2002 Buick Lesabre Engine Explosion

I'm also trying to understand pressure inside of the engine so intense that it would blow off a tightly fastened oil cap and make the heads leak oil through the gaskets. Any idea on that?

So I guess the bottom line is tow it somewhere, have it looked at and see if it's salvageable? Or do you think a new engine would be more cost effective?

The car is in excellent condition, physically speaking, both inside and out. I bought it for an elderly uncle several years ago and he passed away last week. I got in the car to start it up because I intended to take it back and keep it as a second car, but now I'm wondering if it's even worth the expense. I understand the GM 3.8 from 1996 through 2005 had a plastic intake plenum prone to failure and I wonder if this might be the cause of this entire problem, I just can't see how the intake failure would create so much internal pressure as to bust off the oil cap and make the head gaskets leak. I'm also not sure what other damage has been caused. It's hard to tell.. Probably not worth investing the money into it, but a shame nonetheless because of how pristine the car is.

i have a 97 lesabre and the fuel pressure regulator failed causing the intake and all cylinders to fill with fuel. lucky for me it hydrolocked. i removed the intake plenum and sucked the fuel out of the intake ports. i also removed the spark plugs and cranked the engine over to remove the fuel from the cylinders. if it had tried to start it would have caused a huge explosion. this may be what happened. i can certainly understand leaking head gaskets and the plastic intake blown apart. if you replace the engine make sure to replace the fuel pressere regulator on the fuel rail or it will happen again. that would suck!