Weird overheating problem

[Nic Sanchez]

The Car

1994 Integra GS-R
Miles 185,000 plus

The car get very warm/overheats early Monday mornings, 4:00 AM, about 98% of the time. The car usually sits on weekends.
The gauge gets past halfway when I will shut it down. Normal temperature is below halfway. The car does not get hot when the outside temperature is warm/hot.

The top radiator hose is hot but the bottom radiator hose is slightly warm. I've replaced the radiator due to a leak, the thermostat has been replaced twice, the water pump once and the radiator cap. I've had the fan switch and wires checked.

Also when this occurs the heater will not blow hot air, even when I switch the A/C on.

I've not found any leaks or puddling under the car.

I do have a slight oil leak around the head gasket, I'm putting about a quart of oil and refilling the reservoir about every two weeks.

The mechanics I use are stumped. They've suggest that I have the head gasket replaced but are not sure if this will solve the problem.


Any comments or questions are welcomed.

Thanks,
Nic

[Max Hayter]

Your post would suggest that this only happens on Mondays at 4am, and for the rest of the week functions perfectly.

This is indeed a strange problem

[George Schilling]

The Car

1994 Integra GS-R
Miles 185,000 plus

The car get very warm/overheats early Monday mornings, 4:00 AM, about 98% of the time. The car usually sits on weekends.
The gauge gets past halfway when I will shut it down. Normal temperature is below halfway. The car does not get hot when the outside temperature is warm/hot.

The top radiator hose is hot but the bottom radiator hose is slightly warm. I've replaced the radiator due to a leak, the thermostat has been replaced twice, the water pump once and the radiator cap. I've had the fan switch and wires checked.

Also when this occurs the heater will not blow hot air, even when I switch the A/C on.

I've not found any leaks or puddling under the car.

I do have a slight oil leak around the head gasket, I'm putting about a quart of oil and refilling the reservoir about every two weeks.

The mechanics I use are stumped. They've suggest that I have the head gasket replaced but are not sure if this will solve the problem.


Any comments or questions are welcomed.

Thanks,
Nic

Nic, I think you should enlist the services of a Priest specializing in Exorcism.

If you find good one, I need one for one of my trucks that has an equally mysterious problem.

This only happens on Monday morning @ 4:00 AM. I know if I were your car, I'd be less that happy having to start up and haul my owner around at that hour after a big weekend. Try starting it at 10 or 11 and see if that makes a difference.

Just to get this straight, this only happens after the car sits for a few days? And after the Monday morning incident, it returns to normal for the rest of the week? So what could happen during those days of rest? If you do have a leaking head gasket, could it be introducing air into the cooling system which then hits pump and the pump stops circulating coolant? Just a thought.

[Doug Kott]

Nic should have said that any constructive comments are welcomed.

(George, that one was aimed at Max, of course! )

[Eric Clements]

Strange that it only does it after sitting but it sounds like you are getting air in the system.

[Nic Sanchez]

Your post would suggest that this only happens on Mondays at 4am, and for the rest of the week functions perfectly.

This is indeed a strange problem

I wouldn't say only on Mondays. About 95% on Mondays.

It happened once on a Friday morning.

Once I pull over and let it sit for about 5 minutes it works fine for the rest of the week.

Could a bad head gasket allow enough air for this to happen?


Thanks,
Nic

[George Schilling]

Your post would suggest that this only happens on Mondays at 4am, and for the rest of the week functions perfectly.

This is indeed a strange problem

I wouldn't say only on Mondays. About 95% on Mondays.

It happened once on a Friday morning.

Once I pull over and let it sit for about 5 minutes it works fine for the rest of the week.

Could a bad head gasket allow enough air for this to happen?


Thanks,
Nic

It sounds to me like there is enough of a connection that replacing the head gasket will probably solve your problem. If you intend to keep the car, fix the obvious first. Then don't be surprised if you no longer need an exorcism. ;)

[Jayson Woodruff]

No hot air means no water flow. So at least you can start there. Were all your parts replacements recent, any of them co-inside with the start of the problem? It wouldn't surprise me too much if at 200K you were on your second water pump, or if someone put a thermostat in backwards.

My gut feel is like Erics. Air in the system, where maybe the pump is cavitating. I assume the coolent isn't low. Have you burped it throughly?

Jay W

Also when this occurs the heater will not blow hot air, even when I switch the A/C on.

[Daniel Y.]

In my experience, if the cooling system is service correctly (new water pump, thermostat, clean/new radiator, fans in good order) and you're still overheating, it's most likely a blown HG. At 185k, you might want to look into a full rebuild, or a used, low mileage motor.

One last thing you might want to try is to bleed the cooling system from the nipple on the thermostat housing as this often get overlooked.