White_951

Well I did a test and tune yesterday at PBIR...overall results are excellent, pretty much what my goals were....breathability at mid to high RPM is outstanding. But the car is now running just a tick above the halfway point on the temp gauge after just a few laps, this wasn't the case with the 26/8.....

Normal street driving is as usual, a tick above the first white line, but while waiting for a train to pass on the way to the track the car went way hot also...

Radiator burped fine on re-assembly, 2 1/4 gallons. Fans working fine. Turbo water pump gushing into reservoir, AFR's are great and belt tension is right on... Water pump maybe????

951kaos

Had a similar problem after replacing timing belt/waterpumps/rollers/seals/thermostat/hoses recently. Car would heat up more than before while under long boost conditions or waiting for a traffic light. Replaced the main thermostat as others on this forum had defective new ones; it was replaced and helped a bit as it was opening about 90% compared to another new one. The only thing left on the cooling system that was not touched at the belt service was the pressure cap on the expansion tank (cap and expansion tank were replaced 3 years ago) and radiator. Took the cheaper of the two to narrow the problem further and replaced the pressure cap with a new one and all is well. You might want to pressure test the cooling system for leaks or a cracked expansion tank and check the pressure cap.

Tom M'Guinn

Are you sure you got all the air out of the system? When you turn on the heater, do you hear gurgling? If so, there is still air in there... With the car moving above 25-30mph, my car stays near the first white line (3 liter, VR5 turbo) with stock radiator, pump, etc. In stock and go traffic it can creap up and down a bit...

xsboost90

sounds like you need to bleed the system some more. My K27/8 would run with temps in the middle on a hot day at the track doing an hour at a time...

White_951

Thanks for your responses...I'll report back after I've performed these....

tjbreen

Are you running with or without the undertrays? I have similar issues with my bigger turbo but live in New England, where exess heat is rarely a problem. I noticed it this year though at Watkins Glen when the ambient temps were unusually high (100+). Car ran hot enough that I had to cut my runs short to prevent overheating. Other 944Ts in the paddock had no issues.

White_951

Yep, undertrays intact, but batwing removed for splitter.....

Overheating at the train crossing concern's me and leads me to believe I may not have burped it all the way, although Clark's says capacity is 2 1/4 gal...and Saturday was the coolest day in months down here...~85....the small turbo ran fine all summer @ ~100....

BTW, I have bypassed my heater, not necessary down here...

White_951

Got home tonight and got the car up to operating temps, came back and let it idle for more than five minutes....car stayed rock solid just above the first white line on the gauge...

On the other hand I've determined that the turbo cooling pump is inoperable...no switched power to the pump...