My 53 VRS struggles to get to normal operating temperature.

 

I can do a 60 mile mainly motorway run and it'll not go above 70 degrees (measured by Torque Pro)

 

Additionally the fuel consumption has worsened too. I used to get 60mpg on the above mentioned run but now only get 50.

 

I may have a boost leak as there seems to be a bit more smoke at lower revs.

 

I checked the thermostat recently and it appears to be working OK.

 

What should I change first?

New thermostat?

Coolant sensor?

Anything else.

 

Thanks in advance.

If the gauge is only showing 70C, that's strongly diagnostic of a problem with the CTS. More so if the heater works correctly (suggests that the coolant is actually getting up to temperature).

 

I'd suggest confirming with VCDS, and if it is the CTS get a genuine one.

Did you check the thermostat by removing it and dropping it in boiling water, did you watch it open?

Did you check the thermostat by removing it and dropping it in boiling water, did you watch it open?

I did but I suppose it could be opening too early.

I did but I suppose it could be opening too early.

 

Nah, replace the CTS.

Did you check the thermostat by removing it and dropping it in boiling water, did you watch it open?

 

 

I did but I suppose it could be opening too early.

That is not how you check a thermostat!!

 

Put it in a pan of COLD water with a thermometer, and then heat the water. Now observe the temperature when the stat starts to open, and when it is fully open, and compare with specifications.

New CTS fitted and problem is still there, so genuine thermostat next.

So what is the normal operating temperature your oil gets to after 10 miles, and then 20 miles?  Do you have a reading for that?

So what is the normal operating temperature your oil gets to after 10 miles, and then 20 miles?  Do you have a reading for that?

I don't have a way of measuring oil temperature.

Is it available in the paid for version of Torque Pro?

Change stat.

I recently changed the thermostat on mine as it was running at 72c max, changing the thermostat fix the problem.

 

Out of interest I put the old thermostat in a saucepan of cold water and heated it up, using a digital thermometer I monitor the temp and the thermostat open and closed as it should (open at 87c), it has confused things a bit as I was expecting it to open early or get stuck but it did not, still not a big issue as the new thermostat has fixed the problem and the engine temp is now around 90c.

 

Had I taken the thermostat out to check it I would have been fooled into thinking it was ok when in fact it was faulty!

Changed mine in the week . Sits bang on 90 degs and now it's like a furnace in the cabin .. My temp used to get to about 80degrees then fall back to 60 ish . New genuine stat cured it .. Relatively a simple job ..

Regards Tony