Temp Guage Showing Low Temp

[Mad mike]

Hi folks

My 2003 A4 TDI Avant multi has been showing a lower than normal temp after warmup ever since I bought it just over two years ago

It used to sit about 80 (kind of 11 o clock position) but over the last few months it's struggling to move up much at all, now sits about just over the first measure.

Typically now I'm thinking of selling it all the little niggles that I have put up with come back into focus!!!

Any ideas what the problem could be? Is it easy to fix as a DIY job?

Any advice appreciated

Regards

Mike

[pippip]

Most common cause is a stuck thermostat. Here are instructions http://www.audiworld.com/tech/eng.html
(a few down on the list)

Not sure if I'd say it's DIY, depends on you.

[yaman]

Any ideas what the problem could be? Is it easy to fix as a DIY job?

Any advice appreciated

There's a good chance that the coolant temp sender is kaput.

Fairly easy wee job...... when you find it!!

It's at the back of the engine near the fire-wall...

http://www.youtube.com/watch?v=WyKRg...ure=plpp_video

Regards
Jim

[Mad mike]

Thanks chaps given the complexities of getting to the thermostat I think I'll start with the sensor first, lol

Cheers

Mike

[Boat_face]

Hi Mike

Having changed both the coolant sensor and the thermostat I'd say that probably the thermostat is the easier of the two. The temp sensor sits behind the EGR and is a bit of a pain to reach. Top tip would be to tie some dental floss to the plastic clip for the temp sensor, it's very very easy to drop and even easier to loose! With regards to the thermostat you shouldn't need to remove the alternator and if you take the engine cover off first you'll get a good idea of where it is. Still tight but not nearly as tight as the temp sensor. If you want a visual step by step this is good:

http://forums.vwvortex.com/showthread.php?1730221

For me changing the temp sensor fixed things. Now a year on similar problem again so have changed the thermostat. It's done 8 years and for £20 it's worth a go and judging by posts here isn't a bad bet.

All the best

[benjie]

Just changed my thermostat today (20min job) and did my coolant temp 9months ago. From your symptoms, I'd say thermostat as it's not really reaching 90. I always found that, with the coolant sensor, the movement of the temp gauge would be erratic.

AS Boat_Face says, thermostat is definitely easier - be prepared top lose about 4L of coolant though, I unclipped the undertray at the front, pulled it (bent it) down to the floor from behind the bumper lip, then stuck a bowl under there. Make sure the engine's cold. I used post number 2 on this thread to help me. Quite an easy job.

[Mad mike]

Thanks guys for this very helpful advice, think I will start with the thermostat then and see whether this fixes things 


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[1613gary]

your thermostat is stuck open mate

[toff]

Hi,

I also have a 53 plate A4 Avant and had the same problem..

I tried changing the coolant temp sender first.. no luck, then tried the thermostat which cured the problem.

It's not a difficult job really.. just ensure you have a magnetic pickup tool in case you drop one of the bolts for the thermostat housing!

Al.

[benjie]

Hi,

just ensure you have a magnetic pickup tool in case you drop one of the bolts for the thermostat housing!

Al.

May have done that! Quick trip to my local hardware shop fixed it! Going to order a genuine one tomorrow though.