[Elcoman]

My 99 Honda Civic keeps overheating. I changed the radiator because there was a big crack in it. That was not the problem.

I pulled a heater hose while filling the radiator to help get out trapped air.

I ran it till the t-stat opened, then fill it. I have also checked the t-stat with boiling water and a temp probe.

The car will top out the temp gauge at a light or idling then drop right down to normal temp. the fan is coming on.

The car is also using water.

I am assuming head gasket, but no coolant is coming out the exhaust.
The oil is fine, no water there.

[csmnlm]

Pull the spark plugs out of the engine. See if there wet or have a green tint to them.

[Philip]

Have you checked that the cap will hold the proper pressure?

[harleighguy]

I am a Tech for a local Honda dealership. Most of the time we never see any coolant at the tailpipe when there is an overheat condition, however the upper and lower radiator hoses will pressure up pretty fast and be rock hard, we use a gas analyzer and sniff at the top of the radiator neck to check for CO in the coolant. I'd pull the head and get the head pressure checked and inspected for warpage. If it's good then use a HONDA headgasket and also REPLACE the T-stat with a HONDA one. HOW many miles are on the motor and
T-Belt? It might be a good time to replace the waterpump too~ Blown headgaskets in Civic's are common, especially if the T stat has never been replaced and normal maintenance is NOT performed. What is the condition of the radiator?

After re-reading the post I see that you say the car is using water, look at the weep hole on the water pump to make sure there isn't a green crud buildup, if there is it's water pump time too!

[Elcoman]

Originally Posted by Philip

Have you checked that the cap will hold the proper pressure?

The rubber looked good on the old rad cap, I replaced it today as last resort.
It didn't cure the problem.

[Elcoman]

Originally Posted by harleighguy

I am a Tech for a local Honda dealership. Most of the time we never see any coolant at the tailpipe when there is an overheat condition, however the upper and lower radiator hoses will pressure up pretty fast and be rock hard, we use a gas analyzer and sniff at the top of the radiator neck to check for CO in the coolant. I'd pull the head and get the head pressure checked and inspected for warpage. If it's good then use a HONDA headgasket and also REPLACE the T-stat with a HONDA one. HOW many miles are on the motor and
T-Belt? It might be a good time to replace the waterpump too~ Blown headgaskets in Civic's are common, especially if the T stat has never been replaced and normal maintenance is NOT performed. What is the condition of the radiator?

After re-reading the post I see that you say the car is using water, look at the weep hole on the water pump to make sure there isn't a green crud buildup, if there is it's water pump time too!

The car looks in great shape, I would assume it was well taken care of by the people we got it from.
The Rad is new, the cap is new, t-stat works I checked it.
The hoses don't build pressure right away.
I don't have a gas analyzer.

[Elcoman]

Originally Posted by csmnlm

Pull the spark plugs out of the engine. See if there wet or have a green tint to them.

I'll check that tomorrow.

Thanks guys for the replies.

[Chuck]

Are you getting a good flow? I just did this for my Office Manager last week. Same symptoms and it turned out the be a water pump. We replace it and put in a new timing belt and that did the trick. She had some flow but not enough to cool the Civic down. Just another thought.

Chuck

[Elcoman]

The upper hose is off to the side of the neck of the rad, but the water does gush out pretty fast with the cap off.

It also cools right down when the fan kicks on, maybe the fan should kick on sooner?

[harleighguy]

I know you say the T-stat is working, but is it a HONDA one? WHY was the radiator replaced? If the T-stat failed and the radiator cracked then I'd say the headgasket is also blown~ But hey i'm just a Honda tech.... Almost all the Civic's we do blown head gaskets on have a bad radiator/T-stat problem and almost never have wet plugs. AFTERMARKET parts don't have the same quality/performance that factory HONDA parts do! We get a fair amount of complaints that "my car runs bad" and it's because of aftermarket parts being installed trying to beat the factory pricing. I hate to say this but cheaper parts = cheaper performance. We have a sign at work that reads; Almost factory parts ALMOST work...

[Elcoman]

Yeah, I am going with blown head gasket.

[Chris R]

Is the heater blowing warm or cold when the guage goes up?

[Elcoman]

I am not sure about the heater.
The car is actually my girlfriends daughters car, Grandpa is taking it to a shop.
He knows the owner, so I will know for sure on Saturday.
I have enough cars in my fleet already.

[Elcoman]

I think the guy is ripping him off, he says everything is melted and now needs a new motor.
I want to go and check it out myself, but I don't want to piss off the soon to be in-laws.
There was no coolant in the oil, no oil in the coolant. The car still ran great had lotsa of power for a Honda, how could it need a new motor?

When it did overheat it went right back down to normal within seconds.
you could hear the fan and watch the needle go right back down.

[Chuck]

It's just like the transmission chain stores. Many offer a free computer error code diagnosis to get you in to the shop. Let's see, the error code says you need a new exhaust sensor, but wait... you also need a complete tranny rebuild. I'd look for a second opinion. If it runs well, doesn't smoke and has no fluid problems, just drive it. They are bullet proof.

Chuck