Thermostat

4.2 V8 40v biturbo - 450 bhp
4.2 V8 40v biturbo - 480 bhp (plus)
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ecain63
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Thermostat

Post by ecain63 » Sun Apr 05, 2009 1:46 pm

My car 'may' have a thermostat issue according to Audi:

When they were checking the boost levels the other day they said that the car overheated. They said this may also be the reason why i wasnt getting full boost in the past. Since changing the boost / vacc hoses the boost is a steady 0.85 - 0.9 bar with standard map. Isn't that pretty much what it should be?

Its never ovrheated on me before and the guage has always shown 90 degrees once at running temp. I tried to get her to overheat this morning on the driveway as a test but to no avail as the fan kept kicking in.??

If the fan is kicking in to cool the engine then surely the thermostat is fine. Its a 7 hr job to change the thermostat and £15 for the item according to Audi and they said that if the thermostat is faulty then they would pay for the work and a new belt kit aswell. If it turns out to be fine then i'll have to fit the bill for the inspection (£700 + :shock: )

When i tried her this morning the touch temperature of the radiators were as follows: smaller, slimmer one (crossed by those shaped pipes) nearest front of car was not hot, even after a good ragging of the throttle. The one directly behind was hot, but im guessing no hotter than 90 degrees as per the guage. The fan directly behind this rad was visibly working when it got hot.

Are these normal results for the rads? And is Audi Poole having a laugh with me? Im starting to think that they are milking it a bit now to make a bit more cash for their quotas.

The water pump im assuming is fine, otherwise the engine would definately be cooked.
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Post by stunew » Sun Apr 05, 2009 2:17 pm

The radiator at the front which was not hot I assume is the air con condenser.

I just changed my thermostat while doing the cam belt and if audi are quoting 7 hours to only change the thermostat they are taking the p*ss!

3 - 4 hours should see the thermostat changed and another hour or so if the belt, water pump etc are being changed. Then again its the dealer so they will rip you off wherever possible!!

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Post by vinny » Sun Apr 05, 2009 8:44 pm

hey guys, im at the dealer in south africa, and ive actually replaced quite a few thermostats in the last two months on the V8 engines....
the A8 engine is a relatively easy thermostat to gete out (3-4 hours), but the RS6/S6 involves a bit more stripping (7 hours isnt over the top), so either find someone who can do it at less of a labour rate, or go see your bank manager and cough... :( with us, we normally suggest to the customer to replace the timing belt and all the rollers and tensioner, as its the same work....

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ecain63
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Post by ecain63 » Sun Apr 05, 2009 8:53 pm

Yeah, it'll need to be a full 'belt off' job. Another independant has also quoted 7.5 hrs to do the job. I know Grizz can do it in a morning and still have time for a tea and biscuits but from what i can gather he is Superhuman :notworthy:

Still doesnt answer the question though. Is my thermostat dead? The fans come on when it gets hot so isn't that the thermostat doing its job?
Now Sold!

'03 Daytona Grey RS6 Avant.
Bilstein PSS9's - bloody amazing.
275 Vreds.
MRC custom map with TCU.
Miltek Resonated.
Hi Flow filters.
Piano inserts with natural leather.
19" 'Plus' (Grey) rims.
Pioneer Avic-D3 (to replace RNS-D) inc DVD, Nav, Ipod Movies, Bluetooth and much more.

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Lig
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Post by Lig » Mon Apr 06, 2009 11:51 am

Hi ecain63,

When my thermostat went on the blink, I noticed that everytime I pulled into the drive and turned off the ig, the fans would stay on for a good couple of mins, everytime, even if I had just been a few miles. I couple of weeks later on a motorway run I noticed the temp gauge rise slightly past 90, then about a week later it went higher and I got the big STOP sign on the display. I then got the thermostat changed and all was fine again, and now everytime I stop and turn off the ig, the fans immediately stop running. IF your fans dont run when you turn off and the gauge is at a constant 90 then I wouldnt worry.

For info mine cost £500 all in including new thermostat and waterpump and cambelt (literally just the belt), from a specialist.

Lig.
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ecain63
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Post by ecain63 » Mon Apr 06, 2009 6:06 pm

Thanks mate. Yeah, sounds fairly similar to mine. The fans do every so often stay on after driving, but not every time like yours did.
I did find out today that the thermostat is not linked to the fans as they are on a different sensor. If it is a thermostat issue then it'll be a warranty claim for me.

Was the guage that rose above 90 the coolant or oil guage?
Now Sold!

'03 Daytona Grey RS6 Avant.
Bilstein PSS9's - bloody amazing.
275 Vreds.
MRC custom map with TCU.
Miltek Resonated.
Hi Flow filters.
Piano inserts with natural leather.
19" 'Plus' (Grey) rims.
Pioneer Avic-D3 (to replace RNS-D) inc DVD, Nav, Ipod Movies, Bluetooth and much more.

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