The MGF Register Forums

hi all, the TF no longer gets warm on a drive, unless I put it under load or get stuck in traffic.. basically, 5-10 miles now before I get much heat inside, and before the gauge gets to 'normal'

This is a partially stuck-open PRT thermostat I think?
just had a look underneath after a couple of mins running, and one of the front to back pipes (nearside) was warm despite the temp gauge being 1/4, the other pipe was starting to get warm..

Car used to heat up fine, but has been sat for a while.

If so, is it possible to block the three thermostat pipes and change without dropping the coolant? and then bleed.. only reason is the coolant is quite new..

many thanks
John

That all sounds normal to me. the TF, in essence has 2 coolant systems, one for the rad & one for the heater matrix. The heater matrix warms up before the radiator system from memory. If both pipes are warming up at the same time have you checked the radiator to see how that feels? Have you felt the pipes onto the heater matrix to make sure they're getting hot?

It may be something as simple as the heater controls needing adjustment. Have you got an obd reader to see what the temp is actually doing?

I changed my PRT they are cheap and its an easy swap, but I doubt you could block the hoses ...I just carefully caught it all in a nice clean bowl, filtered it and put it back in.....

Yeah, what Gedge says although did the problem happen as a result of the fluid change?

thanks all.

I did a headgasket about 10K ago, and 3 years.. I did try to flush the system at the time and there does seem to be rad flow .. The car always heated up quickly, both the gauge and the matrix.. but now neither heats up unless you are stationary. I bought a new thermostat anyway and will change it (as I didnt when I rebuilt the engine)

John

Hi all. I finally changed the stat yesterday and bought some new coolant. What was interesting was the rubber seal in the stat was broken and was no longer sealing that well . I can't test the car as it's sorned, but went through all the bleeding and got her warm enough for the new stat to open.. all seems ok. Have a pic of the old stat and will post it when I can

John