Hello!

I am a newbie to these boards and have searched the forums for an issue I just encountered yesterday while failing a SMOG test and can't pinpoint the issue.

I have a 92 Honda Civic LX and it failed SMOG. After the Cat was replaced, I can pass however the SMOG mech mentioned that the car would overhead at stop and go type of hot traffic. at the 15 mph smog test apparently it was boarder of failing.

He recommended running the heater to keep the motor cool when it starts to overheat.

he also said he thinks its a leaking headgasket. After reading some posts here (thanks for the education), I doubt this since there are many steps to take before coming to that conclusion.

My question is....How do I know if it a radiator, radiator cap, coolant therm unit or a headgasket?

I was going to take it for a drive today and do stop and go traffic to see how it flucuates the heat monitor. Apparently it won't overhead while driving on highway driving?

Thank you guys so much. I really need some direction on this.

 

check your radiator fan boodrow!!

 

Should I take it to a Radiator Shop or can I test the fan myself? If so, how?

 

to test the fan the easiest way is let the car run with ur heat off. once the car gets up to temp the fan should kick on. if ur there all day waiting for the fan to come on then obviousley its no good. also u can check ur radiator cap by simply taking it off (when car is cold) and inspect the rubber gasket attached to it. if it looks rough then try replacing it. does it leak. u could also get it pressure tested to see if its leaking. if it were the head gasket u would be blowing some white smoke out the muffler and loosing compression.. (lack of power) depending how bad. the reason it is less likley to overheat on the highway is all the fast moving air cooling it down versus sitting in one spot.. no air flow if ur not moving.

 

ok great!

There are no leaks that i've noticed.

the smog guy said if i turn the heater on in the car (flow it inside) that would keep the car from overheating.

does that sound consistent with a radiator cap, radiator or temp sensor?

i'm off to check the cap now

 

well turning the heat on will keep it cooler but it wont definitely stop it from overheating. when you turn on the heat the coolant goes through your heater core which is like a small radiator so it helps a little. also replace your thermostat, its only like a $6 part. and about the fan, turn the car on, pop the hood and wait about 5-10 minutes and see if it turns on. if not then go turn the ac on all the way with the car still running to see if it turns on. it should turn on with the ac on all the way. if it doesnt then test the plug going to the fan with a multimeter and see if it gets a 12V signal if it does and the fan dosent work even with the ac on then replace the fan, but if it dosent have a signal then follow the wire and look for a short.
good luck.

 

ok i checked the radiator cap looks pretty good. no cracks or anything like that.

I want to change out the termostat just to be safe.

Where is it and is there a how to? I imagine its easy (I hope) and I will change it today if I can get directions on where its at and how to change it.

thank you

 

well someone else is going to have to help you with the location on this one, as i dont own a honda, but i have some general knowledge that applies to any car. but i can give you a synopsis on how to do it.
you are going to remove some sort of housing which the upper radiator hose will be attached to (this will make a mess and antifreeze is dangerous to animals), and inside will be the thermostat. take the old one out, put the new one in with the little hole on the top side. then you are going to take your radiator cap off and burp the system. to burp the system you start the car and let it run with the cap off and add a 50/50 mix of antifreeze and water as air bubbles come up. this should take about 10 minutes or so. when you think its done put the cap on and take it around the block, and then burp it again. do this process(burping) until you are confident there are no air bubbles in the system.

 

Before you replace the thermostat check the fins on the radiator. About 10 years ago my 92Si began to run hot. I noticed the fins were no long attached to the tubes on the radiator.

The Thermostat is under the Throttle body behind the head.

 

here, this should help you.
anything else just lmk.