples with apples).
Does the new sensor need calibrating or something in VCDS? Something need resetting??
This is starting to drive me crazy. Surely it shouldn't take 20+ mins to warm up?
Did the plumbing change on the later engines after ours (ours is an 05).
Thanks
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Was the thermostat a genuine one..?
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Yep and tested in a pan of water with a thermometer before fitting
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Is the aircon switched off?
Is the aux coolant pump running?
Have we got an air lock - Is the system pressurising - extract from a post else where - no pressure means we can be stuck with an air lock!
The radiator cap actually increases the boiling point of your coolant by about 45 F (25 C). How does this simple cap do this? The same way a pressure cooker increases the boiling temperature of water. The cap is actually a pressure release valve, and on cars it is usually set to 15 psi. The boiling point of water increases when the water is placed under pressure.
When the fluid in the cooling system heats up, it expands, causing the pressure to build up. The cap is the only place where this pressure can escape, so the setting of the spring on the cap determines the maximum pressure in the cooling system. When the pressure reaches 15 psi, the pressure pushes the valve open, allowing coolant to escape from the cooling system. This coolant flows through the overflow tube into the bottom of the overflow tank. This arrangement keeps air out of the system. When the radiator cools back down, a vacuum is created in the cooling system that pulls open another spring loaded valve, sucking water back in from the bottom of the overflow tank to replace the water that was expelled.
All just thoughts
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VWs run a sealed system.
They're slightly different from the Hondas and what not which have rad caps and overflow tanks.. The Golf is a self-bleeding system. When I changed my coolant after you topped it back up it was fine.
aircon on/off wouldn't have anything to do with the temp unfortunately :(
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Them two fans running on the front with the aircon on is going to be cooling the system.
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I'm going to take it to work tomorrow for a longer run, but I suspect it will still be under reading.
How could this be with a new sensor compared to the old one??!
I presume then that there is nothing in VCDS which would help?
The aircon was off when we went for the drive (Econ mode on). Cabin temp was set to 22c and auto fan speed.
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No you can use VCDS and even the climatronic displays to display engine temperature but it will be the same as the dashboard display (within reason).
Either the thermostat is faulty or the CTS is faulty.
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You can check the temperatures in the system with VCDS and do logs but that's it as far as I'm aware.
I'm not sure if there's also a gauge sensor - would have to check it out.
What I would be checking is if those fans are running regardless of the switch position and look to see if that's aux pump is running with VCDS.
It may also be self venting but air lock would be high on my list!
Finally, checking on Google the year 2005 seems to be a cold car - plenty posts with this problem!
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Can't be the thermostat as I've tested it prior to fitting.
I know I can test the coolant sensor by using my multimeter and checking the resistance while warming up but is there a list anywhere that says what ohms should = what temp?
Must be a bit odd though having a faulty genuine one? Somehow I'd need to prove it to them for them to swap it at the TPS I bought it from though too?
I'll see what tomorrow brings but as the old one did eventually get to 90 it might be that I just refit that and be done with it, although I'm annoyed that this new one doesn't work correctly.
From reading other threads someone suggested that the type of coolant used may have an impact? It does have pink coolant in at the moment but I don't know if it's genuine VW or not. Someone said that VW put additives in to aid fast warmup?
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You do get new items faulty but it's rare.
You may need to check the sensor wiring physically?
Ignoring what the gauge says "does the cab get hot" that's what you need to know!
If it's hot then it's electrical display issue - put your own thermometer in the cab and check how hot it gets on full heat.
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Just my 2 cents but on our cars there are two coolant temp sensors!
One is below the intake manifold and I'm assuming this is the one you changed. The other is below the vacuum pump (battery side of head). Unclip it, clip looks like this
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fc1552172.r72.cf0.rackcdn.com%2F43947_x600.jpg&hash=026704cef03d4f1dcaf78cbab5e43e6a5109a4bf)
Pull it out, and put the new one in. There is an O ring (N90316802) on the sensor which ideally should also be replaced as well before putting the clip back.
