ccauthe

I apologize in advance for how long this may be, but I want to give you all as much information as possible so that we can hopefully get this figured out.

My car ('93 accord) is overheating. Due to an accident several years ago, I don't have a reservoir for my coolant, just the radiator. When it first overheated, I added 50/50 water & antifreeze directly to the radiator. That did nothing, and I noticed that my radiator fan would not come on. So I began troubleshooting:

1.) I checked the fuse for continuity
2.) I tested the relay, by switching it out with another one.
3.) I hardwired the fan to the battery and it came on (so the fan motor is fine).
4.) I jumped/bypassed the thermoswitch using a paperclip and the fans ran continuously. However, I left the paperclip in so that the fans ran constantly and the car still overheated. So, while the thermoswitch (or other electric component upstream) may be bad, apparently even with the fans on it is overheating.
5.) I then removed the thermostat and tested it-- it opened fine as expected because my top radiator hose gets hot quickly as it should).

Now I am at a loss and hoping that your expertise will help me! To summarize:

I believe the water pump is working because my top radiator hose gets hot when the car is running (meaning that fluid is heating up in the engine, the thermoswitch is opening, and the hot fluid is cycling back to the radiator through the top hose). Also, the heat in the car is pretty hot. Although there is a problem that my radiator fan is not coming on, even with the fans on the car still overheats, so there must be some other problem. But if I have enough fluid (which i do) and it is cycling properly through the engine and radiator (as it appears to be) and the fans are on cooling the radiator, what else could be wrong?

(My fear is that I've blown a head gasket and gases have been released into system and that's causing it, but I'm hoping not).

Thanks so much for taking time to help me out! sorry again for the length of the post!

jdmh22eg2

try running w/o a thermostat

compression test motor

report back

ccauthe

Okay I will. A lot of coolant came out when I took the thermostat out- should I put more water in the radiator or just leave it?

jdmh22eg2

refill with what ever you got coolant/water. also make sure your fan is working while its out and drive around town (close to home)

you might also have a air pocket in cooling system. after removing thermo find a incline (so top half of radiator is higher angle than engine and refill and watch rad till its full.

grjr

You don't have a reservoir, what do you have the line coming off the neck of your radiator plumbed to? Without a reservoir you're going to be losing coolant from that line. I'm guessing you've already gotten under the car with a flashlight and looked around for coolant leaks under the radiator, water pump, radiator hoses, heater hoses, coolant bypass hoses and all their connections?

holmesnmanny

seriously, don't put anything but distilled water / 50/50 coolant / pure coolant into your system...preferably 50/50 coolant like you're supposed to have.

If you put tap water you're going to be screwing your cooling system components and/or engine itself.

ccauthe

Thanks everyone! I should have some time to work on it this weekend, so I'll keep you updated.

grjr - I don't have the any tubing coming off the radiator neck, so I do lose small amounts of coolant there, but it's been this way for 4 years (4 hot summers) and I've never had a problem.

As far as checking for leaks, I can do a more thorough check, but when it was overheating I stopped, let it cool down then took off the radiator cap and the radiator was full of coolant-- could a leak still be a concern?

subman20

make sure the thermostat is in the right way and the pin is at the top fill radiator keep cap off start car turn on heat full blast let run tell all air bubble are out of hoses and radiator if car still over heat could be water pump or head gasket

ccauthe

Okay jdmh,

I was going to do the compression test today, but when I took the spark plug wires off, the spark plug well/hole had a lot of oil in it. Like an idiot (and against my better judgement) I then proceeded to remove the spark plug, letting all that oil drain down into the engine. I stopped there. Now I REALLY need help. Is there any way to get that oil out of my engine now???

holmesnmanny

It'll burn off don't worry about it.

grjr

If it was a lot of oil you can pull the ECU fuse out and just crank the engine over a few times leaving the spark plug(s) out, the oil will either spray out the spark plug hole or go out the exhaust.

ctbrown1

ccauthe

Thanks everyone. The engine burnt the oil off with no problems. Unfortunately when I did my compression test the pressure on the 4th cylinder was only 62psi (the others were 160) so I'm guessing I have a blown head gasket

supertace91

maybe your radiator has corroded inside

holmesnmanny

it's normally the 4th cylinder that goes when the head gasket goes so it sounds like it's the case...just for ***** and giggles you can do a leakdown test to confirm it is a leaking head gasket

KidDxbOrI

Sounds to me like it's the head gasket , although Hondas do have an issue that if the ground wires on the thermostat neck are loose , dirty , ripped will make the temp gauge think the car is over heating it happened to me . So check that lmk if it helps

ccauthe

Thanks again everyone. I will check the ground wires on the thermostat, and I think I'm going to attempt to replace the head gasket. If this thread lasts that long, I'll give you all an update if that works.

ccauthe

Okay, so it looks like I am going to have to try to replace the head gasket. Having never done this, I've got a few questions before I get started--

1.) Are there any unusual tools I will need (other than socket wrench, plyers, torque wrench...)?
2.) As far as I know, I only drove the car about 40 miles (14 trips of 3 miles each) after the head gasket blew. Is it likely that I will need to replace anything else, or should I just be able to replace the gasket?
3.) Any other tips (do's or don'ts that aren't intuitive for someone who has no experience doing this repair)?

thanks again.