A4 Temparature advice, PLEASE ADVISE ME

[markcass]

Hi everyone,
I just noticed today that my A4 2.8 Quattro 1998 model, seems to take ages to get to the correct tempatature 90. I was driving mostly in town conditions and a bit of duel carigway aprox 50mph. But it took about 6 miles (20 mins)to get up to temparature. Them i parked up for 25mins then when i drove it again it took about the same again 6 miles (20 mins). Is this normal????? I have had cars before and when the thermostat is gone on the motorway the temp normaly drops, but mine is not doing this. So i presume my thermostat is ok. Also just a point could be linked. I changed the plugs a few days ago, they had been in for aprox 11000 miles. The old plugs were quite black on the ends with a little bit of carbon build up (dont know if this is normal) But i thought it could have been running rich mixture (maybe on choke). I have had the car tested on emisions machine and they told me it was exelent emisions and everything was ok. WHAT DO YOU GUYS THINK! PLEASE GIVE ME SOME ADVICE.
(AFTER READING SOMETHING ON THE FORUM I CHECKED THE CAR AGAIN AND IT SEAMS THE RADIATOR COOLING FAN IS ON CONTINUASLY WHEN THE ENGINE IS RUNNING????) WHAT CAN CAUSE THIS HELP NEEDED URGENT.

 

[AndyMac]

Could be thermostat, depends whether it's stuck open, closed or in between as to the symptoms. An easier fix would be to change the temp sender unit, common fault on A4's. Mine was playing up and caused erratic idle and stalling when cold, as it not only feedsback to the engine temp to the gauge, but also to the ECU, which could account for sooty plugs, (telling the ECU the engine is still cold, when it's not).
It's only £20 from a dealer and is a simple (ish) DIY job.
You should have 2 fans, one runs all the time the other is temp dependent.

 

[markcass]

Could be thermostat, depends whether it's stuck open, closed or in between as to the symptoms. An easier fix would be to change the temp sender unit, common fault on A4's. Mine was playing up and caused erratic idle and stalling when cold, as it not only feedsback to the engine temp to the gauge, but also to the ECU, which could account for sooty plugs, (telling the ECU the engine is still cold, when it's not).
It's only £20 from a dealer and is a simple (ish) DIY job.
You should have 2 fans, one runs all the time the other is temp dependent.

Hi Andy, Thanks very much for your reply. After looking at some posts on here last night i decided to take my car and get it checked with vag.com today. He did a complete system check and there was no faults what so ever? I had a 2.8 Q before and had a prob with the temp sender sencer and that showed as a fault on vag.com but this time there are no faults showingon this one!

There is 2 fans one is a viscous fan and again was checked today and been told its fine as it spins continuesly but can be stoped with your hand when the engine is hot. The other fan i thought was the aircon fan which only works when the aircon is turned on!

Going back to car temp gauges, although it seems to take a long time to warm up, it does get to 90 and sit there. But the oil temp only gets to maybe 62 or 65 hardly moves? I am surprised this does not show up as a fault on vag.com! WHAT DO YOU THINK ANDY? OR ANYONE ELSE WHO MIGHT READ THIS POST. ANY IDEAS WELCOM. CHEERS MARK.

Oh i also tried to put photo of my car on my profile on here but does not seem to put it on my posts????

 

[AndyMac]

Sounds like thermostat is stuck open if the oil temp isn't reaching normal 110 degree operating temp. Does oil temp rise if you just let the engine idle for 20 minutes?
This is the exact same problem I had on my 2.8Q, and it was a combination of temp sender and thermostat. I don't think the temp sender will register a fault on VAGCOM unless it completely fails as how would VAGCOM know with nothing to compare it against? What colour temp sender do you have, as they changed the design and the latest is now green, the original was blue.
I'd replace it first anyway just to rule it out as it can cause all sorts of problems if it's misreading.

 

[Broken Byzan]

I say thermostat, but get a good quality one as i have found that the cheaper pattern ones seem to fail more than the genuine article

 

[markcass]

Thanks Andy and Byzan for your thoughts on this matter i will try both your ideas out then get back to you and let you know.
Cheers Mark.:thumbsup:

 

[markcass]

Ok Thanks to Andymac and Byzan for there thoughts and advice on this matter. I have now done what you both advised changed temp sender and also thermostat (including new waterpump and cambelt and tensioners). Now my engine temp gets there a lot quicker and stays there and my heaters are a lot hotter. Also the best bit i have gained a big improvment in my preformance, car is a lot quicker. Now only one prob left Oil temp still not getting to 120, its only getting to about 70. What do you think? I was thinking maybe oil temp senser but not sure if it has one and also where it is? Any help and advice would be very welcom.

Thanks Mark,