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It's the one on the side of the engine that I swapped not the one underneath in the rad hose off the thermostat.
The cabin does get hot and heat starts to come out of the vents quite quickly. I'm sure the car is physically fine but I obviously want the temp sensor to be right so the fuelling is correct.
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I was suggesting you try changing the other sensor as well if you're convinced the thermostat is ok.
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Can't be the thermostat as I've tested it prior to fitting.
I know I can test the coolant sensor by using my multimeter and checking the resistance while warming up but is there a list anywhere that says what ohms should = what temp?
Must be a bit odd though having a faulty genuine one? Somehow I'd need to prove it to them for them to swap it at the TPS I bought it from though too?
I'll see what tomorrow brings but as the old one did eventually get to 90 it might be that I just refit that and be done with it, although I'm annoyed that this new one doesn't work correctly.
From reading other threads someone suggested that the type of coolant used may have an impact? It does have pink coolant in at the moment but I don't know if it's genuine VW or not. Someone said that VW put additives in to aid fast warmup?
Someone wrote it on the internet somewhere so must be true!
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My car takes around 7 miles to get to normal, not sure if this is normal but it does take longer than my old mk4
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Yes these engines can take a bit of time to warm up, it is normal. When it's colder outside it will be slower..
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If the coolant temp got up to 90 in a reasonable time with the new (tested) thermostat and the old temp sensor, and now the temp reads low/uneven with the new (untested) temp sensor - suggest you change the new sensor back to the old one and see what happens.
There must be a set of figures for temp/ohms resistance for a new sensor somewhere! Couldn't find one when I looked a few weeks back ...
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As above if your old sensor worked then pop it back in. I brought my first thermo from Euro car parts, and that didn't work, so i brought a gen one from VW and had no issues after fitting it.
Still sounds like a dodgy thermo tbh, as i had same issues before i changed mine. Maybe the TPS one works at a slightly different temp. My car takes around 10mins to heat up full, but then again i am in scotland at the mo and its bloody nippy.
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Ok - update.
I left the new temp sensor in today and after driving about 15 mins/15 miles earlier it did get to 90 on the gauge and stay there, so it is ok. Outside temp was 4.5c.
I'm coming to the conclusion that this is just a slow engine to warm up, I can't see anything else wrong.
Does anyone know/understand how the plumbing works on the AXX engine? I'm wondering if it's a problem with the thermostat bypass function for example?
How do I test / see if the aux coolant pump is running too (without VCDS which I don't have)?
Thanks
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Ok, another update.
Seems as though something still isn't right as tonight on the way home the temp went up to 75 and hovered there. I then sat in stationary traffic and it went up to 90 and sat there.
Moved off again and it settled back at 75 on the gauge.
It did this several times up and down depending on the traffic I was in.
It didn't do this before I fitted the new sensor so I'm suspecting it is under reading the temp and what I can see on the gauge is just normal fluctuations of temp going between 85 and 100 which would normally be shown by the gauge as 90. I've read somewhere that the gauge shows a small range of temps as 90 to stop the driver from worrying that things are wrong when it's minor fluctuations.
Having just got home I need to leave the car to cool down a bit before I can swap the old sensor back in to check the theory.
Obviously if it does the same with the old sensor in then it's the thermostat.
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That is PURE symptoms of a faulty thermostat. (heats up stationary and cools when driving).
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Or as you said the bypass thermostat or V50 pump.
I've emailed you some component drawings and operational temperatures which may help.
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Well it's -2c outside now so it will have to wait for another day when it's a bit warmer!
First step I think is to put the old temp sensor in and see what happens.
I did test the new thermostat as previously said, it didn't even start to open until 86c in my boiling pan of water. Unless it's failed straight after fitting?
Bypass thermostat? Is that somewhere else?
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Before changing my thermo it wouldn't get above 70 even in traffic. With the new one in it gets up to full temp within 5 to 10 mins. Always sits around 90 now.
Boost is back too ;)
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The more I read the more I'm convinced now it is one of the two(!) additional bypass thermostats that are in the cooling system.
