drshottest718

I know this has been discussed before but maybe i can get a little personal insight on my specific problem.

I bought a 1994 4dr civic. The previous owner told me he replaced the t-stat because the car used to overheat, he also told me the car had been sitting for 3mos. So on the drive home (25min drive) I didnt notice the car overheating at all but i smelled coolant. When i get home i noticed the rad cap was leaking coolant and steaming. I let the car cool down, open it and see the cap is garbage. I replaced the rad cap and i thought that would be the end of my problems.

15mins later while idling i see the cars overheating again and the radiator is steaming. There is NO LEAKS now but it seems coolant is oddly enough, just slowly coming out through the rad fins. No specific location just seems the radiator was moist with coolant on the outside which was causing steam and whatnot. The rad fan has YET to turn on as well. Even when idling for 20mins or so and when the needle went almost to H NOTHING. I'm hesitant to "jump" the fan because i've heard this is not exactly necessary and kind of ghetto lol. I checked the inside of the radiator and it had some weird green 'gunk' built up inside of it. I scooped some up with a key and it smelled like old coolant build up. Also note that the reservoir for the radiator was empty. Even after refilling it though, it still was overheating.

I have a spare radiator on the side that i was going to swap in to see if the radiator is just old and busted. Could it be just the fan? or is the radiator more likely to be the problem.

Former User

Swap in the good radiator, bleed the cooling system, and go from there.

B16Drag

Just short the plug that goes to the temperature sensor for the fan. Its right by the thermostat and is a two female connectors. I just put a lil paper clip into and the fan turns on ONLY when my car is on and turns off when its off.

No more over heating issues for me and the fan turns on everytime now! hah

jooky5

If your radiator has a leak then it wont build much pressure.. thereby lowering the boiling point back to 220.. which wont turn the fan on at that temp .. Fix your leaks.

You mentioned the temp almost got to H.. I would expect the fan to kick in by then.

A stock engine doesn't use the fan.. well, only in a traffic jam stop and go.. no airflow type of driving.

drshottest718

leave a paper clip in the pin?

B16Drag

Yup. But if there is radiator fluid coming out through the fins, I think you might need to replace the radiator...

drshottest718

i have NO leaks. The only coolant i see is just kind of appearing all over the rad, as if it was just coming thru the seams.

drshottest718

I'm in the proccess of replacing my radiator now but i have no indoor garage and its raining. and WTF!!!?! those two hoses that come on the AT that plug into the bottom of the radiator are a SERIOUS pain in the ***. The little clamps with the screw are rusted to sh*t and the ones that are connected to the hardline are in there super tight.

RotaryPWR

i don't like the "fan always on" fix. it robs power (even if only a teeny tiny bit).

there are 3 things that can go wrong with the fan: the fuse, the switch, and the fan itself. ok, wiring would make 4, but it's unlikely it's that

easiest thing is to check the fuse. if it is toast, replace it. easy fix.

if not, jump the switch like B16Drag said. If the fan works, the switch is ur problem.

if neither of those is at fault, test the fan. i think u can either use a multimeter or actually link it to the battery with known good wiring and see if it turns on.

my bet is that the coolant on the fan is actually leaking from the reservoir tank when it overheats and boils over from the fan not working..but maybe not!!

drshottest718

Well i checked the fuse and that wasn't it.

Its raining so i'll have to wait till tomorrow to mess with wiring.

jooky5

That's a leak in my book.

B16Drag

I have to agree with jooky on this one.

angel_i

I'd flush the system, bleed it, and make sure the fan kicks on.

drshottest718

well thats why i'm replacing the radiator, i meant no leak from hoses, or the cap etc. lol

Former User

First replace the radiator and then bleed the cooling system before you worry about the fan. The fan may not be kicking on due to air allowed into the system by the radiator leak. Therefore, you actually may not have a fan problem after the radiator is fixed.

drshottest718

UGH! i had a 5spd radiator and therefore it wouldnt work because it doesnt have the two lines for the hoses that the AT uses.

I'm going to try and clean or flush out the old radiator see if that works.

angel_i

Autozone has the radiators that have the tranny lines on the bottom. They are $100 here and they are thicker than the 5 speed radiators.

drshottest718

I realized why my fan wasnt turning on, it was the fan switch. I connected a wire to the plug and it turned on, so i'm going to replace the fan switch tomorrow. Should that be the cause for my overheating?

BelZeBuB

I have the exact same symptoms on my 98' Civic DX right now, where the top tank seems to be boiling over because the fan is not running. I put my relay for the cooling fan in the A/C relay slot and it works to kick that fan on. I will have to try the ECT switch I hear is near the Thermostat housing to see, but I also noticed that a newer Rad costs 55 - 100 bucks which is not bad, and I may just replace the thermostat while I have it all apart, but after I filled new Rad fluid it seems to be running at an ok temp now, just need to fix the fan switch prob, and then I will work on the Rad itself if it continues to leak as such.

Speaking of which, until I do the Rad replace is this "Scotts Super Seal - Radiator Stop Leak and Rust Inhibitor" worth a shot to at least keep things going till I can do the whole shebang?

BelZeBuB

I am seriously worried about putting in some stop leak crap if it is going to gunk up everything else, but this leaky radiator by chance, since the end game result should be a full radiator replace anyway, but again, can anyone confirm if that will do anything bad?

BelZeBuB

Doing my best to just wait till I can replace the radiator on Friday, but the urge to tinker is burning me up right now until then. Although, the plain side of me tells the frosted side to just chill and do the Rad first.

asbloodrunsblak

this happened to me. i just jumped the temp sen. and bought an ebay special 3 row alum. rad. a good $50 investment.

DAforlife

yes that will solve the over heating problem if your overheating when idling if your driving down the road and it overheats thats a different issue

SKVGR

So you had a auto trans before you converted ? I want to know because I converted my 98 hatch cx to manual and my car now over heats and wanna know if I would have the same issue as you

Former User

Please create your own thread.