MK5 GTI not heating up.

[Managh]

Driven the car last night and this morning and it's taking forever to warm up.

Last night I was driving down the motorway, temp gauge normal at half way, and when I came off I noticed the gauge had dropped down to a quarter. It then stayed like that for the next 2-3 miles.

Then this morning I drove 15 miles and it only just got to half way and when coasting it seemed to drop back down again.

The outdoor temp was around 0 but it should still heat up sufficiently?

Any ideas?

Thanks.

[doylebros]

This is worth a read

http://www.mk5golfgti.co.uk/forum/index.php/topic,78341.0.html

[lukemk5gti]

Your thermostat is gone. Whether it's the main one or not is up to debate.

I had my main one replaced last week and now it heats up to 90 whereas before it only got to 75 on motorway and 90 in traffic.

Now it heats up to 90 but due to icy cold weather it does take about 15mins

[Managh]

That's brilliant, cheers guys!

Does anyone have the part number for the 2 thermostats?

Might as well change them both.

[doylebros]

This is the main thermostat

http://www.partscats.info/volkswagen/en/?i=cat_vag_models&brand=vw&number=1714&set=1728&ein=2007&f=474&hauptgr=1234567890&hg=1&grf=012175420&bf=12175&hgug=121&ug=21&parent_id=2338016&detail_id=2338021

And the regulator part number is in the previous link from Sky Jawa

(The coolant regulators be it 1 or 2 are the same part:

4E0 121 113)

[lukemk5gti]

That's brilliant, cheers guys!

Does anyone have the part number for the 2 thermostats?

Might as well change them both.

I've tackled every single job on my car to date and would consider myself fairly competent but was afraid to tackle this. The whole front end apparently has to come off to do the main one.

Might be worth looking into before you buy the parts. Although if you're a mechanic, my bad! Good luck!

[gtgeorge]

my gt tdi bkd is pissing me off doing this, takes a good blast to get it to warm up, otherwise it takes a good 20 - 30 minutes to reach 90, but it stays there doesnt drop so thought thermostat was okay.

[Managh]

Well I've driven it again today and it seemed to be fine. I'll keep an eye on it and see if it does it again.

[Hawkes41]

I've tackled every single job on my car to date and would consider myself fairly competent but was afraid to tackle this. The whole front end apparently has to come off to do the main one.

Might be worth looking into before you buy the parts. Although if you're a mechanic, my bad! Good luck!

You don't need to remove the front end, to replace the main thermostat. I did mine a couple of weeks ago. I used this guide:
http://www.pelicanparts.com/techarticles/Volkswagen_Golf_GTI_Mk_V/31-WATER-Replacing_Your_Thermostat/31-WATER-Replacing_Your_Thermostat.htm

Note that it does show the whole of the front end off but only so that you can see all the parts. Hope this helps

[SkyJawa]

We had the stat done by VW under warranty and it fixed the car not staying at 90,  had major rows with them as they refused to do the regulators as the car was also taking an age to heat up.

Finally got round to both regulators being changed the other day and BAM, its up to temp in minutes.  Stupid VW.

I asked for the old ones, took them home and checked the brass element in boiling water, sure enough one was terrible, the other was better but not convinced working 100%.

[tyrekika]

What are the regulators and where are they located please

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