Coolant temp

[rich83]

stwrt

[chris s]

Thanks Dan you live and learn eh.... Interesting thoughts from rich wig??

[GrayMK5GTI]

My thermostat failed when I bought my ed30. No fault codes, just temp gauge dropping when coasting.

Part was around £30 from VW. . . Fitting yourself is not fun at all - basically the whole front of the engine has to come off. I gave up and got Awesome GTI to do mine. The tech said he hopes to never do another one of those

[chris s]

Exactly what I found out... Quoted £224 all in by the loa all vw dealer so worth it for the amour of work needed

[chris s]

A quick update to this issue... As I eventually worked out the problem I had was down to a knackered main thermostat.  Cost me £224 all in so not cheap but the gauge is upto 90 after 5mins and is rock solid! Not noticed any better mpg and I drive like a granny on my commute so can't comment on performance but expect both to be better

[lukemk5gti]

Definitely have the same problem. I really don't like paying vw to fix my car but judging by people's reaction to this work I might have to.

Did you just bring it into vw and they determined it was the main thermostat or is this a trial and error approach and you fix one part after another until you fix it?

[v4rley]

Pleased you got it fixed  even at that cost  will be beneficial especially as winter approaches...

[chris s]

I wasted my money by changing the coolant sensor first, but if your symptoms are like mine I'd advise going to vw and ask them to change it.  I'd prefer to use a good Indy garage too but vw is next to my work now.  They did say they had to diagnose themselves but surprisingly they agreed me.

[lukemk5gti]

I'll take a look myself tomorrow and if it all looks too much I might just book it in.

My next question if I anyone can answer. Is this sensor not just to show when you get to the ideal operating tempwrature or does it actually cause your engine to operate differently.

For example I'm driving 6 hours but the temp still shows about 80degrees. Will my engine now pump more fuel in to get it up to operating temp?

Does it actually have any detrimental affects?

[chris s]

I'm no expert but I would have thought it would be like running with a choke out?!? Ie possibly over fuelling and I think the ecu holds performance back a litt but could be totally wrong

[GrayMK5GTI]

I'm no expert but I would have thought it would be like running with a choke out?!? Ie possibly over fuelling and I think the ecu holds performance back a litt but could be totally wrong

I think your right. Mine was definitely holding back when the stat was busted

[lukemk5gti]

So I spoke to VW about it and they said it's 3 hours work so total cost is just shy of  €400!!!!!

From the thread I've gathered that I won't (which I don't) get an error code but I can have VW live read with VCDS to see if the main thermostat if relaying info.

I've booked in for laser alignment with VW on Friday so they said they can scan it then and find out if it is at fault.

In terms of the work, I've changed brakes, suspension, dv and all service items on my car. Should I tackle the main thermostat myself or is it too much of a heartbreak and am I better off getting VW to do it?

[chris s]

That's very high, I had mine done at VW Benfield in Newcastle for £224, and beeline it is about 3hrs work, and not easy work, so depending on how competent you are with some spanners I'd get the garage to do, but it's your call.  Maybe suggest they contact the place I had it done for a price match?

[OllieL]

Thermostat as said above. You could have verified the sensor was working correctly with VCDS before rushing out to buy new.

Don't rely on fault codes for errors, live data reading of measuring blocks is far far more useful

Sorry to resurrect this, but which blocks show the water temp sensor readings?
Am going through the same process and I have the error code P1285 (engine coolant sensor 2 circuit high, lower limit not reached) with fans running constantly.

I’m hoping this is just an over cooling issue with fans running maximally all the time, but would really appreciate guidance of which blocks to check for sensor data.

Thanks

Ollie

[pudding]

What scan tool do you have?  You can't miss coolant temp with VCDS under advanced measuring blocks, it's one of the first ones in the list.