bazaar overheating issues, HELP!!!!!
 

hey guys, ok here it is. 00 civic Si turbo. i started having overheating issues awhile back after turning up the boost. i had mixture of oil in the coolant resevor, so i replaced head gasket and replaced stock studs with ARP. problem went away, now its back. thought it was a bad radiator b/c i could see steam coming from it, so i bought a fluidyn and slimline fan. didn't fix it, so i replaced the thermostat. (2nd one in 4 months). still no beuno. guage will sit at normal untill i start driving it, then it goes up and seems to fluctuate with the RPMs. thought it was a bad temp sending sensor. so swaped with friends sensor, ran around the neigborhood for 20 mins everything was perfect! his temp gauge didn't work at all. thought it was fixed but then after letting cool and start home again car overheated again!!! the only thing is it will go to 100% hot, pin the needle. but car doesn't make any odd noises. runs fine. head isn't too hot.(can put hand on it) exhaust manifold isn't overly hot and hoses really are not too hot. doesn't seem like it is really overheating, but i don't want to risk a built engine on a guess! no leaks, no white smoke, heater still blows hot air. does someone have a clue on whats going on???? im out of ideas. sorry post is so long i just wanted to get everything in there.

Have you taken it to an experienced mechanic? It seems you've done and checked what most ppl would do as well. I hope you figure it out bc that really is bizarre. Bump for an answer that someone else might know that you missed.

look into evans npg+ coolants. when you replaced the head gasket, did you check the old head for warpage and get it resurfaced? overheating generally damages something, whether it be warp the head or ruin thermostat or something else. you need to find what caused the problem, not just repace gasket and have it come back again. check the engine compression first, look at the plugs, make sure the gasket isnt leaking again. you may be better off getting a new temp gauge and checking that instead of the stock one first before you go spending more money.

sounds like the water pump is seized...if u havent checkd that yet...same thing happened to my friends 2000 ek turbo single cam

thanks
 

ok, the reason the gasket blew was stock head studs are only good for about 300hp. i didn't resurface it b/c i caught it early. probably should have. yes he is an experienced machanic. i've talked to a couple other friends that own racing shops, and im going to change out thermostats again with a nicer one. not from autozone. and make sure i don't have any air bubbles in the waterneck. i will also get a laser temp reader and point it at a few spots on the engine. if its only hot behind the waterneck i will know its a bad thermo. i will do a compression and leak down tomorrow and see what i find out. thanks for all the info guys. ill let you know what i find out.

you know how to bleed the cooling system right? you gotta remove rad cap with car cold, then start car and warm it up to temp, then blast heater and wait for all the air to come up out of the heater core. it could take a while, and if you have a gasket leak, the bubbles will never go away and you will lose coolant over time too.