What tempreture should my RS2 run at?

[s2_bo]

Should an ADU engine run at the same temperature as the 3B and ABY?

Im only seeing around 70c on the rs2 during motor way driving and up to 90 in traffic.

I have tried bleeding the system a few times by running the car hot, then waiting for it to cool down a bit, opening the bleed screw and lifting the water reservoir up a bit till water flows evenly out of the rad with out bubbles.
I then replaced the screw and lowered the reservoir back down, did the same on the heater matrix hose.

Is this a correct way to bleed the system? Or should i only do it by running the car up to temperature and waiting for the fan to kick in 3 times while topping up the water reservoir?

Finlay the thermostat is stuck open then would that course it to run cool at around 70c?


Im driving to france for a couple of weeks on tuesday so would like to get it right beforehand as not to damage anything.
Also the blowers are not blowing very hot air even when set to max temp and its very cold over there so it would make sense to get it fixed.

Is the RS2 thermostat the same as the S2 one? I havent got any way of checking atm...

Thanks.

[A80Avant]

it is normal to see highway driving temps at 70C because the reading comes from the 3pin connector which is located in the water bridge under the inlet manifold.It has been said before that the temp is correct that way and represents the temp after the cold air has cooled off the water due to high speed running.On newer audis it happens the same but the reading never goes lower than 90C because it is set this way.

Our sensor is more accurate and it reads excactly what it sees.You could read off the A/C reading(if you have climate control) the radiator temp sensor.Finally through vagcom you can read the engine block temp sensor which is what the ECU sees.Sometimes all 3 sensors do not aggree,but basically the reading on the dash and the radiator sensor should read pretty much the same,and the engine sensor maybe slightly more.

The thermostat on the RS2 is normaly set at 87C to open.You can check if it is working by starting the car from cold,wait until the reading in the dash starts to become close to 90 then touch with your hand the hose that leaves the thermostat(lower from the 2 hoses between the small radiator(aux) and in front of the A/C condenser.Originally this hose should be cold while the top hose is already hot as the engine is working.As soon as the thermostat opens,the hose starts to warm up.Thats when you can see from the dash when the thermostat actually opens up and if it is stuck.

If it is stuck open,you would feel the hose warm up very fast,same as the top hose so that means your engine fails to reach the 90C of operating water temperature.If it remains cold it means that the thermostat is stuck closed,but then you would see the temperature go high up,especially in small traffic.

When running on the highway,the engine gets very cold anyway,and the radiator fans or thermostat basically stay shut.

[iain1067]

IME it should sit at around 90 degs, if the temp is dropping off on the motorway then i would suspect the thermostat especially as the heater isn't great either, does the heater improve in town??? as far as i can tell it's the same part 069 121 113 87 deg c thermostat

[s2_bo]

Thank you guys!

Thats a big help, i will test the thermostat via the hoses later on.

What channel should the climate control be set to to read the radiator temp sensor?

[Rusty]

Thermostat is a £10 part and a PITA to fit with all the plastic cowling for the rad. It's either the stat or you have a leak.

[s2_bo]

There is a very small water leak but i haven't tracked it down yet. Would that cause it to run cool?

[A80Avant]

channel 51 it is
i have a radiator sensor to start the fan @ 85C so it monitors that perfectly so far.also i changed my thermostat to an 80C rather than 87C.nice and cool

[Rusty]

You don't want it too cool. Sub 80 (I think) puts the ECU into warmup mode so the fuelleing can be enriched. For Greece I agree this was a needed mod but perhaps not so essential for N-o-T

[A80Avant]

i told erdal about those changes so he modified that as well so it would not go into the rich mode.He also agreed that the cooler the better for the engine.All those high temps are the cause for cyl.head cracks and wear.

[Jamo]

Are you sure you seeing 70c?

[s2_bo]

Now i feel really stupid...

Thanks Jamo.
Turns out im seeing about 87c.



That saves me a job anyway..

[merlin's S4]

Don't worry Bo, I didn't realise that either! Thanks Jamo!

[A80Avant]

yup,had forgotten about that pic myself!

[Jamo]

Ah I love my party trick hehe

[Rusty]

Normal operating temperature should be 1 to 2 notches below the 90, fan cuts in at 1 notch over 90. If it's different to this on an average day then the stat is tired or you have a leak, in the sub 0 temps at the mo I'd not worry yoo much. If you're running an aux. rad then maybe cover it with some card to stop it running too cold, loads of us run with no aux. rad so you'll not do any harm.

From that pic I've seen about 110 at Combe in '07!