YACT: 1993 Honda Civic overheating while idling!

[Nocturnal]

I have a 1993 Honda Civic Si bone stock. The only modifications are done to the suspension.

My car is now overheating. Overheating as in the temp gauge will go all the way to the top of the line if I am idling. If I drive it?s ok, and it goes down to where it normally is.

Someone mentioned it may be my thermostat. I honestly don?t know how to change that out nor do I know where to get a new one from.

Also I just checked my engine out and it looks like there is water leaking from a hose connected to the bottom of the intake manifold near the injectors.

Any advice?

 

[RagingBITCH]

Have you checked your coolant to make sure it's at the proper level? When's the last time you changed it out/flushed out the radiator?

 

[Nocturnal]

I haven't changed or flushed the radiator for quite some time. Maybe that is something I should definately do.

 

[Iron Woode]

Originally posted by: Nocturnal
I have a 1993 Honda Civic Si bone stock. The only modifications are done to the suspension.

My car is now overheating. Overheating as in the temp gauge will go all the way to the top of the line if I am idling. If I drive it?s ok, and it goes down to where it normally is.

Someone mentioned it may be my thermostat. I honestly don?t know how to change that out nor do I know where to get a new one from.

Also I just checked my engine out and it looks like there is water leaking from a hose connected to the bottom of the intake manifold near the injectors.

Any advice?

Mechanic?

 

[Zenmervolt]

Turn on the A/C. Does the temp go down? If yes, then the temp sensor in your thermostat is not triggering the radiator fans as it is supposed to do. If no, then one of the fans is broken. Turning on the A/C forces both fans on, so if it's the temp sensor then the A/C witll turn the fans on and bring the temps down.

This same thing happened to my 1988 Accord and that's what it was.

ZV

 

[hevnsnt]

(first off I know nothing of your car)

But do you have an electric fan behind your radiator? Check the relays & motor of this fan to make sure it kicks on.. My jeep just had the same problem the other day, turned out to be a bad relay.

 

[Nocturnal]

Originally posted by: Zenmervolt
Turn on the A/C. Does the temp go down? If yes, then the temp sensor in your thermostat is not triggering the radiator fans as it is supposed to do. If no, then one of the fans is broken. Turning on the A/C forces both fans on, so if it's the temp sensor then the A/C witll turn the fans on and bring the temps down.

This same thing happened to my 1988 Accord and that's what it was.

ZV

Even with the a/c on it doesn't go down until I drive or hit the gas. Once I hit the gas and rev the car a little the temp gauge itself goes down.

 

[ThisIsMatt]

Have you even checked the coolent level? Check it when the engine is cold.

 

[OS]

the thermostat might be bad. My old accord did this, it said it was overheating when in fact it wasn't.

 

[Crucial]

Sounds like a faulty fan to me.

 

[Thegonagle]

First, the leak must be addressed, and the coolant refilled.

Then test the cooling fan by allowing the car to idle with the AC off, and waiting for the cooling fan to turn on. This should happen by the time the gauge rises slightly above the middle.

If the cooling fan doesn't turn on, that explains the overheating at idle.

 

[Eli]

NEVER let your engine get near the H if you can at all help it.

Hmm... When you rev the engine, the temp goes down?

That's strange. Water pump on the fritz, perhaps?

 

[ThisIsMatt]

Originally posted by: Eli
NEVER let your engine get near the H if you can at all help it.

Hmm... When you rev the engine, the temp goes down?

That's strange. Water pump on the fritz, perhaps?

No, when he drives, which makes sense.

 

[95SS]

Originally posted by: ThisIsMatt

Originally posted by: Eli
NEVER let your engine get near the H if you can at all help it.

Hmm... When you rev the engine, the temp goes down?

That's strange. Water pump on the fritz, perhaps?

No, when he drives, which makes sense.

Once I hit the gas and rev the car a little the temp gauge itself goes down.

I agree with checking the water pump. Could be the coolant isn't being circulated efficiently at low RPM's.

 

[xenocyd3]

water cooling

 

[TechnoKid]

Originally posted by: 95SS

Originally posted by: ThisIsMatt

Originally posted by: Eli
NEVER let your engine get near the H if you can at all help it.

Hmm... When you rev the engine, the temp goes down?

That's strange. Water pump on the fritz, perhaps?

No, when he drives, which makes sense.

Once I hit the gas and rev the car a little the temp gauge itself goes down.

I agree with checking the water pump. Could be the coolant isn't being circulated efficiently at low RPM's.

if your milage is up there, around 90k, then thats about time for a timing belt and water pump replacement if you haven't already done so. If you are over this milage and have not yet done a timing belt and water pump, I would suspect this first over a faulty fan relay or temp sensor.

The leak definately must be addressed and fixed first, and then the coolant level can stabilize; i bet you are low on coolant or leaking it pretty bad which could cause air pockets in the coolant system would could cause you to intermitenly overheat. That hose under the throttle body is either the little tiny hose to heat the throttle plate, or the bigger hose that comes out of the rear of the block then through the thermostat that goes to the bottom hose of the radiator.

 

[HiTek21]

sounds like you've got air in your coolant system. Get that leak fixed and bleed the coolant system till you get all the air out. It may be the clamp on the hose thats loose or the hose may have a leak. I would inspect all your hoses and make sure nothing else is leaking.

I had the hardest time isolating my coolant leak on my legend. I had the same problem you described. It would over heat once in awhile while idling (even sometimes while driving). I replaced the thermostat and that didn't do anything. I monitored the fans and made sure that they came on at the right temperature (and they did) but it would still over heat a bit. I would turn on the heater while idling and no heat would come out (as soon as I started driving the heat would start coming out) I asked on the legend board and they told me i had air in the coolant system. So I bled the air out it solved my problem. The problem came back turns out I had a leak somewhere.

When I had my water pump / timing belt changed the guy at the shop said the previous guy who worked on it put silicon on the water pump instead of the gasket and it was leaking so they got that all fixed up. Then my upper radiator hose was swelling up letting coolant seep out of the end, so I replaced the upper and lower radiator hose. Still I was losing coolant somewhere, turns out there was a pin hole sized leak in my radiator, it would evaporate as it came out because it was such a small leak but it finally burst and fluid started gushing out. I replaced the radiator and now finally I have no problem with losing coolant.

I would not let that temperature gauge hit the top (for very long) or you may blow the headgasket and that will cost an arm and a leg to fix.

 

[Calin]

The thermostat is a tempertaure controlled valve that opens to let the cooling liquid go into the radiator. If the coolant is not warm, its circuit is only inside the engine and interior heating system. When the coolant warms (at about 75 Celsius) the thermostat starts to open, and must be fully opened at some 105 Celsius.
If the spring of the thermostat is too stiff, the thermostat won't open if there is not enough pressure. So you should check either the thermostat or the water pump. The water pump moves more water at higher pressure when the engine is is higher rpm, so this might be why while driving the temperature goes to normal.
The fan (fans) on the radiator (if electric and not belt-activated) are probably controlled by a thermocouple in the radiator's water circuit, not in the engine water circuit. So, the fans probably won't start if the water is not flowing thru the radiator, no matter what the engine temperature is.

Calin

 

[Quixfire]

Nocturnal, I see you have been given some very good advise. Please let us know what you have done to resolve the concern.