Coolant temperature sensor

[timsmith]

Hi

Im reasonably certain I have a problem with the ECT sensor on my A4. Whilst some of the time it reads a perfectly correct 90, it quite often fluctutates between 70 and 90. One minute it will read 90, and within seconds it will have dropped to 70. From googling, this sounds like a common fault.

My problem is that from saerching the internet, there seems to be different parts and different positioning for many of the different A4 engine models and Im thoroughly confused as to where I should be looking. Whilst I perfectly mechanically capable, Im naive when it comes to engines...

The car is 2004 A4, 1.8T 163.

Can someone please tell where I should be looking and offer any advice on changing this. My local dealer wanted £55+VAT labour when from what I can tell its a job which should take literally minutes.

Thanks

Tim

[kenney]

At the rear of the cyl head,there are 4 wires which are connected to it

[bez101]

Hi

Im reasonably certain I have a problem with the ECT sensor on my A4. Whilst some of the time it reads a perfectly correct 90, it quite often fluctutates between 70 and 90. One minute it will read 90, and within seconds it will have dropped to 70. From googling, this sounds like a common fault.

My problem is that from saerching the internet, there seems to be different parts and different positioning for many of the different A4 engine models and Im thoroughly confused as to where I should be looking. Whilst I perfectly mechanically capable, Im naive when it comes to engines...

The car is 2004 A4, 1.8T 163.

Can someone please tell where I should be looking and offer any advice on changing this. My local dealer wanted £55+VAT labour when from what I can tell its a job which should take literally minutes.

Thanks

Tim

as kenny says at the back but you cant realy see it u have to feel it and its very tight back there make sure the cars cold b4 you remove

[timsmith]

Hi

Thanks for the replies.

Ive read that some models have two sensors - is this right and if so, does my model just have the one (or isnt it as simple as that). Is it possible to know which "colour" sensor it is, or again does this vary?

Ive just used a friends VAG cable and it does report an intermittent error with the sensor

01039 - Coolant Temperature Sensor (G2)
30-10 - Open or Short to B+ - Intermittent

I guess this means that it is the sensor at fault than the gauge?

Thanks

Tim

[nevo]

Hadthe same problem with my a4 tdi ,fluctuating from 90 to low scalefor a while then back up,get a genuine vag £30 with a new o ring,bit awkward at the back of the head,its held in place by a horseshoe shaped plastic clip,no need to drain down completely ,just gently ease out the sensor and catch the coolant with some sort of funnel,you'll probably think hows this going to seal with just a o ring ,but it will,top up with coolant and away you go,its a bit tight but easy job,just a few skinned knuckles,you can see them on e baywhat they look like ,but on the car its obscured by the connector,just look out for the u shaped clip

[RickT]

Take a look at this thread.


http://www.vwaudiforum.co.uk/forum/showthread.php?t=37108&highlight=Coolant+Temperature


Cheers


Rick

[timsmith]

Hi everyone,

Thanks very much for all the replies - very useful.

I can now clearly (well - reasonably clearly) see the bit I need to replace and Ive got a spare part from a supplier on Ebay.

However, Ive got one more question. In situ in car, the clip is positioned such as the closed end of the clip is facing the cylinder head and the open ends are facing the firewall.

Whilst it will be possible to get the clip out (using a screwdriver to flick it), getting teh new one in in that position would be partciularly difficult just because of the location.

Whilst I can tell that the holder that the clips goes into doesnt allow the clip to be put in at just any orientation, is it symmetrical so that I could put the clip in with the closed end at the firewall end where there is more handroom.

Can anyone confirm whether this is possible or whether it has been be replaced in teh saem "orientation" as it came out?

Thanks

Tim

[nevo]

I would say it does'nt matter which way it goes in ,its not handed,put it in which ever way is easiest,try prising one side off first then turning it slightly and withdraw,the tdi is slightly different but still a bit tight,I would have gone for a genuine unit myself ,but see how it goes

[RickT]

Whilst it will be possible to get the clip out (using a screwdriver to flick it), getting teh new one in in that position would be partciularly difficult just because of the location.

The clip can fit either way... the way it is now.. or the opposite...

The platisc housing the sensor sits in, has some cut outs on either side..

TIP...

Dont pull the clip completely off, if you pull it off about 2cm.. the sensor should pull out, then just push it back on....

BEFORE careful it does not drop into the engine bay though!!

Rick

[Martin F]

Ive read that some models have two sensors - is this right and if so, does my model just have the one (or isnt it as simple as that). Is it possible to know which "colour" sensor it is, or again does this vary?



Did you ever get an answer on this one?

My car has started to throw a coolant sensor(G62) fault code and I want to make sure I get the right sensor.

If the one on the back of the head is the one to change, what does the one at the bottom of the rad do?

[nevo]

Yes its the one at the back of the head.easy job about half an hour.

[Martin F]

Thanks.

So does anybody know what the one at the bottom of the radiator does?