My car does warm up but slowly.
My car has one in the coolant hose that runs the aux pump for turbo cooling after switch off and then another for the gearbox oil cooler by the looks of it.
Why they had to make a cooling system with three thermostats in is beyond me. I know the new main thermo is ok because ive tested it.
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Have a look here at the cooling section
http://www.mk5golfgti.co.uk/forum/index.php/topic,1797.0.html
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http://www.mk5golfgti.co.uk/forum/index.php/topic,75108.0.html
Online Parts catalogue
Go to illustration 121-030
That shows the full system for your vehicle
Then go to illustration 121-075 shows the regulator ( thermostat )
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Right.
Next step for the weekend is to change the two bypass thermostats. They are c.£20 each so another £40 but they are the only remaining 'active' parts of the system with the exception of the aux pump.
I suspect my local TPS won't have them in stock so it will need to be a weekend job but fingers crossed this will sort it once and for all. I'll test them both before fitting too. What what I've read they are supposed to start opening at 75 and be fully open at 87.
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7-10 days for getting a new bypass thermostat so instead of ordering blind I'm going to test the ones in the car at the weekend to see if I need one, two or none at all! Yes it will mean I need to drop the coolant twice but hey ho, at least I will know if it is actually the fault and what to order.
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Ok. Can someone check my logic on this diagram below?
Bottom left you can see the secondary thermostat for the turbo. If this is stuck open I can clearly see that this would mean coolant flow around the system would be bad.
The other secondary thermostat top right near the gearbox cooler wouldn't be as bad but would just slow the warmup down.
Make sense?
(http://s11.photobucket.com/user/wlegge/media/null_zpsde20c3d8.jpg.html)(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fa171%2Fwlegge%2Fnull_zpsde20c3d8.jpg&hash=6429e7116cf1b597de0886d3c14e0844c7feab1b)
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Are you diluting your antifreeze at the correct rate?
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I haven't changed it. Just using what was already in there.
Does it make a difference to warm up?
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I was just thinking if it was too strong it would take longer to warm up.
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You are over-thinking the problem.
You had an immediate change in the behaviour after changing the main thermostat and Coolant temperature sensor. So it is OBVIOUS to me that the "problem" is with these parts.
Just my opinion
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Undertaken some more diagnosis this morning.
Dropped the coolant and removed both of the bypass thermostat valves to check them.
Here's the first (as my car is a DSG)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fa171%2Fwlegge%2Fecd351fb-83c7-4616-b4de-392a13a64c5d.jpg&hash=3805f9970e2535eb83e80e1d985afe9cba94dc11)
Here is the second (turbo coolant line)
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fa171%2Fwlegge%2F9f073be0-cbfa-4cfb-b8c1-96adad450d52.jpg&hash=34f85110b95255f3dd33b88eca58afa37238d319)
These look like this
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fa171%2Fwlegge%2F657596AA-3C1E-4C7A-99EA-0B44404E259A.jpg&hash=bfe2c2a6a11b53545da236d1586f7c3735b50bb3)
And then opened up look like this
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fa171%2Fwlegge%2F91F45FFA-8304-46ED-AEC3-E7873FAA8693.jpg&hash=928e7d0384a62b3dbbe02b6762dd3c98c3ecdfc3)
You will notice that there is a brass active element in these. The pin position on the one in the photo here is fully closed but i had to use pliers to get it there. Both valves allowed me to blow freely through them in both directions when I took them out of the car, clearly both brass active elements are shot.
I put the brass thermostats in a cup of boiling water and they did expand, but then when i cooled them down and tried to press the pin back in it was very stiff, way harder than the small spring would overcome.
I've ordered them from the local TPS, c.£24 each inc vat.
I also tested the new temperature sensor against the old one (took ohm readings at various temperatures) and they are basically the same, so the old one was fine.
I've re-assembled the car with the old bits for now as we need to use it, but I've manually closed the thermostat pins so at least for the first warm up cycle i'll be able to see if it really has solved the slow warm up issue - I'm pretty certain it will have.
