Do I need a new thermostat??

[nick9one1]

I know the TFSi takes a little while longer than your average engine to warm up... something to do with the direct injection I think..

But I've noticed mine is only getting close to 90 after a 40 min drive on A roads (my daily commute).
In fact, the needle never gets quite to 90 and always sits where it is on the pic below ..

I went a little further and fired up Torque, created a dial for coolant temp and strangely it only thinks the engine is at 77!

So then I popped the bonnet and felt to see if the main water pipe to the rad was hot.. it was. So thermostat is open.

Do I need a new one?
Is there two thermostats on the TFSI?

 

[Alex_Dubz]

I guess is usual on that weather mate. Same happens to my gf's Passat when driving out of town, about 70C on a long road, but in city traffic it stays on 90C. That's why some people put cardboard on the front grill during the winter (don't know if they do that in the UK but they do it here )

 

[nick9one1]

Thanks for the reply.
Good idea about the cardboard!
You could be right.. although shouldnt the thermostat only open at 87?
if torque is saying its 77.. its opening early?

 

[OVRA3]

It's stuck open trust me just had the same thing with mine. Thermostat problem is really common after 4plus years.

 

[nick9one1]

Thanks.. I'll change it then

I can see two on ECP.. one opens at 105 and the other at 87

So does the TFSIi have two?

 

[OVRA3]

The one you want is the cheaper one. I've got a tfsi 2005 axx engine and that's the one you need

 

[nick9one1]

perfect, thanks!

bargain with 20% off!
thermostat and coolant delivered for £33

 

[OVRA3]

Thanks for that just ordered myself 4 new plugs and a new coil pack for 52 quid! Nice work. Fingers crossed it sorts out my misfire!

 

[Greeny233]

Don't use cardboard to block the grille off, if (when) it gets wet it will turn to mush and Block the cooling fins on the radiator. Try and get a piece of plastic. I know this from personnel experience, took ages to get rid of the mush from the rad.

 

[nick9one1]

OK, Ive fitted the stat.. what a job! Took me two hours.

It has improved things.. the in car dial now gets higher.

but, when I'm looking at the temp through Torque its still much lower (75-80).
From what I've read there are two temp sensors.. one for the ECU in the engine block. And one for the gauge in the radiator. Can anyone tell me if this is correct?

 

[nick9one1]

I've changed the temp sensor too and its not made any difference..

25 min drive into work this morning and the car still wasn't up to temp

Can anyone tell me for certain if there is only one temp sensor and one thermostat on the TFSI?

 

[Staz]

You really need to get it on VCDS to see what's going on mate.

 

[nick9one1]

I've got it on VCDS and the temp is the same as the "Torque" screen shots I've posted. No fault codes.

So basically..

1 new thermostat, one new temp sensor (right side of block - 2 wire)

Dash is indicating the temp isn't getting to 90. Torque/VCDS confirms this, but tells me its actually about 5-10 degrees lower then whats indicated on the dash.

 

[Staz]

Did you use the measuring blocks part to check the temps for the different sensors? I don't know what Torque can tell you (can't see the screenshots in work anyway) but I'm having similar problems, my DIS outside temp is showing a high reading. Through VCDS I have narrowed it down to two different sensors. Perhaps you'd be able to do the same.

Other than that I can't really help. But in 5-6 years with the 2.0TFSI (A3 then S3) mine engine temp has always managed to get up to 90oC, even in the depths of a German winter.

 

[nick9one1]

Thanks for the reply!

I'm talking about two sensors in the cooling system (if there are actually two!).
If your DIS is high, isn't that to do with ambient air temp?

I've only looked at one sensor using VCDS, but on the way home tonight I'll see if I can find another and log both sensors over the 30min~ journey.

 

[Staz]

Thanks for the reply!

I'm talking about two sensors in the cooling system (if there are actually two!).
If your DIS is high, isn't that to do with ambient air temp?

I've only looked at one sensor using VCDS, but on the way home tonight I'll see if I can find another and log both sensors over the 30min~ journey.

Yes my fault is different but I was using it as an example of how I found the issue using VCDS. Not faults were logged BTW.