This summer I picked up a 1993 4runner with a 22re that was not starting. I initially assumed it was an electrical issue and spent some time troubleshooting that. After replacing the spark plugs/wires/distributor cap/rotor it started but idled rough, put white smoke out the exhaust pipe, continued to smoke and then died after a few minutes. Was able to restart it and have the same experience a few times. Assumed it was most likely a head gasket due to the smoke and rapid coolant consumption, so I ordered a head gasket kit and started tearing it apart.

There does not appear to be any oil or coolant mixing and I found some liquid that appears to be coolant (kind of hard to tell) in the intake manifold during disassembly. I read few threads about the IACV going bad and leaking into the throttle body/intake but couldn't find anything conclusive... So the question is:

How often does a blown head gasket leak into the intake manifold but not the oil?
Is there another way for coolant to end up in the intake?
How can I be sure if it's the IACV, or not?

I'm almost ready to pull the head (manifolds off etc), but it would be a shame to do so if the problem lies elsewhere.

 

Bad lower intake gasket can cause coolant to enter the intake, and then out the exhaust.

 

Interesting... I was wondering if it might be something like that, just wasn't sure if there were any coolant passages in that area. I'll have to pull the lower intake and take a look. Thanks!

 

if your are pulling the head, just leave the lower intake on, and pull both at the same time. Lots easier to pull the intake off and install when it's on the work bench.

 

There is no need to pull the head if the intake gasket is the problem, but you can follow snippits advice if you have to pull the head.

Based on your symptoms, it sounds like a lower intake gasket is the issue.

 

Blue lines pointing at coolant ports on lower intake gasket.

 

Thanks for the input. I haven't had much time to work on the car lately, hence the late reply...
Tried replacing the intake gasket, still the same symptoms. Did some more investigation and found that their was some coolant in the oil after cranking it for a while. Pulled the head today and found two separate cracks, so now I'm pricing cylinder heads... Oh well.

 

Don't discount the iacv isn't an issue, you found something that maybe coolant in the upper intake. There are three ways it could have got there, that I can think of off hand.

Steam boiling over from the coolant expansion/overflow can get sucked back into the VAFM.

Coolant in the EGR system, there is the EGR coolant plate as well as a direct path from the exhaust.

And finally the IACV contains a well known coolant path.