Cadillac STS-V Series Forum Discussion, Head gasket question in Cadillac V-Series Forums; After perusing the technical forum and seeing a 20-mile-long thread on Northstar head gasket and head bolt issues, I started ...
After perusing the technical forum and seeing a 20-mile-long thread on Northstar head gasket and head bolt issues, I started wondering about the STS-V.
It appears to me that at least part of the Northstar head gasket problem might be with the gasket itself, which appears to fail after 80-100,000 miles of trying to maintain a seal against the high expansion coefficients of an all-aluminum engine.
In the recent Car & Driver, it is mentioned that the new, supercharged 'vette ZR-1 has a 4-layer gasket rather than a 2-layer gasket to help cope with the stress.
Anyway, I'm wondering if Cadillac did a similar upgrade on the Northstar in the STS-V? I know they reduced the bore to make the block stronger. Coming up with a whole new set of pistons and new block casting is pretty hard core. The resized block would need a resized gasket anyway, so why not upgrade while you're at it?
I wouldn't worry about it. We have only ever seen 1 failure on this site in the newer (2004+) RWD Caddys, and the engine only had a few thousand miles on it so there was clearly a manufacturing defect.