S4 b6 temp gauge

[ven]

Hi all, some advice off the experts please. Drove to work and temp gauge never moved, stayed at minimum. At one point it jumped 1/2 way to 90oC then back to minimum. So everything is pointing  me to the  temp sensor. From what I could find it’s at the back of the engine in between the heads. A green sensor with plug. Does this sound right to you guys . Any info or thoughts would be greatly appreciated. Would rather do myself than risk taking it to a garage . 
 

Cheers 

[Magnet]

Hello Mark,

From your description of the symptoms, it sounds more like a connection issue rather than a sensor fault. Generally sensors fail and don’t revive. 

I would be first be armed with a can of contact cleaner and starting there. 

Kind regards,

Gareth. 

[ven]

Cheers Gareth for reply. Thinking that myself. Drove back from work, temp rose to 90 per normal within a few miles. All good yay !!!! Nope, dropped to minimum instant, blink of an eye. Stayed there all the way home. Stopped off for a couple of mins near home, then ign on, temp gauge going up, started and as if nothing happened! Stayed at 90 for the last mile. 
 

Elec clean! What is easiest way, I can’t even see the little bugger down the back. Any easy way to get it unplugged to spray copious amounts of elec cleaner in there? Any tips would be welcome, kind regards 🙂

[Magnet]

Hello Mark,

Access?? Sometimes/often attacked from below - if you are blessed with/have access to a pit or hoist - but who has normally! Even taking the undershield off on your back on the floor takes some doing, leave alone then getting underneath to get up to components from under.

I guess that’s why investing in an hour’s labour at a trusted local garage becomes worthwhile. Having said that Mark, it could well be worth changing the sensor at the same time if resorting to this. If so, I would suggest only using Bosch if not a genuine VAG one. 

Kind regards,

Gareth. 

[ven]

Thanks again Gareth, well it is booked in for next Thursday...........feels forever away. I do have ramps which i used last week for the oil change. I have a look under the engine cover and straight away those pesky clips they use. i dont have a tool(about to order for future uses). Also there are quite a few pipes near and around the air inlet pipe at back. You know what happens next........something breaks! Yes new switch with going to the trouble, after all , if i can unplug it, for the sake of £20 or so, might as well change it. Worst case scenario, its ruled out if issue continues. Reading up, it does seem a common issue, not with just the s4.  I bet it was so easy to fit when the engine was out🙄  😂

 

Thanks again Gareth, fingers crossed then, back end of next week i will update the thread, good, bad and/or  ugly. That may help others in the future.👍

[ven]

Got it up and ramps, for me no easier, cant even see to get close. Above impossible to see without taking those stupid hose clips off. So nipped out, new can of elec clean and the hose clip pliers. In the time i drove back and got up on ramps, i though best leave it incase any clip or pipe gives. Then i am stuck. The best i could i aimed copious amounts of elec clean. The gauge actually worked 90% of the time i was out........

 

So next week it is, not worth being totally stranded. Ordered the sensor as a back up, just in case(as they do order on the day) they cant get one straight away. Bought a febi bilstein OE one for £12. 

Audi OE 059919501A