jared99

Working on a 93 civic DX. Actually buying it and fixing it up. However, it keeps overheating. There's plenty of coolant. The radiator hose that goes into the engine never seems to get hot, as if the thermostat is stuck closed, so I replaced the thermostat, and the hose is not plugged up. Same issue. I drove the car on the highway on a cool night and it was fine. However, driving around town makes it go all the way into the red. Even idling it in the driveway will make it overheat into the red. Cooling fans work fine, they turn on when the engine reaches the proper temp and the blades are not bent (one of course only turns on if the A/C is on, car overheats regardless). If you pour water through the top of the radiator, it comes out the bottom hose (I disconnected it just as a test) with no problem. The girl I'm buying it from says it had a cooling system flush a couple months ago and it didn't fix the issue. If you take the radiator cap off, it hisses so the system is pressurizing. The water pump is driven by the timing belt so if it had locked up most likely there would be water leaking and it would be shredding teeth off the belt. Overheats whether or not you have the heat turned on full blast to cool it.

Any ideas what to try next?

symph0ny

I have the same problem with my 94 dx. The fans stopped working right after I got it, but it does overheat at an idle (which I'm told is not supposed to happen.) One of the hoses just blew up, and sent coolant everywhere, so I'll be changing all the hoses I can get at.

I know this doesn't sound very helpful, but I do have a suggestion. My setup kept on frying spark plugs, I couldn't deal with it, so I finally bought 3 steps cold denso plugs. The spark plugs haven't gone out on me yet, so I'm glad for that.

If I find a problem when I change the hoses (soon hopefully), I'll let you know.

Lord Helmet

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jared99 &raquo;</TD></TR><TR><TD CLASS="quote">Working on a 93 civic DX. Actually buying it and fixing it up. However, it keeps overheating. There's plenty of coolant. The radiator hose that goes into the engine never seems to get hot, as if the thermostat is stuck closed, so I replaced the thermostat, and the hose is not plugged up. Same issue. I drove the car on the highway on a cool night and it was fine. However, driving around town makes it go all the way into the red. Even idling it in the driveway will make it overheat into the red. Cooling fans work fine, they turn on when the engine reaches the proper temp and the blades are not bent (one of course only turns on if the A/C is on, car overheats regardless). If you pour water through the top of the radiator, it comes out the bottom hose (I disconnected it just as a test) with no problem. The girl I'm buying it from says it had a cooling system flush a couple months ago and it didn't fix the issue. If you take the radiator cap off, it hisses so the system is pressurizing. The water pump is driven by the timing belt so if it had locked up most likely there would be water leaking and it would be shredding teeth off the belt. Overheats whether or not you have the heat turned on full blast to cool it.

Any ideas what to try next?</TD></TR></TABLE>


I'm betting it was only a "flush and refill" job and not a true "power flush" like most competent shops will do or you can do yourself. If you power flush the cooling system instead of just flush and refill, it will help unblock any hidden mineral deposits stuck in the cooling system passages. I also bet she just used regular tap water instead of the recommended distill water which has no minerals in it.

Worst case scenario is that you're in a early stage of a blown head gasket. Do a compression test to see if the head gasket is in good condition.

All the symptoms you mention above is exactly what happen to my ol' 91 B18A engine prior to to blowing the head gasket.

phanatic

When my hatch was overheating there was a tiny crack in my radiator. Check to see if any fluid is on your front grill.

killerformula

just because the system is pressurized doesn't mean its holding enough pressure. Make sure its holding the 15 or 16 PSI like it supposed to. The old cap may only be holding 10

fmrprojects

sounds like you could have a faulty therostat. get 1 from the dealer. i got 1 before from a auto parts store and it was not working . and is your car blowing out white smoke. white smoke could be a blown head gasket

jared99

It's not leaking any fluid, and not blowing any smoke. I'll replace the cap since it's cheap. I personally don't think the new thermostat is bad too, but just to check it I'll take the thermostat out and just let the water cycle through continuously and see if it still overheats. Definitely could stand to have a compression check as well. Does Autozone or Pepboys rent the tester out? I know it's only $20 for a cheap one but I can't spend that right now just to test this one car since I'm out of a job. Guess I'll call them tomorrow morning.

Thanks to everyone for the help so far..I'll go get after it tomorrow morning and see if I can figure out some more.

E.Honda

How do you know the water pump is not bad?
Is it boiling?
Gauge could be wrong. Sending unit could be bad.
Radiator could be stopped up inside OR outside.

