Diesel Auto inline thermostat overheating

Don.Hasi · 20th April 2017, 10:00

I have read many topics but couldn't find one which describes my problem. So here it is:

My Diesel was way too cool. In the winter the coolant gauge didn't climb over the first quarter. So I installed the inline thermostat from Dmgr. Voila, cabin was toasty, mpg improved, more power and we had a happy driver with the indicator just a width of itself under half of the gauge

Now, with temperatures rising (yes, they do

) and giving it more load on the autobahn and/or with just little climbing, the gauge rises to 3rd quarter and there is, where the drama begins... If it is just under the 3rd mark, the car rolls fine, if it passes the mark, the ignition retards andthe engine slows down to limp mode

The power will come back, when the temperatures goes back, it goes downhill or, when I push the throttle to kick down and force more psi through the turbo. It feels like, the coolant flow is some kind of blocked, then forced to get open and presto, the needle goes back to half and the power is there.

The car has got just a fresh service with oils, filters incl Pcv, vitons, samco intercooler tubes and a quick clean of the EGR (which should be deleted next time, because the was many gunk found). It has warm start issues which are a little bit improved with injector cleaners, but no good at all.

So, what do you think? Is the inline thermostat not capable continuously autobahn speeds? Another fault to be checked?

Thanks for your help in advance.

20th April 2017, 10:00	#1
Don.Hasi Regular poster 75 Saloon CDTi Auto Join Date: Jan 2016 Location: Karlsruhe Posts: 75 Thanks: 49 Thanked 2 Times in 2 Posts	Diesel Auto inline thermostat overheating I have read many topics but couldn't find one which describes my problem. So here it is: My Diesel was way too cool. In the winter the coolant gauge didn't climb over the first quarter. So I installed the inline thermostat from Dmgr. Voila, cabin was toasty, mpg improved, more power and we had a happy driver with the indicator just a width of itself under half of the gauge Now, with temperatures rising (yes, they do ) and giving it more load on the autobahn and/or with just little climbing, the gauge rises to 3rd quarter and there is, where the drama begins... If it is just under the 3rd mark, the car rolls fine, if it passes the mark, the ignition retards andthe engine slows down to limp mode The power will come back, when the temperatures goes back, it goes downhill or, when I push the throttle to kick down and force more psi through the turbo. It feels like, the coolant flow is some kind of blocked, then forced to get open and presto, the needle goes back to half and the power is there. The car has got just a fresh service with oils, filters incl Pcv, vitons, samco intercooler tubes and a quick clean of the EGR (which should be deleted next time, because the was many gunk found). It has warm start issues which are a little bit improved with injector cleaners, but no good at all. So, what do you think? Is the inline thermostat not capable continuously autobahn speeds? Another fault to be checked? Thanks for your help in advance.