05CivicProblems

like the title and my username says...

I got some questions pertaining to that overheating issue I am having with my wifes Civic, and I've run out of ideas here. So, the car has overheated at three different times, starting last summer. Each time it overheats, I replace the thermostat, flush the system and try some combination of parts. Each time, I've replaced more parts of the cooling system, this is what's been done:
fresh coolant
both radiator hoses
radiator
radiator cap
thermostat/o-ring grommet
engine coolant temp sensor
radiator fan switch
have all been replaced. The fans cycle exactly as they should, so the motors and relays there are good too. The system has been bled countless times (as in, let the fans cycle twice with radiator cap off since there is no bleed nipple). Tonight when it overheated right as my wife was pulling into the driveway, she called me and I came down to check it myself. The fans were even cycling like normal while the gauge kept climbing. I'd think maybe the gauge is the problem, but 3 months ago when it last overheated the gauge spiked then the radiator blew a 12" crack 5 seconds later so it's def a real problem.

Every time it overheats and I take it apart to fix it, it runs just fine for a few months then starts overheating after being driven more than a few hours at a time. I'm completely baffled, I can't find a problem that isn't consistent, and I'm borderline ready to just fix it well enough and sell it. Do you have any ideas? The fans even cycle while the temp gauge climbs, so the system is working exactly as it should. I also checked the coolant level and there's no missing coolant or bubbling in the radiator neck, and beyond that, if it was a headgasket, it would be a consistent problem, so I'm very sure its not a blown headgasket superheating the coolant.

This may or may not be important, but in all of the 3 cases that it has overheated, it was driven for multiple hours beforehand on light freeway traffic which turned to stop and go traffic. And when I say overheated, I mean the needle almost getting to the red (or, of course, the radiator blowing up instead)

If ya got any ideas, I'd love to hear 'em. I'm tired and done throwing guesses, money and time at a problem that isn't consistent.

Thanks all!

toyomatt84

iTrader: (1)

How many miles are on the car, and have you ever replaced the water pump?

05CivicProblems

It's got 160k roughly and the water pump was done 60k or so ago. If it wasn't circulating water due to the impeller on it slipping or wearing, I could replace it, but if every time it overheats and I do some flushing nad replacing of parts and the car runs fine for 3 months at a time, wouldn't that kinda rule out the water pump? I'd think it would just overheat right away again.

holmesnmanny

rule out the head gasket with a compression test after the car has warmed up fully

be sure to disconnect the coils and the fuel injectors or you can pull the relays

05CivicProblems

Appreciate it but a compression test wouldn't distingush a HG problem from a bad valve spring. I'll do a leakdown tomorrow because at this point the consistency of it running fine and then overheating every 3 months for until I pull apart the whole cooling system and throw parts at it is making me think a tiny, tiny crack in the HG is building up air and pressure over time.

I don't understand how else the car can run fine for so long. If there was a real problem with any work I did to repair the cooling issues, it wouldn't have lasted 6000 miles each time

JPat

He mustve meant a cooling system pressure leakdown test

My girlfriends d17 was doing the same thing, we replaced the same with the same results.

It took a year and a half before i finaly took the headgasket out and it fixed it. She over heated that car big time 3 times and the head survived

Ive had an 05 El, and 5 different civicis and SIs and had the head gasketts changed on all. Oh and my 99 1.6 too