Answer

Depending on the expertise of your mechanic, replacing the front head gasket may be a less expensive option.

If all three front cylinders lose compression, it is likely that the gasket has failed on that side of the engine. Pontiac had two flavors of V6 engine under the hood - if your vehicle has the 24-valve DOHC version then it is a very complicated procedure, and on top of that the replacement engine is not as readily available as any standard OHV V6.

At any rate, disassembling the front bank makes a lot of sense, because at that point you will know for certain if your engine should be replaced instead of a gasket or just the head itself. Replacing BOTH head gaskets is always recommended, but if you find that only one gasket has failed and you are extremely hardup for cash, replacing just one gasket will be the cheapest repair you can attempt. Most technicians in the field are admittedly more enthusiastic about replacing an engine than attempting to go inside one to repair it. Logically, replacing the entire engine can be considered unnecessary if an economical repair is possible.

Edited by classictech on 6/16/2008 at 2:23 PM