antifreeze in cylinder

[lewski]

I have a merc170 and have coolant leaking into the no 4 cylinder.Just wondering if it is the head gasket but the old one looked fine when I pulled it apart.Also could it be the riser gasket where it bolts on to the exhaust manifold.It has an aluminum exhaust manifold.

 

[stonyloam]

Re: antifreeze in cylinder

I have a merc170 and have coolant leaking into the no 4 cylinder.Just wondering if it is the head gasket but the old one looked fine when I pulled it apart.Also could it be the riser gasket where it bolts on to the exhaust manifold.It has an aluminum exhaust manifold.

Those are the two things to look for. The head gasket could be intact, but still leaking, mine was. Look for dark stains on the cylinder head or block where the seal may have broken. Look at the #4 spark plug electrode insulator, if it is white (vs tan for the other normal plugs) that would indicate coolant is entering the cylinder while it is running, not likely to happen with an exhaust riser leak.