dont get me wrong, ive used the search and read atleast 100 overheating threads. but my car has me stumped. it just overheats after 10-15 minutes of driving. some time it the needle will slowly rise, but then just drop back down to normal. then slowly climb again.its got a d15b7 d16z6 mini me, i had a 93 and it worked amazing never had any problem, especially with overheating. but then i got a 94 in way better shape then my but needed a head, so i just put my motor in it. ever since then its overheating, its my rad, ive checked it for leaks, along with everything else im about to say, my over flow tank, brand new cap an rad cap, my hoses, new hose clamps. i didnt touch water pump or thermostat. ive got my fan wired to a switch. im going to replace my thermostat with another one i got tomorrow an see what that does. oh yeah and its already got a bottle of some stop leak stuff

 

just change out that thermostat and gasket and see what happens that is probably the reason if not check the hose right under neath the distributor

 

Flush out the stop leak and bleed the cooling system.

 

ok so, the thermostat can not be removed, after my best attemps the top bolt broke off in the thermostat, and i dont want to risk breaking the other one off until the motors out, but i flushed it an bled it and it seems to be better. now it seems like its messing with me, the temp gauge will wrap past hot, i drop it in 3rd an hold it the temp drops to normal almost instantly, and if its wrapped, and i turn it off then turn the key forward right after, the gauge reads normal, sometimes below. but the water in the overflow boils everytime.

 

Realize that the thermostat is where the lower hose meets the engine. Not the upper like is typical on American cars.

Start the engine cold with the radiator cap off, if a bunch of stuff bubbles out when you rev it it's a blown head gasket.

 

the one the lower hose meets is the one with the broken bolt. I was thinking that, when it first starts it spits water up and when the bleeder screw is out it is constant bubbles. no oil or anything though

 

took the head off, HG was wrecked. not sure if its going to fix the overheating but i will post later. and i wish i had a camera to show the world what a disgusting mess any kind of block sealent makes, water passages completley clogged left right an center, after i put half of the smallest bottle in the store.

 

Ouch, sorry to hear it was the head gasket.

 

Yea, all that stop leak and repair in bottle stuff can do wonders clogging up little leaks etc sometimes, but usually 100% of the time it does a great job clogging up the small passage ways within the coolant system.

 

thanks for the input guys seems to be fixed. and yes a couple of the passages up threw the block into the head were completely sealed over, with 1/8 thick plug of junk.