4.0 SOHC - Head Gasket Question

[Dan2002]

Hey All,

I have an 02 with 97k miles (4.0 SOHC), and noticed a faint coolant smell/small leak near the front of the passenger side of the engine. A shop looked at it and said that it seems to be the head gasket and it's a big job. No coolant in the oil, and I've been keeping any eye on it for several months now. In colder weather it didn't seem to be leaking at all. Is it normal for a head gasket fail to behave like this?

TIA.... Dan

 

[RonD]

No, not normal for head to leak coolant externally.
Intake manifold gasket would be more likely, coolant flows from one head to the other thru the lower intake manifold.
And that is from passenger side front to drivers side rear.

Also don't over look hoses with pin holes.

I chased a front engine leak for a week, turn out to be upper rad hose with a pin hole leak that only sprayed out coolant after engine warmed up, when system had pressure.
Fine stream on to front of engine.
Hose had no sign of a leak
Found it when checking the engine hot, sprayed on the back of my hand, literally could not see it even after I knew it was there

 

[Dan2002]

Thanks for the info! I thought it was weird for a head gasket..... also I didn't know that coolant passes through the lower intake. That makes alot more sense than a head gasket.

Anybody else have thoughts on this?

Dan

 

[adsm08]

Coolant does not flow through the intake, nor is it sealed by any associated gaskets on the 4.0 SOHC.

Coolant in that area is often due to a failed thermostat housing, or gasket. It will leak coolant into the valley and it can run forward.

Also, I have seen head gaskets cause external leaks before, but it is very uncommon.

 

[Dan2002]

Thanks adsm08, the thermostat housing was replaced 3 years ago, I've only put about 12k miles on it since then.... but it still needs to be looked at. If it is a head gasket, would the coolant look bright green and clean? I thought it might be discolored.

Dan