Exhaust in my coolant 22RE?

[ramminyota]

I have a 93 4runner with the 22re, the other day and off and on it would start with eratic up and down idle, it looked to be the cause of non-sufficiant flow through throttlebody, so after going through the system and even changing the thermostate, radiator and even pulled off the water-pump to inspect, all is good. but i notice after running a while before the idle issue starts, the system gets really pressured up. i think this causes the water pump to not work efficiant against the pressure...no coolant anywhere in oil or vis-versa...could this be a head-gasket issue and leaking exhaust into coolant, doesnt seem to burn any coolant either... head cracked?

 

[turboSR5]

Take the cap off of the coolant overflow/reservoir and sniff it. If it smells like a spray paint can then you can bet that the exhaust is leaking into there.

 

[ramminyota]

Seems okay, just so much pressure build up...and then the heater blows luke warn and the rad stays cool as if no flow, once you crack the cap and vent a bit the hotter coolant rushes to the cap area and then you see some heat on the rad...I just tested the thermostate in micro-waved boiling water and it opened perfect....

 

[bulldogtaxi]

the heater core could be clogged up or rotted inside

 

[ramminyota]

I will by-pass it and see what happens...going to look into the routing and see if it would stop flow around the system. thanks for the tip...

UPDATE:Well as it looks it should not interfere with the flow of coolant through the engine so i will rule this out for now.

 

[prowler]

Sounds a lot like a head gasget to me. I just went thru the same thing, and thats what it was. Cooling system would pressure up, blow hoses, bypass, rad cap etc etc. I would say almost for certain that is what has happened..