Northstar Head Gasket

[BigCat83]

There was a platform change in 1998 for the Seville. The engine is pretty much the same for the 1997. There may be some differences in the way the engine cradle drops, the accessory mounting on the engine, etc. Others with experience with the 1998 and later Seville platform and FSM will likely chime in. I would go ahead and get the 1997 FSM and use it for your 1996 and 1997 Sevilles, which are almost identical.

I wouldn't even consider an attempt at a chemical repair on a Northstar because the head gaskets practially never give problems unless a head bolt pulls out, hence the TimeSert repair, which no chemical treatment is going to address.

To re-inforce Jim's comments about head bolts pulling out - that's the cause of my problem. Three headbolts on the rear bank were "finger tight" and the rest were loose. Clearly, a chemical head gasket repair was useless in my case. Pull the heads, install the Timeserts, replace the heater pipes and hoses on the back of the engine and generally service and replace everything else that should be serviced or replaced. And you should be good to go.