Help with overheating and no heat inside

I have a 92 Integra, i bought the car with a B16 Vtec swap done to it.
I have replaced the thermostat and the car is still overheating. I also have not heat on the inside, it is blowing cold air. I do know that the fan does not kick on at all. But i am lost on what could be causing the problems. Also the AC has been completely removed. Can somebody please give me some advice and help.

Thank you for any help

any leaks?coolant in the system?passgener side floor boerd wet?oil look milky?any smoke ?

no leaks, i have coolant in the system, oil is not milky, and no smoke

Behind and under your glove box there should be essentially a heater duct where the a/c evaporator used to be, or atleast if the core is removed the housing should be closed up.

If you don’t have a duct here, you have no heat.

As for overheating, does it happen when the car is in motion, or just when at a stop?

Have you connected power straight to the fan from the battery to see if the motor still works?

in motion, actually if i am sitting with the car on it drops a little
as far as connecting the fan to the battery how do i do that?

Your car should not be overheating while you are driving it. While scooting along at 15mph or more there is more than enough airflow to keep your motor running happily, unless you have another very serious problem. If the fan in fact does not work, I would put that on the back burner for now…

My radiator fan still does not work, and when I let my car sit for too long even in fairly cool weather it will start to slowly overheat simply due to the lack of airflow. However if I am in motion it stays nice and cool…

The only thing that I can think of is a clogged cat, or that your car is running extremely lean.

Remove the shield over your header, if either of these are your problem your header will get insanely hot and possibly glow red at higher rpm’s.

could a bad water pump be the cause of both of my problems?

I would like to say possibly, but it doesn’t explain why you are overheating while driving and cooling down at idle. It wouldn’t hurt to check it, though.

Possibility: Head gasket is allowing exhaust to leak into your coolant. With your car running does your overflow tank bubble occasionally or at all?

is there anyway to check it without taking it out?

Not that I know of. I would check your head gasket first though, now that I think about it that makes perfect sense why you would overheat while driving. Higher rpm = more exhaust entering coolant = more heat.

Honestly, head gaskets are a much more common problem, and it would be more likely to be your thermostat than your water pump if it was anything else. Ask anyone.

ninja edit: I’m not sure what you mean by take it out, the water pump or the overflow or your head?

just put a new thermostat in

I understand that, I’m just using it as an example of the chances of your water pump being the culprit. Remove your head and check your gasket. I’d put my money there.

ok thanks what exactly am i looking for?

A void in the gasket where your exhaust is allowed to slip into your coolant lines. The reason you wouldn’t notice coolant burning is because of the higher pressure of the exhaust gasses hence why they are forced into the coolant rather than the other way around as is with coolant leaking into the oil.

It may be hard to spot, it doesn’t have to be very big. If your G2 is not your daily driver I would order a new oem b16 gasket and wait for it to arrive, then slap the brand new one on. Try not to go with anything other than oem if you can help it, honda really does make the best gaskets for their motors.

ok thanks for all your help, sorry i am not real smart when it comes to engines

The only stupid questions are the ones that go unasked :slight_smile: Keep us updated.


The headgasket would be the last thing to check

you have had a couple good suggestions about the cab heat and you didnt awnser.

so let me repeat it, is there a piece of ductwork where the A/C line come thru the fire wall? if so does the fan in the cab work?

As far as the engine is concerend, so the fan dosnt work and you have replace the thermostat. we know this.

the water pump would be first thing to check. it typicly makes a whining sound and leaks down the back of the engine on the drivers side so Is it wet or do you have any unusual sounds comming from that area?

there are a couple of different sensors invovled with turning the colling fan on. looks like its time to back track and pinpoint witch one is bad

I agree the no heat issue is probably still due to the heat duct as I had suggested before, what’s the deal kdawg do you have a duct there or no? He did say it was ‘blowing cold air’ so we know the fan works.

Are you certain it could be the pump? Remember he has ‘no leaks’ and the temp will slowly fall at idle and raise while moving. I would think that if it was the pump, the engine would overheat in both scenarios. I’ve experienced this problem before except that my rad fan was working. I discovered the problem when I saw my overflow tank had bubbles while the car was running.

I see it as simple physics, but I would like to hear the pump cause I’m intrigued by this problem :slight_smile:

Did you bleed the cooling system after installing the new thermostat? If there’s air trapped in the heater core it can prevent coolant from circulating through it. No circulation through the heater core equals no cabin heat. Air bubbles in the system can cause overheating too.

i had the system bled today and still no heat and it overheats, but the guys at Jiffy Lube think that the thermostat is bad. They also said that the head gasket looks good and the water pump looks like it is brand new.:hmm: