Coolant in exhaust

[vandor]

I just looked at a friends Spider 2000. Engine rebuilt about a year ago, runs well. Suddenly there is coolant coming out of the exhaust. Remove plugs, pressurize cooling system and we see coolant in #4 cylinder. Run a compression test, all cylinders are ~190psi. Run a leakdown test on #4 cylinder, and there is no air getting into the cooling system and leakdown is only 3%.

I am thinking its either a cracked head or somehow coolant is getting into the intake from the intake manifold gasket (bolts are tight).

Any other ideas?

[131]

I've had similar symptoms, only after it was warmed up, car ran fine, but from behind it looked like the smoke screen from the bat mobile. It turned out to be a crack from the water gallery into an exhaust port.

[carl]

I have had this happen a few times and it was coolant leaking from the intake manifold to the #4 intake runner. The coolant port from the back of the head is very close to the # 4 intake runner and if there is a problem with the gasket seal for the intake manifold you will get coolant in #4.

carl

[redcars]

I had a ford ztech engine in my Super7 do this and it was a crack in the exhaust port letting coolant leak into the exhaust. This head was ported with 11 years of competition use. I do not think a stock head would do this.

[DanD]

I see that the problem isn't what is causing the leak, it is how to proceed.

Changing the intake gasket might solve the problem, but it is a gamble. I'd probably pull the head and look at everything.

Or else I would replace the intake gasket and hope for the best... I use Blue Hylomar on a lot of these gaskets nowadays. Genuine space age technology, I honestly believe it helps your chances of getting a good seal under marginal or extreme conditions. And it actually comes apart cleaner than a dry gasket.

Of course I am like a walrus at a tupperware party. I'm always looking for a tight seal.
In the end, once you bite the bullet, the rest is easy.

[vandor]

My plan is to pressurize the cooling system for a while then pull the intake manifold. If there is coolant in the intake port then there is a good chance it's the manifold gasket.
If not then I'll pull the head and have it pressure tested.

[So Cal Mark]

I'd remove the spark plug, turn the motor until the #4 intake valve is open, then pressurize the cooling system. If you get coolant in the cylinder then, you can figure on an intake gasket. Do you have a boroscope to look into the cylinder?

[vandor]

I did that, turned the engine over with the system pressurized, but the results were inconclusive, ie no big gush of coolant at any particular point.

[djape1977]

first replace the intake gasket

heads on fiat twincam very rarely crack, i'm yet to see one that has cracked in person, after 17yrs of fiddling with 124, 125, 131, 132...

head gasket usually fails on cyl 2 or 3.

check the torque of head bolts. if ones near cyl 4 are undertorqued, than it's probably head gasket.

[DanD]

Any Progress ?