Engine Temp dial problems

[RobUK]

Hi all,

was driving along the other day and noticed that the engine temp needle was all the way down to the left, as if the car was turned off or not warmed up.  This was strange as id been driving for about half an hour and saw it on 90 degrees just before.  Then i saw it suddenly come back to life and go to 90 degrees, then it instantly dropped back to the left in the cold position.  This has been happening on and off for a week now.  Any ideas what could be broken or, hopefully, loose??? 

I would like to see if the cable to the sensor is in correctly, but i have no idea where in the engine the sensor and plug is, is it the same sensor, the green one on passenger side of engine,  thats used for the temp info when starting the car?

The car is a Golf GTI 2002 Mark4 2.0L

thanx everyone

Rob

[RobUK]

hi all,

used vagcom on the car last nite and it came up with the error "coolant temp sensor, signal too high".  Cant remmeber the exact code, i have it written down at home.  Reset the codes and turned the car on and off a few times, no faults came back.  Will check again tonight. Can someone point me in the right direction to the sensor in the engine so i can check the connections or even fit a new one.

thanx Rob

[GazB]

The coolant temp sensor is dead easy to change just hard to explain what it looks like without a pic, I did mine last year and just asked the dealer to point it out to me under the bonnet first.  Once you see it you can see how easy it is

edit, if i remember correctly the part is about £20

[RobUK]

Thanx for the reply gaz,

decided to finally fix the other problem i've been having regarding starting the car, i mentioned it in another post.  I think it was you gaz that said try replacing the ecu temp sender in the engine, so i rung Guilders VW to get a price on a new ECU temp sender and a coolant temp sender, he said he didn't know what an ecu temp sender was, he seems to think i've got confused and the coolant temp sender and ecu temp sender are actually the same part.  does this sound right cos im confused as hell.  Im sure you pointed a sender out on the right side of the engine gaz as ecu and they said the coolant sender is on the top left of engine.

HELP!

Rob

[GazB]

Hi mate, from memory I am sure that it is on the right as you stand in front of the car , may be wrong tho. unfortunatly I got a derv now so I cant go and look. sorry

[RobUK]

hi, went and got the new coolant sender, apparently its 2 sensors in one.  One for the dash and the other for the ecu.  So i took out the old sender and replaced it, right side of the engine, just like you said gaz, needle hasn't dropped since. Also the car feels a bit more sporty, starting better aswell.  But only time will tell if it still acts up in winter time. Changing the sender took about 10 mins, with 90% of the time trying to get the wire connector off. 

Rob

[GazB]

Cool, glad its sorted