Through the research I've done it's very interesting to note that the cooling system design changed mid-05.
http://volkswagen.workshop-manuals.com/golf-mk5/index.php?id=5042
and then to
http://volkswagen.workshop-manuals.com/golf-mk5/index.php?id=5043
Spot the difference? Yep, no bypass thermostat for the turbo coolant pump line on the revised one. It's still there for DSG however.
Early 05 manual cars = Main thermostat + bypass stat for turbo cooling pump
Early 05 DSG cars = Main thermostat + bypass stat for turbo cooling pump + gearbox cooler bypass stat
Late 05+ manual cars = Main thermostat only
Late 05+ DSG cars = Main thermostat + gearbox cooler bypass stat
In short, just make sure you buy a 06 plate manual GTi :)
This thread here is also worth a read, many people seem to have the same problem and overlook the small thermostats. http://translate.google.co.uk/translate?hl=en&sl=nl&u=http://golfgtiforum.nl/forum/viewtopic.php%3Ff%3D12%26t%3D1582%26start%3D100&prev=/search%3Fq%3D4e0%2B121%2B113%26start%3D10%26client%3Dsafari%26sa%3DN%26rls%3Den%26biw%3D1572%26bih%3D883
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I have now worked through the theory of what is going on - see diagram below.
If (3) is faulty and just is open all the time, as the engine warms up it will pump warming coolant through the turbo and down that pipe, round to the junction at the bottom and directly into the main pipe towards the main thermostat (4). As this gets hotter and hotter it will make (4) open quicker than it should, rather than staying shut until the water from the engine is warm enough to open it.
I can also see how went sat in traffic my temperature would reach a nice 90c on the gauge (i.e. not much heat from turbo being produced and low water flow rate) but then when i pulled away a lot or drove where the turbo would be partially used it would drop down again to 80ish, because the water flowing around the turbo coolant line into the engine will be HOT, making the main thermostat fly wide open letting loads of cold water from the rad in.
(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fa171%2Fwlegge%2F25B7BDF3-3248-4DA3-9156-BDC3BEF01781.jpg&hash=13f1d867a8bb0380032cb0f2410f62939618e2e7)
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Have just got home after a run out in the car and just as expected it warmed up straight away to about 80c within 5 minutes from stone cold.
Took a while after that to get to 90 but then it stayed there too. It was 4.5c outside when I left home, just for reference.
I fully expect it to be back to its old bad self tomorrow morning as I did have to manually close the brass active thermostat elements in both the bypass stats to get them to shut, but they key thing today was to find the root cause of the problem which I've done.
So, a message to anyone who has a gti that takes longer than 5-10 minutes to get to 90c, "it's not normal and should be fixed!".
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So, a message to anyone who has a gti that takes longer than 5-10 minutes to get to 90c, "it's not normal and should be fixed!".
Yep - second that!
Great write up. Well done and thanks.
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Thanks, i'll make sure I post up once I've fitted the new two bypass stats just to close the story and do a final confirmation that they were the problem.
Annoying thing is that I didn't need to fit the new main thermostat or coolant sensor (£70 in total) but at least I've got peace of mind they are done anyway.
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That would be really good if you could 'finish the story'. Good info for the Forum.
No bad thing to change the 'stat though. According to my local Indy -and they have changed quite a few - he thinks there were a dodgy batch supplied to VW. Not made to the right tolerance and getting stuck with general muck and/or limescale. I can't back that with any hard evidence. I forgot to keep mine when I had it changed. If you still have yours and don't mind sacrificing it, you could cut it apart and have a look for evidence!
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Well done with your research and tenacity :happy2:
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I just have a pet hate of things that don't work as they should do. Just because the car is 8 years old doesn't mean it can't perform just like it has been delivered from the factory.
Just needs a bit of TLC !
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Useful.
