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?

Did they and if so, what is the difference?

We'll find out in the long run...or I will, since I bought my car, most of you seemed to have leased.

2000+ FWD Northstars have dramatically fewer instances of HG failure.
2004+ RWD Northstars are 80% new, and the SC versions are even stronger, so I suspect its a total non-issue.

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.

davidstan had one

was it on an STS-V?

davidstan had one
yes my first sts v blew the head gasket after i think 1200 miles or so. Dealer gave me new car so no problem. I'm pretty convinced it was rare.