mudjnky

I have a 1996 4Runner with the 3.4. We bought it a few months ago and it has no heat. We have covered all the basics and they are good. There is no coolant flow to the heater core. you can run the truck with the hoses disconnected and only a little leaks out. The engine was replaced at some point not too long before we got it. Is there possibly an engine gasket that was installed backwards that is blocking the flow? I am not familiar with these engines and any help is greatly appreciated. A friend suggested that possibly the intake gasket is incorrect, but I'm hoping someone hear can give a definite answer. Thanks in advance!

Green_slime

was the engine replaced or rebuilt if replaced i doubt any of the gaskets are installed wrong try cleaning the hoses out they might be clogged

Tofer

take a garden hose and flush the whole system....

mudjnky

The system has been completely flushed, nothing externally is clogged, not sure if the engine was rebuilt or replaced, but probably replaced with a long block

Green_slime

if it was a long block the chances are slim that the factory screwd up ya it happens but not often does it overheat at all

mudjnky

It does not overheat, just no coolant flow to to the heater hoses. Even pulled the water pump off to check that and it was ok.

raydouble

I bet the level is low or you have a air bubble.

Open the heater valve, take off the radiator cap, warm up.....add missing coolant.

Are you sure the engine is warming up all the way?

brian2sun

Ya, I would guess air bubble or blocked passage. Could be a HG issue - hopefully not.

FogRunner

Bet way to get air out the cooling system and heater core is to drive the front up on ramps or put it up on jack stands.

Take off the radiator cap and start it up and let it run with the heater on full. Every couple of minutes rev the engine up quickly and that will help jolt the air bubbles out of the system.

Just be sure to keep an eye on the level in the radiator because when that air bubble passes and coolant fills the heater core the radiator can drop a good couple of inches.

I had the same thing happen after I replaced the radiator and t-stat on my 02 runner.

Also be sure to check the heater water valve on the firewall directly in the middle of the firewall above the engine. When you turn on the heater the cable should pull the arm and open the valve. This is a common item to get broken during engine swaps.

FOG

mcshurley

I have a 92 4runner and the heat stopped working today. The coolant is full, the temp gauge is normal (not over heating) but there was gurgling sound sometimes when I was accelerating.

Any ideas?

raydouble

Air pocket in system......where are you leaking from?
or
Clogged heater core.

Same

mcshurley

I don't think its leaking anywhere but I'm also not very car savvy.

How does one fix a clogged heater core?

Thanks

raydouble

You can try flushing it, but it usually means replacing it.