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Its two years since I got rid of my mk5 GTI and it was an 05 and despite replacing the temp sender and what I now know was the 'main' thermostat it still wouldn't reach temp in the winter except on a very long drive and it drove me ABSOLUTELY NUTS as I knew it wasn't right despite being told by many that since it was colder it was to be expected. 40 mins and not reaching full temp? pah!
At the time I posted on here and did notice a few others saying the same thing, all 05 ish age hence AXX engines.
Well done on your perseverance and for laying that niggle to rest for me - I knew I was right :grin:
:star: :star: :jumpmove:
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I've got a very similar problem with mine and have already replaced both temperature sensors to no avail. Will give this a try before I bite the bullet and replace the main thermostat. Do you have a part no. for the bypass thermostat please?
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So I take it with these. If the temp takes ages to get there but once it does it stays at 90 were thinking the small thermos. If it gets warm quick enough but then can't maintain the temp at 90 it's the main thermo. And if it takes ages to warm up and then can't maintain the temp it's all three. Have I understood it right
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I've got a very similar problem with mine and have already replaced both temperature sensors to no avail. Will give this a try before I bite the bullet and replace the main thermostat. Do you have a part no. for the bypass thermostat please?
Just had a butchers on ETKA, the part no. of the bypass thermostat (or coolant regulator as ETKA calls it) is: 4E0 121 113, approx £22 (I haven't updated the price database on ETKA for a while so it's out of date).
:happy2:
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Ok, finishing the story for completeness - I've replaced both of these bypass thermostats today and now my temp goes from ambient (currently 5c) to 90c on the gauge in 5 mins flat and then is rock solid.
If you think you have problems you can remove these bypass stats really easily and just test them in a pan of water.
If you take them out try blowing through them first of all at normal air temp. They should be shut. They should start opening at about 77c and be fully open at 88c, co-ordinating with the main stat opening.
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So I take it with these. If the temp takes ages to get there but once it does it stays at 90 were thinking the small thermos. If it gets warm quick enough but then can't maintain the temp at 90 it's the main thermo. And if it takes ages to warm up and then can't maintain the temp it's all three. Have I understood it right
Well what I found was that with both bypass stats failing it just took ages to get to 90 but when there it held it ok.
One bypass stat failed (ie fully open), dsg one in my case, temp would get to c.75 and then climb very slowly from there.
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Yep, thats the ones I bought. I paid £46 inc vat for both from TPS retail prices.
I've got a very similar problem with mine and have already replaced both temperature sensors to no avail. Will give this a try before I bite the bullet and replace the main thermostat. Do you have a part no. for the bypass thermostat please?
Just had a butchers on ETKA, the part no. of the bypass thermostat (or coolant regulator as ETKA calls it) is: 4E0 121 113, approx £22 (I haven't updated the price database on ETKA for a while so it's out of date).
:happy2:
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So you have the main thermostat for the engine and then the 2 additional thermostats.
The other 2, are they BOTH 4E0 121 113 or do they have different part numbers.
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The other two are both the same.
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Right. Two bypass thermostats will be in stock at VW tomorrow. Is there a guide for replacing these at all. Or can someone tell me what I need to remove, time it takes, with any photos. Would really appreciate a few pointers before I do the job Sunday. OR if there is a guide somewhere I can't find it.
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Looking at the pictures it doesn't seem too hard.......
2 pipes going to a valve which is held on with clips.. I would imagine undo the clips either side and they come right out. :chicken:
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Best bet is to start with the one near the dsg, it's the easier on so can be good for gauging knowledge.
The one behind the front radiator, I removed the throttle pipe from between the n/s intercooler and TB. Then removed bottom hose from thermo from underneath the car. Then I undid the coolant hard pipe connected to the inlet manifold and could the pull up the hose with the thermo on the other end to easily release the top hose from it. Replace thermo and do reverse
Take a bit of time to remove the inlet pipe but good prep make the job quick / easier in the long run.
That was how I did it, perhaps easier ways, but maybe of some use
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Surely you don't need to remove the TB to get to the pipe :surprised:
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Surely you don't need to remove the TB to get to the pipe :surprised:
Erm no, just the silicone pipe connected to the TB :ashamed:
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:ashamed: :ashamed: :ashamed: :ashamed: misread
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Sorry to resurrect this, but I thought this would be the relevant place for good info :notworthy:
Anyway, I have had the secondary inline thermo replaced and it's worked wonders for my slow warm up. Up to temp steadily in 3-4 miles now. However, occasionally the temp will drop back fractionally to about 88 degrees and then go back up. I'm guessing this means I'm gonna have to change the main thermostat as well? Opinions please.
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Me too, this thread even to find about the other thermostats is immensely valuable. I've just bought our car and the temp gauge did not go above the first thick mark at 45 degrees. I naturally went straight for the main thermostat and changed it for a VW item the found out the ECT sensor had failed so got that changed, now it does go to 90 but takes 12 miles (sadly made a note each day this week) @ 65 mph on my 32 mile each way commute. So today I've ordered the bypass stat from my local VW dealer who has never sold one according to records and I think this will solve my lazy warm up.
Steve
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Read this. I changed my inline stats last month. Sorted the slow warm up. Did not take long and that included tea breaks.
http://www.mk5golfgti.co.uk/forum/index.php/topic,78341.msg817626.html#msg817626
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Sorry to resurrect this, but I thought this would be the relevant place for good info :notworthy:
Anyway, I have had the secondary inline thermo replaced and it's worked wonders for my slow warm up. Up to temp steadily in 3-4 miles now. However, occasionally the temp will drop back fractionally to about 88 degrees and then go back up. I'm guessing this means I'm gonna have to change the main thermostat as well? Opinions please.
Any thoughts on this guys?
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Either a temp sensor or man thermostat. If it gets to temp when stationary or in slow moving traffic then drops when you drive then it's the main stat.
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Cheers. It doesn't drop back specifically when stationary or low speeds. It's just going back those couple of degrees now and then when driving at any speed. Is the temp sensor also called a temp sender?
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Isn't there 2?, one on the battery side of the head and the other down in the thermostat housing.
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Isn't there 2?, one on the battery side of the head and the other down in the thermostat housing.
Two what? If you mean inline thermostats, then only DSG cars have two, manuals have one.
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I'd not be too worried personally. If it gets up to temp and then goes SLIGHTLY down and back up (once) and stays at 90...?
I'd say that to be main thermostat.
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Isn't there 2?, one on the battery side of the head and the other down in the thermostat housing.
Two what? If you mean inline thermostats, then only DSG cars have two, manuals have one.
Sorry two temp sensors. One in the head the other down by the main stat housing
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I'd not be too worried personally. If it gets up to temp and then goes SLIGHTLY down and back up (once) and stays at 90...?
I'd say that to be main thermostat.
Thanks. Yeah, i'm not too worried about it, it's nice that it actually gets up to temp now! Just a little annoying that something is still not right. It does it's drop and rise intermittently though, not just once. Might just live with it for now though and maybe try a new thermostat when I get my cambelt done.
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Isn't there 2?, one on the battery side of the head and the other down in the thermostat housing.
Two what? If you mean inline thermostats, then only DSG cars have two, manuals have one.
Sorry two temp sensors. One in the head the other down by the main stat housing
Oh right, cheers.
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Well I had my bypass thermostat changed today and the car warm up was a massive improvement, something close to 3 miles to 90 as opposed to 12 miles before the change.
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Ok, finishing the story for completeness - I've replaced both of these bypass thermostats today and now my temp goes from ambient (currently 5c) to 90c on the gauge in 5 mins flat and then is rock solid.
If you think you have problems you can remove these bypass stats really easily and just test them in a pan of water.
If you take them out try blowing through them first of all at normal air temp. They should be shut. They should start opening at about 77c and be fully open at 88c, co-ordinating with the main stat opening.
Hi guys, I hope you can help with my 'temperature problem':
I live in The Netherlands and have a 06-2005 AXX DSG mk5 GTI.
