can a compression leak put gasses into the coolant?

[754bigbore]

Not sure whats going on with the sled but now I get foam in the coolant reservoir. originally I thought it may have been some varsol, etc left over when I put the fix kit in. Now I am thinking I might have a leaking o-ring on the head or a leaking base gasket. I know a leaking o-ring on the head can leak internally as well as externally but not sure if a leaking base gasket will push gasses into the coolant. I had it running today and let it idle till it got to about 118 degrees then shut it down. Seemed to be steaming more than usual, but it was close to -20 also. Pulled the cap on the coolant tank and got some bubbles come up into the tank from down below. Inside the exhaust pipe is all grey and sludgy, never seen anything like that in any sled I have had. Any ideas? I do have a really fat map loaded in the PC5 not matched to the ecu flash, maybe that is the reason for the sludgy crap in the exhaust.Sorry- the heading should say"can a leaking base gasket cause compression leaks?"

 

[Minus40]

A leaking base gasket will not pressurize the cooling system, an o-ring will. grey and sludgy exhaust can be a sign of water or coolant mixed in. Just make sure it is not just condensation or spilled coolant in the pipe which will burn out when you drive it. Pull the plugs and check for clean piston top and plug, that will be the one pulling in coolant. Not so easy with a brand new top end however you should see something different. O-ring or base gasket can be the culprit, head has to come off either way so check those o-rings carefully first.
The little bit of extra fuel in a fat map is not the problem.