landon.alder

So my 1994 ej1 civic has been overheating quite a bit recently, mostly after being in traffic for a long period of time. Here's what I've done so far since I bought it 3 months ago:
-Replaced the radiator
-Replaced the thermostat (OEM)
-Replaced the thermo fan switch (OEM) & tested fan (it works)
-Drained & Refilled coolant

The only thing I can think of is the water pump, but this doesn't make much sense to me either because even at idle I can feel the coolant flowing and my engine doesn't seem to cool down any better when it's revving compared to idling.

Any ideas of what this could be?

Former User

If you unplug the fan switch and short the 2P connector with a jumper wire or paper clip, does the fan run when the key is turned to ON(II)? If so, bleed the cooling system:

Bleeding the cooling system may take 20-30 minutes.

1) Park the car on an inclined driveway with the front end higher than the rear.

2) Push the dash heater lever/**** to MAX heat.

3) Follow the directions in the diagram below (hint: the bleed bolt is located where the upper radiator hose connects to the engine):

landon.alder

I was running the radiator fan with it jumped for about a month and the radiator fan was working, but it didn't make much of a difference.

What I don't get is that I've tried to bleed the system quite a few times but it seems like the engine will never overheat no matter how long it idles in my driveway. I actually have to drive it someplace in order to get it to fully heat up.

Former User

Have you bled the system as described in my post above? If so, do you lose any coolant? Have you pressure tested the cooling system? Any gas bubbles in the coolant? Is the coolant discolored? Any white smoke in the exhaust?

landon.alder

There's no white smoke in the exhaust and the coolant isn't discolored. I haven't been losing coolant.

I've tried to bleed it a couple times and it does let air bubbles mixed w/ coolant out of the bleed screw, but after idling for a while, it gets to the point where nothing is coming out of the bleed screw.

I haven't pressure tested, but a lack of pressure would be caused by a bad rad cap right?

Former User

If everytime the cooling system is bled, you see some gas bubbles in the coolant, then a blown head gasket must be considered.

Or a cooling system leak elsewhere in the system.

JonBaillio

went through everything you have done and had the same issue. The culprit was a leak in the coolant hose that runs from right behind the water pump to the IACV. After that I noticed another leak that was from an improperly sealed thermostat housing (Gasket got pinched allowing fluid out).

To look for leaks put a drip pan or a large piece of cardboard under the car overnight. Then it is just a matter of working backwards to find the leak. Also don't ignore the heater core as a possible source of leaks.

good luck.

Jon

sxyalexxx

Same here, found a big hole in a hose squiring out all my coolant, hose replace, flush, and clean coming soon.

Anything suggested for yucky radiators besides cleaner? Or perhaps a certain thype of cleaner?

landon.alder

hmm, this isn't sounding good. Thanks for all the suggestions

This is starting to sound complicated enough to make it worth just paying for an hour of labor or so at a shop to get it diagnosed :/