i got a 96 turbo hatch with a d16y7/14b turbo. when i cruise and gun it every once in a while the temp would still be fine. but if i put alot of stress on the motor like high revs/boosting repeatedly like on the freeway pushing the car alot it would overheat. no milky bullshit in the oil. the car still runs the same. vacuum is still the same at -20 - (-21). alot of people say its the thermostat, so i'm gonna change that but would it cause my coolant to run low/dissapear?

 

u running a half radiator? or full size with 1 fan?

 

half rad and the fan still works fine. it recently happen about a week ago and car was boosted for more then 3-4 months

 

Try the stat. The half radiator/fan should be just fine.

 

I had the same problem and it was the headgsaket, hmm but my coolant bottle was overflowing though. I guess try the thermostat first or a new rad cap and see if that helps.

 

I had the exact same problem, same setup on a z6. Found the radiator had a pin hole which leaked very little when boosted hard.

 

Headgasket on mine. Not enough to make it noticable. Just enough to over heat.

I tried everything before that. BRAND NEW Full-Width Dual core rad, Lower T-Stat, Water WEtter,

Ended up being the HeadGasket.

 

My overflow overflowed. It was my water pump.

I still replaced the t-stat and radiator cap for good measure. Also flushed the system and made sure I had the right ratio of coolant in there.

Set your heater to HOT and fan on HIGH, start the car with the rad. cap off and wait for the t-stat to pop. Burp the air bubbles and add coolant. Keep the engine revved to 1,500 because this can take a long time.

If that still doesn't work, all that's left is radiator or headgasket... I was a long holdout with the 1/2 size single core, but it gave out a day before a big race. A double core DelSol radiator will cost you $105 at Napa. Good investment.

My car's been pretty cool ever since. I won a free Cometic head gasket & have had some ARPs sitting around forever. Those are going in this winter.