My temperature gauge reaches the 90 degrees celcius quite quickly, but I noticed it often points just a milimeter in front of the centered 90 degrees (so say 85 analog degrees celcius).
So I took al look in my climatronic, option 19.2, to see how many degrees my coolant temp digital is. I also used vcds a few times to monitor this temperature.
Digital readings say my coolant temp is around 74 degrees celcius.
I found out that the analog meter stabilizes at 90 degrees when in real life it is between 75 and 108 degrees celcius (stabilizes because otherwise people would get 'scared' seeing the fluctuations all the time).
Digital I can only get 80+ degrees celclius coolant temperature when I do a spirited drive and let it run stationary / traffic jam after that drive.
No real difference between city driving and highways, it just reaches around 85 degrees on analog meter within reasonable time (15 minutes city driving!?), but in real life (digital) this is only around 74 degrees and it won't get significantly hotter.
I think it should also reach around 90 degrees on accurate digital readings? (healthier for the engine?, because my oil temp is also under 90 degrees celcius because of this)
So one of the thermostats must be faulty...
Do I need to replace the MAIN-THERMOSTATE? Or is this one of the two (do I have two?) small thermostates?
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Tim before panicking I suggest you try reading and monitoring your temp with vcds
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Tim before panicking I suggest you try reading and monitoring your temp with vcds
As you i can read in my post, i did this; climatronic and vagcom.
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Tim. The smaller thermostats just control the warm up time by reducing flow till warm. However they will probably be worn and not working correctly because of the design of them. If your water temp does not sit bang on 90. Then it's either your main stat or the temp sensor itself playing up. I changed the lot on mine to ensure it was all working as it should.
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Tim. The smaller thermostats just control the warm up time by reducing flow till warm. However they will probably be worn and not working correctly because of the design of them. If your water temp does not sit bang on 90. Then it's either your main stat or the temp sensor itself playing up. I changed the lot on mine to ensure it was all working as it should.
Thanks! So in my situation it is probably the main thermostat?!...
You say 'if your water temp does not sit bang on 90...', do you mean 90 degrees on the analog meter or also on digital (climatronic 19.2) readings?
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I was on about the dash display analogue job on every vag I have owned it been the same
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I was on about the dash display analogue job on every vag I have owned it been the same
Sorry I don't understand what you mean (English isn't my native language). What was the same on every vag car you have owned? The difference between analog and (accurate/real) digital coolant fluid temp readings?
Who can tell me what readings you get on your mk5 gti climatronic 19.2 when you see the analog meter reaching the (stabilized) 90 degrees celcius?
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Sorry. I answered quickly whilst at work. All VAG cars (Volkswagen Audi Group) tend to show 90 degrees celceus on the analogue display on the dashboard. If it does not sit at a 90 degree celceus temp reading it tends to point at the thermostat
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Having read through all of this thread I'm still unsure as to wether my main stat, temp sensor or smaller bypass stats need changing.
The polar FIS reads about 65-70oc for water temp and the analogue gauge on the dash sits half between 0 and 90 let's say. To be honest I'm just going off the digital reading as it should be most accurate. It gets up to 70oc degrees pretty quickly 3-4 miles but then never gets any higher even on a long drive never seen it get to 90oc!!
What could be causing this issue the main stat or could the coolant be at 90oc and the sender not be relaying the correct temp measurement?
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Has anyone tried to change the inline thermostat (above dsg) without dropping fluids? If the expansion cap is kept shut, I would think not much coolant comes out?
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Has anyone tried to change the inline thermostat (above dsg) without dropping fluids? If the expansion cap is kept shut, I would think not much coolant comes out?
Yep :happy2: I did only lost just over egg cup amount. If I remember right I bent one of the hoses upwards. But defiantly quick and save fluid this way!
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Thermostat settings could be really too intricate to manage. However, you may not find any troubles when you adjust this with the help of user manual for your vehicle.
And suppose if you do not possess the user manual too, it’s not too difficult to get a new one. Just visit https://manuals.co/ and download a copy of it online for your vehicle without any charges.