E.Honda

allmotor89hf

try replacing the radiator cap?
maybe air in the system, try draining and refilling?

pro1342

are you sure there isn't a problem with the temp sensor for the gauge that is located in the side of the cylinder head under the distributor?

jared99

I don't think it's the temp gauge because if that was bad, it would probably immediately show as hot as soon as the car is started, rather than waiting until the car is warmed up. Also, the car doesn't seem to overheat as bad when I'm moving on the highway, which would make sense, so I think the gauge works.

I don't know that the water pump isn't bad, but when they go bad, usually either it seizes and since is driven by the timing belt, it will strip the teeth on the belt or if it could actually start it would have a super choppy idle because the belt wouldn't be able to turn easily. Doesn't seem to be an issue right now. Other times when they lock up they crack, (there's actually a relief valve on the pump itself isn't there?) and it's not cracked or leaking. Also the system is pressurizing (at least somewhat) so it would seem as if the pump is working.

I'll be honest, I don't know what you mean by the radiator being stopped up outside? The radiator isn't stopped up inside because I can pour water through the top and it comes out where the lower radiator hose attaches (I removed the hose to test). I guess by outside you mean in the rest of the cooling system, which could definitely be a possibility.

Also, the coolant seems to be super hot whenever I stop the car after it overheats although it doens't seem to be flowing through the system properly. I'm not sure if it's boiling, but it probably is because there's a decent amount of steam that comes out into the overflow tank, so I think the gauge is right and the car is actually overheating.

Just draining and refilling will remove the air from the system...?

Thanks again

E.Honda

Stopped up on the outside.
Means dirt or debris is preventing air from passing through the fins of the radiator. I had this happen on my corvette once.

KingKhong

same thing happened on my brother in laws 94 lx, he couldnt find the problem so he traded it in

jared99

UPDATE....

Alright, here's what I found out today. I removed the thermostat so that it would just cycle coolant constantly. Seemed like it was working, the engine of course took a lot longer to warm up. I was gonna drive it around the block and when I walked by the back of it I felt something wet hit my leg. Sure enough, there was water and steam coming out of the exhaust, and it had the sweet coolant-burning smell to it. Not sure why I never saw that before, maybe had to do with the thermostat regulating it most of the time. I ran a compression test on it, and by accident I didn't connect the gauge to the hose correctly when I ran it on the 3rd cylinder, and coolant was spraying out the end of the hose! It's probably the exhaust getting in the coolant that is making it a gray-ish color. The head gasket is gonna need to be replaced, but I wouldn't be surprised if the actual head is warped also. Also on cylinder 4 when I removed the spark plug it was COMPLETELY covered in oil, so bad it was actually dripping off the plug and my socket.

I don't think I'm gonna buy the car from her unless I can get a super cheap deal on it, and they don't want to go less than $500. It's a 93 DX, auto with basically zero options. It does have A/C, I charged the system last week and it seems to be cooling, but I think has a slow leak. Has the base engine and a ton of dings and scratches in the paint. It only has 117k miles on it but it looks like it has closer to 200k. My Integra has 113k miles and is in much better condition. When I changed the oil, it was red! When it idles, it sometimes idles like it has a vacuum leak. Also it was owned by some friends of ours up north so the underbody is all rusted out, and the front has a small hole where a truck with a trailer hitch backed into them. The car has needs a ton of work that I can do myself but probably won't ever make the money back on it.

Probably gonna have to pass on this one.
Thanks for everyone's help!

jared99

...Probably is idling rough because of coolant seeping into the cylinders...

beelzebub

Did you bleed the cooling system? Air bubbles get trapped in there and will cause coolant to boil. On the older EFs with A6, there is a bleeder valve by the waterneck that you use to do that.

jared99

btw, just to let everyone know, i replaced the head gasket this weekend and it fixed all the issues. thanks for everyone's help.

EG6LS

the "white smoke" you're refering to is not smoke. It's steam. When you blow your head gasket, the water gets into the cylinder and flashes off as steam.

jared99

thanks... i was using the terms interchangeably since i just assumed everyone posting understood that it's really steam.

bubblehead

sucks man sorry

siregcivic

my car used to overheat alot.... i did.. headgasket.. waterpump.. thermostat... new hoses.. new thermostat.. radiator cap.. new thermostat... no thermostat.. replaced the single core cx radiator with a dual core and it barely even gets up to 140 now..

my radiator seemed like it flowed good. but it was ****.. could be your problem too.. replace it with a dual core from autozone or something.. i got lifetime warranty on it so its nice if it fox up

siregcivic

oh.. my x's car when she bought it it was fine.. a week later overheated all the time.. so i replaced everything on the outside.. just like my post above.. went to do the headgasket.. and the actual cylinder wall was cracked i mean chipped off on the top on the side where the water is so it wouldnt seal.. the oil on the sparkplug and your socket could just be a bad gasket for the sparkplug tube in the valvecover