I am running methanol on stock turbo at 28 psi arounding about 380whp. The car was backfireing for the past month. After running hard with couple of back fire the car has been overheating ever since. I do not have check engine light and seems to run fine for 10 minutes but over heats and smoke in engine.

What is possible reason for this? I hoping bad spark plugs.

 

Head gasket? What are your air fuel ratios? If it was back firing alot thats not really a good sign imo.

 

If you drive the car gently, no boost, does it ever overheat? If it only overheats when you boost, you might have a blown headgasket. Do some research on this, or take it to your mechanic before it gets worse. Have you checked the coolant and oil levels? Plug change is a good idea too.

 

First off, how many miles on the car? Any coolant leaks? Does you car seem to have a loss in power?

 

sounds like head gasket.. or thermostat

 

Im thinking Thermostat, but we need more info. They are cheap enough to replace to weed out the possibility of that being the problem. I'm pretty sure he would notice a blown gasket by how it runs.

 

when you take the oil cap off does it have a milky residue on the cap?

 

I do not think it is thermostate because I see smoke coming out once the I open the oil cap. Also my car currently has 40k on it.

Under normal driving it seems fine for 10 minutes then it over heats.

 

Normal as in boosting or no boosting? If its overheating w/o boosting, then I would suspect headgasket. do not drive it more than you have to, or you risk blowing your whole engine. Is the under side of the oil cap milky? Dip stick? How's the coolant level?

 

i also have the same problem. Its been 3k miles since i got my car rebuild. I leaks coolant at wot. Immeadiately after a wot pull, it starts to overheat if the car at idle, if i strat driving it again then the temp goes down dramtically. If driving while not boosting, it would not overheat. I've also let the car running for an hour and no overheating. Please help me out!!!

 

op sounds like he's got a bhg, also this is stupid, but check to make sure your fan is comming on.

 

Did you log the coolant temp? My car typically warms to exactly 197°F then thermo opens and fan spins (slow speed) until about 187°F then it warms up again.

 

I had the exact same problem as you and it was the most awkward thing. After building my motor, the car worked fine but my A/C compressor suddenly broke causing the belt to overheat and break. We put in a rebuilt compressor from a Mitsu SUV that was identical except for the pulley that was bigger. So we got a longer belt and it worked great except that when I started to rev the engine and give it some boost it would overheat. As soon as I let the throttle off it will immediately go back to normal. Just as you, I could keep the motor running for hours at idle and perfect, but once gassing it it would overheat. Whe checked the radiator, thermostat, head gasket, etc... and nothing. It turned out that the belt was about half inch long, eventhough it looked fine and tension looked perfect. But once the motor started reving the belt would start slipping causing the water pump to stop pumping. We put a new belt half an inch shorter and now the car runs perfect and is back to normal. I donīt know if you changed the belt but if you did check that the size was the proper one. Good luck

 

So i should look over the ac compressor belt?

 

There is only one belt that moves everything. This is why in my case is was messing up with the water pump. Just ask you mechanic if he changed if for a different one. Check if it looks in good shape.