I have an 87 4runner with a 22re. The engine was rebuilt with a new head at 246,000 miles and it now has 293,000. Recently the radiator has been boiling over into the overflow tank and spilling out the top because my overflow tank has no cap on it. Everytime I check the coolant level it is low. There doesn't appear to be coolant in the oil but it is going somewhere. Even when the coolant boils over the temp guage never goes up more than about half way and the engine doesnt seem to be getting any hotter than normal.

Also, the heater has not been working at all leading me to think there may be a heater core leak. When I checked all the hoses the radiator top and bottom hoses are hot, but when I check the heater core hoses only the hose going into the heater core is hot, and the one coming out feels like nothing is flowing through it.

Could this all be caused by a heater core leak? Or am I more likely looking at a head gasket leak? Or could it be both?

Any ideas or suggestions? Thanks.

 

If the headgasket is blown the water will not circulate because the compression is much higher than water pump pressure. Your temp guage is probably only reading air temp, the water isn't getting to it.

 

if you have a heater core leak, your floor board should be wet on the pass side. sounds like you have a clog or an air bubble somewhere. have you tried burping it, flushing it?

 

check the thermostat

 

The thermostat was replaced when the engine was rebuilt so that should still be working I think.
I flushed out the radiator but not the heater core, so Im thinking that should be my next step.
How do I burb it?

 

fill the radiator with coolant, leave the cap off radiator, start the engine, turn heater on, start squeezing hoses pushing air into the radiator, squeeze the heater core hoses and occasionally revving the engine. if you are successful, all your hoses should be hot, heater should be hot, normal operating temp. if not successful, you probably have other issues. get a new overflow cap, radiator cap, and make sure you use 50/50.

 

No leaks! and i would prob say your heater core is clogged, if it's been like around here it's clogged with ice and the idiot's couldn't keep coolant in it due to a upper rad hose being "Loose"
which the straight water brakes the rad after a good 4 day's ar 10-25degree's. even being ran... gave the water pump some shaft play, i didn't know they were ice crushers...



any ways. 50/50, make sure your heater core valve is working properly. and and worst pull the line's off and put a hose on and confirm it's clogged....

 

Yesterday I flushed out the heater core. I didn't see too much gunk come out but a little coolant came out then it ran clear water. I hooked everything back up, topped off my radiator and drove around the block a couple miles and after about a mile I started to get heat but it still never got too hot. When I got home I checked and I was missing coolant again and the passenger side floor was a little wet and there was some splattered coolant around under the glove box so now Im thinking its a heater core leak for sure.

Im going to try to replace that tomorrow and hope that solves my problems.

Any suggestions on where to get a decent heater core that isn't going to run me too much money? The OEM ones I found were all around $300 and that seems a little high.