RS246.com Forum :: The World's #1 Audi R, S and RS Enthusiast Community

Hi All

I have a b5 rs4, and today the temperature needle isnt going to normal temperature , usually it it sits at 90 once warmed up.
For some reason its going up slightly but not more that 65 degrees, but when the car is stationary its going even lower, what could it be.

Also when switching the air blower on 16 degrees its blowing out warm arm.

Can anyone please advise, im getten worried..

Sounds like either a temp sensor or thermostat issue.

Do the sensor first, as its easier/cheaper. And if your going to DIY, then when you change it and it's a black type, then this is troublesome anyway. Needs to be replaced with the newer green type (059 919 501A)

Thermostat will be a timing belt out job, along with putting the front end in the service position.

Or alternatively get it checked by someone with VAG-COM, to see if there's a fault in engine or instruments for the temp sensor

HTH

If it's the Zeshan I am thinking it is, bring it down and I'll plug it in FOC, just PM me.
Will read coolant temp in measuring blocks on VAG COM and compare to gauge.
Will also check for a coolant temp fault in DTC memory and will check if you have green or black as R33V says.
I had slow warm up and up and down needle and alas it was the thermostat and incorporating it into an early cambelt and water pump change made sense for me as labour's the same.
16 degrees on climate display and hot air from heater isn't necessarily bad if aircon isn't meant to be operating, these engine create their own microclimate so will warm up the ambient air while stationary.

Definitely change to a green temp sender anyway first, the black ones fail sooner or later and it is a 15 minute job (as long as the old one isn't stuck in the pipe work)

Also , don't discount a faulty cluster.
Recently had this with my S6, and thought it was a 20 quid temp sensor.
Ended up being a 600 quid cluster !

I'd say its almost certainly the thermostat - had the same problem on both my B5's now. Fortunately the first one was replaced during the cambelt change, not so lucky with the second....

I'm so glad I did mine when the belt was done!

Same symptoms with mine - pesky thermostat!

Mine went at 8k miles before the 2nd belt change was due (66k miles), presumably Audi didn't replace it at the first change.
I'd be well pi55ed off I'd just spend £x on a belt change at Audi only for thermostat to then play up soon after - it must have happened to someone!
My old S4 had a new water pump not long after a belt change at Audi, it would appear from the receipts that the owner didn't have to pay for it

tHANK YOU ALL FOR YOUR ADVICE.

Took the car down to Doug today, he checked it all over and it was the little green temp sensor that needed replacing. Working absolutely perfect know.

That was or lucky or had you recently had a belt change with thermostat?

doug at mrc changed the belt about three months ago.

Ahh - in that case you would have had a new thermostat as Doug changes it as a matter of course during the cambelt change, unlike Audi and some other "specialists"

Glad it was the cheaper route!

Looks like I've started having this problem with the coolant temp guage on the instrument cluster over the weekend. Anybody tell me where I find the temp sensor (059 919 501A per Virdee's post above) so I can chck if it's black/green and slap a new one in?

Thanks!