What's my issue then?

[Carefree69]

Ok, weird one this because my symptoms seem different to everyone else's I've read about.

Basically after a 14 mile drive into work yesterday and as I was crawling into the yard at work my temp gauge was reading just a tad to the left of 90 degrees. Once the engine had warmed up on my way in it was sitting where it should bang on 90, until I momentarily slowed down and stopped to open the gate. I know full well that VAG cars basically should just sit at 90 once up to temp and nothing should change this.

In addition, my mpg was lower than usual. I spent most of yesterday looking on here at threads regarding the thermostat or temp sensor BUT most of the symptoms I've read about say that the temp gauge is well below 90 when driving but creeps up to temp when stationery. Well, mine appears to be the opposite. When driving at road speeds it sits at 90, but when I slow down to a crawl or stop the needle creeps slightly to the left.

On my journey home last night it was exactly the same.

Could it still be the thermostat??

By the way, had the cambelt and water pump changed a week ago by a highly recommended Audi Indy, could it be related??

 

[AndyParker]

I have the same symptoms as you but had forgotten to mention it to my tuner. He however picked up that I need a new thermostat so it's booked in for a few weeks time.

 

[Carefree69]

I'm thinking thermostat too. Just got into work again and exactly the same happened, got up to temp and bang on 90 degrees, then shortly after stopping or slowing down the needle crawls slightly to the left. My heaters seem to be working but my mpg has dipped.

It's in for a service on Wednesday so will get them to take a look.

 

[nitrdc2]

100% thermo. Had exactly the same symptoms fortunately it was still under warranty.

 

[LEE69]

Agreed the stat.

 

[Carefree69]

Cheers all

 

[Carefree69]

Next question, obviously it's Sunday so I can't call my Audi indy for a price, but roughly how much are they likely to charge me for a new thermostat?

I'd do it, but I'd screw it up.

 

[Carefree69]

Right, just got back from my Audi Indy (vwauditec in Chelmsford who come highly recommended) and as well as service the car they ran a full diagnostic on the engine and no fault codes found. The tech took the car out on the road and assures me that the temp gauge did not move from 90 degrees, the coolant, oil and everything else ran at correct temps.

I pointed out that the mpg had recently dropped as well as the gauge moving slightly to the left but he told me in all his years working on Audis he had never known thermostats fail on my year car (2010), and he said the other techs who work there all said the same. I'm slightly confused with this as according to this excellent forum it appears that actually stat failure is very common.

He told me to keep an eye on it and to let them know should the symptoms persist.

Low and behold on my drive home i stopped once up to 90 degrees and after a while the needle moved a couple of mm to the left.

I have a dilemma now because I had intended on claiming for a new stat through Warranty Direct, and when I asked if they could just change it anyway he said that the Warranty company would want to know what had failed, and because as far as the garage are concerned nothing is wrong they won't be able to do it, or words to that effect.

***, I'm certain there is an issue, vwauditec reckons the engine and cooling system is running perfectly.

What now? Yes I could go elsewhere but to be honest I've been pretty pleased with them, they recently serviced my vRS and did the cambelt/water pump on the A3.

Any advice appreciated. In fact, if any of you know how to change the stat and can do it, I'll happily throw you a nice drink.

 

[Carefree69]

Anyone?

 

[vw754]

you need to replace coolant sensor ,its located in a pipe close to the cambelt cover,has a plug going to it.
they go faulty(very common) wont come up as a fault,because its still working,but giving you wrong readings,also it works like a choke...it sends a signal to the ecu when cars hot,telling it to inject less fuel,when they go faulty,cars basically running on choke all day long....using more fuel.
parts abot£28 genuine,or a tenner non gen....easy fit,no brainer.

 

[Carefree69]

Actually my Audi Indy said it could be the sensor after I took it back for them to look at but after further tests they changed the thermostat and hey presto, now back to being bang on 90 degrees and mpg back up.

They still maintain that mine is the first common rail engined thermostat they've had to change.

Cheers all for your input.