Engine hot, it runs rough

[hondadad]

My daughter has a 1994 Honda Civic. It has 130,000 miles on it, I bought it with 120,000. It runs fine when you first start it up, and to where ever you're going. But after it gets hot, and you turn off the engine, when you start it back up it runs rough and shakes a little like the timeing is off.

I'm thinking timeing belt and tune up, but that's just a shot in the dark. Any ideas?

[xAUTOxRACERx]

I think you can give the timing belt and tune-up a shot. But also flush out the coolant and check the cooling system!

[hondadad]

Last year I put in a new radiator, since the old one was leaking. Even when it's running rough, the temperature guage is less than 1/2 way.

Originally Posted by hondadad

My daughter has a 1994 Honda Civic. It has 130,000 miles on it, I bought it with 120,000. It runs fine when you first start it up, and to where ever you're going. But after it gets hot, and you turn off the engine, when you start it back up it runs rough and shakes a little like the timeing is off.

I'm thinking timeing belt and tune up, but that's just a shot in the dark. Any ideas?

[integrasedan]

when you put in radiator, you should have also replaced the thermostat.

also check if fans are kicking in.

[hondadad]

I'm pretty sure I replaced the thermostat, also the hoses and radiator cap, which must have a gold seal on it because the cap was $13. The fans are kicking in, both the radiator and the other one. Last year was pretty much a fix the cooling system summer.

If anyone has had a similar problem, I'd really like to hear from them.

[madmaxEKhatchB18C5]

my friend just had this exact same issue with his 97 civic EX

what we did was the following little tune and it worked WONDERS...i tried to give this advice to some hondamommy a week or two back, but she wanted to spend $$$ on a timing belt change, so do what you like:

1. inspect timing belt...only change it if it is worn.
2. replace all spark plugs (we replaced with platinum 4 points, NGK is great too)...i think you have issues with getting fire to each cylinder=rough idle (not always getting gas/air mixture lit)
3. check and possibly replace the rotor blade...my friend's was caked in debris...means your'e not gonna get fire all the time=rough idle (not always getting gas/air mixture lit)
4. replace PCV valve...i honestly think every old car should have this done...it will clean up a rough idle if your old PCV valve has not been replaced in a while...keep you running cleaner and more efficiently=cooler.
5. air filter
6. oil filter
7. oil change, but add back the Lucas Heavy Duty Oil Stabilizer at 20%, 5W-30 synthetic for the other 80%--this stuff works wonders.
8. adjust the throttle cable...9 times out of 10 there will be some slack in it, giving you sluggishness
9. don't just flush the radiator--BACKFLUSH the ENTIRE cooling system...Prestone makes a great adapter that taps into one of the cooling lines coming off of your block...add that and you can hook a garden hose up to your cooling system and flush the ENTIRE system out...the first time i did this i was shocked as to how much junk was trapped in there.
10. we also did an engine oil cleaning treatment...they say it is not recommended for really old motors b/c there will be cracks in the block and this stuff will clean out the gunk sealing those cracks...i've only done this on cars with around 70,000-90,000 miles, but man it makes a HUGE difference...i think it is possible to do it on older cars, but you MUST use the Lucas oil stabilizer to fill in those cracks after the cleaning.

after doing all of this to my friend's civic, she is running MUCH cooler (it was scary how how his car was getting b4 these cahnges) and he's already noticed improvements in power and fuel economy...good luck and let us know what you do.

[hondadad]

I called my old mechanic, who sometimes gets it right and other times doesn't. He thought it sounded like a broken head gasket. Does this seem reasonable to anyone?

[GScivic7]

there would be coolant in the cylinders and he should have white smoke coming out of the exhaust if it is a blown headgasket. Sageuvagony knows this first hand lol

[hondadad]

Ok, probably not a broken headgasket. I'll take it to the dealer tomorrow, pay the money to hook it up to the computer, and hope it's not too expensive. My daughter thinks I should sell it and buy her a new one, yeah right.

[CivicEXRider]

It could very well be the headgasket. I've had several blown ones over the years couple in my MarkIII Supra (7MGTE motors are great if you want to learn about blown headgaskets and 2 in my Honda Civic. What you have is probably a small tear in one of the metal layers of the headgasket. Normal idle will not lift the head enough to produce blow by into the water jacket. But when accelerating the head will lift just enough to pressurize the cooling system with hot air. If this happens, you'll see the overflow tank filling up possibly running out. When the motor cools back down the water will return back into the radiator and most of the air in the system will be blown out the overfill tank.

Go to the parts store and pick up a combustion leak block tester or compression tester. I'd probably go with the combustion leak block tester. This actually shows you if you get exhaust gases mixed in with the coolant.

[hondadad]

Well, it looks like it was the headgasket after. Since a couple of you thought it might be the problem I decided to take it to my old mechanic, rather than the dealer. He'll be a whole lot cheaper. Thanks for everybody who pitched in, if it hadn't been for you guys I would have taken it to the dealer and really been cleaned out. Now I'll probably have enough left over to get a tune-up.

[GScivic7]

I'm glad there was someone here to correct me

[E Honda]

Make sure the radiator is not clogged,,,,,,Not only inside but check to make sure air will flow through it..I have had radiators get filled with grass and crap restricting the air flow. Also I have not seen the water pump mentioned as I have seen the impeller on the water pump go crazy and not leak a drop from the weep hole.......does your water level drop.

E.Honda

[sageuvagony]

3fufwdgtdjkghjkgcshgvnjcghjfsdghfdjkjfd lghfdg hjg hjgh fgf 0yt896t9753iu ewnt790 n9yn&(* ^%#*&HNYR(WUDNS TR*)HN &I#@(*&NY#&$ GU#WUOJN$^T($RIUNGBFKLJNWTRIWMG FKJ>EJNRTTR LSWUGFNRT&LSWMHR KSKG FHSKT*R FFY@N&%@NHWUTYTEHWE T*&86o3bt483oh6327h575986487568^$*%^@^%*&g86bytggt dbhrhew468rew56t86g447GGB*&