A couple weeks ago my 87 N/A started overheating real bad on my drive home from work. I found a small crack in one of the vanes of my fluidyne radiator which appeared to be where the coolant was coming from. I nursed the car home, pulled the radiator, and sent it back to be warrantied since it was just under a year old... while i was waiting for it back, i took the stock radiator out of my TII(in need of j-spec) and put it in the N/A. It seemed to work fine at first, but after 20mins of driving, the heat was ice cold and the temp ga was rising. i pulled over and checked under the car, no leaks, under the hood all i could here was massive bubbling(and yes i bled the cooling system) coming from the whole engine it seemed. i opened the relief valve and it blew out a ton of steam so i figured i just had some air still in there somehow. Drove it home, let it finish bubbling then topped off the coolant. the next morning it stayed perfectly cool on the 30min drive to work, but when i left work, it started heating up real bad again, still, no loss of coolant. i bled the steam again and it stayed cool most the way home then got real hot again. my fluidyne came back , so i put it in, hoping it was a clogged radiator or somethin, but fired it up and it did somethin kinda weird... it overheated very quickly again, but the radiator was still COLD as well as the intake and heater return line(and no heat was coming from the heater). the upper radiator hose was pumped up rock hard and the bottom hose seemed relatively soft... i figured my block must be clogged or somethin, so i first tried taking out the thermostat incase it was sticking, with it completely out, it stayed nice and cool, heater blew heat, and i drove it here to work today like that. its mostly highway so it worked great with no stat, barely even got warm. im gonna try a different stat tonight, hopefully the otherone is jsut junk, but it is only a couple months old! 2mths ago i replaced the waterpump, stat, all gaskets and pullys. What scares me is everytime i start it up now, i get a puff of smoke from the pipes and it takes a sec to idle smooth. it doesnt smoke after its started, and it still has great power... sorry this post is so long, just trying to be detailed. If anyone has any advice or solutions for me, PLEASE let me know, I'm baffled. one other thing, its seems to be flooding pretty regularly now, and it never did once before the initial overheat that started all this...



Thanks again!

Jeff

 

your radiator cap could be bad, also you might want to change your tstat



mike

 

i've been having the same problem with my coolin system, i replaced everything, from the t-stat, rad cap, rad, water pump, clutch fan, and i flushed the system, car still voerheated, i broke down and went to mazda, and they couldn't figure out what was wrong, only thing the told me is that i have a blown coolant or exhaust seal inside the engine, which is allowing exhaust to run throught the coolant, and heating it up real fast, ehnce y i replaced everything and it still overheats. so unfortunatly, i'm saving up to replace my engine now...with another or v-8,v-6, somehing just to have my car running. hope this helpes, hopefully u don't have the same problem i do