Cooling fluid just over 50 degrees Celsius...

[1975DCS]

I have just recieved my S2 back from some big maintenance (fluids, belts, oils, thermostat, waterpump, multisensor, rear diff rubbers and AP brakes), but just like before the watertemp does not seem to exceed the mark after 50 degrees (is that 55 or 60?) with this cold weather. Only when I idle the car during some refuelling the temp is nearing to about 90 (until the fan kicks in).

What could be the case? Thermostat is just new and did not help...

[s2driveruk]

sounds like the multifunction temp sensor is on its way out....probably see slightly poorer fuel economy too. Mine is doing the same too and i know its been like 6 years since i changed it so is probably due a change....

[newsh]

Give the MFTS a tap with a spanner and see if that helps. The other thing is to keep the cold air off the sensor, do you have the rubber boot still, mine was split so I removed it and this symptom got worse I think.

[1975DCS]

Thanks guys! unfortunately the Multisensor has also been changed (on my request, but the mechanic said it looked worn anyway).

Is the rubber boot something around the sensor to isolate it? Like the piece written by Porkis a time ago?

[newsh]

Thanks guys! unfortunately the Multisensor has also been changed (on my request, but the mechanic said it looked worn anyway).

Is the rubber boot something around the sensor to isolate it? Like the piece written by Porkis a time ago?

Yes, Porkis mentioned it, I think you could try splitting a bit of hose and fitting it round the sensor, I may have a go at it myself today and see what happens. Not easy to get to though is it, I still have the scars from messing with it last weekend.

[philS2]

i wrapped a bit of old coolant hose around mine and it was higher by about one notch on motorway runs.

[terrybullwon]

ah!!!!!
I changed mine and now i see little move ment and then a jump to 90 when the fan kicks in!!!

[1975DCS]

sounds like the multifunction temp sensor is on its way out....probably see slightly poorer fuel economy too. Mine is doing the same too and i know its been like 6 years since i changed it so is probably due a change....

Well I only have it for 2 months... 1 month driving, 1 month maintenance... But both temperature and consumption has allways been bad: 220 km on half a tank...

[1975DCS]

Give the MFTS a tap with a spanner and see if that helps. The other thing is to keep the cold air off the sensor, do you have the rubber boot still, mine was split so I removed it and this symptom got worse I think.

It looks like the sensor is already wrapped in some sort of black rubber... Could it be that Audi has (finally) modified it?

[1975DCS]

I have an digital temp meter with probe from the company I work at.
What would be the best place to measure the temp in order to see if the sensor is reading correctly?

In other words: were do you want the water to be 90 degrees? And is the best place to measure so?

This night the temp was between 50 and 50+1 so I opened the bonnet and measured different places and between 40 and 78 came up the display. Trouble is that in this one minute of measuring the temp has gone up to 50+3. By the way: The rear of the block seems to be most warm...

[Jamo]

I have just recieved my S2 back from some big maintenance (fluids, belts, oils, thermostat, waterpump, multisensor, rear diff rubbers and AP brakes), but just like before the watertemp does not seem to exceed the mark after 50 degrees (is that 55 or 60?) with this cold weather. Only when I idle the car during some refuelling the temp is nearing to about 90 (until the fan kicks in).

What could be the case? Thermostat is just new and did not help...

For future reference

[1975DCS]

For future reference

That is fantastic! How on earth did you ever found that out?
Do you have these for the others as well? I would never expect the scale to be this divided. Why do you want to know the difference between 88 and 90 degrees?

Ps. which engine part would be the best to measure under the bonnet?

[Jamo]

The search button is a wonderful thing infact your sympthons have been covered on the forum a multitide of times.

Look for post from AAH and Ross for example.

[1975DCS]

Yes I know... But in this case the sensor and thermostat are brand new... And the sensor does seem to have some sort of (black) isolation...

But otherwise it does seem to reach the second notch and now I understand why this take so long as from 50 to 85 degrees is big step... And if it quickly rises to the 3rd or 4th notch on indling I can understand that as well as this is only 1 to 2 degrees difference. And a misreading of a sensor or gauge can easily reach to a few degrees in difference...

[newsh]

The black isolation you mention is the original rubber boot. Mine was split so I removed it and replaced with some water hose, according to the calibrated gauge from Jamo mine sits at about 87 during cold weather driving.