Intake Manifold destroyed-replacing it

On engine start the intake manifold was destroyed by an apparent backfire.

-The starter is still good
-The engine can still rotate (removed spark plug wires to test)
-The intake manifold is now in several pieces
-I think I am missing a few parts that were tossed about by the explosion, so I still won't start it up after replacing the intake manifold.

What's the cause of this?

It did not get a new fuel pressure regulator with a certain recall from 5ish years ago.

There's a good chance it's because you didn't get the fuel pressure regulator changed. Don't keep trying to start it. Turn the key to the run position a couple times then pull the vacuum line from the fuel pressur regulator & check for fuel in the line.

There's a good chance it's because you didn't get the fuel pressure regulator changed. Don't keep trying to start it. Turn the key to the run position a couple times then pull the vacuum line from the fuel pressur regulator & check for fuel in the line.

The vacuum line didn't have fuel in it. I could smell fuel, but there were no apparent leaks.

I've completely removed the intake manifold and throttle body, and right now I am dealing with the coolant supply and return holes that go to the throttle body - I need to plug them up and clean up all the coolant.

Inside the intake manifold there was plenty of oil residue. Normal?

One of the intake manifold bolts was in bad shape, bent over 45 degrees where it held the manifold down - there was quite some force in the explosion.

What Year??????????

1. NHTSA Campaign ID Number: 04V090000
Recall Date:
2004-02-24

Summary:
ON CERTAIN PASSENGER VEHICLES EQUIPPED WITH 3800 V6 (L36) ENGINES AND CERTAIN DELPHI FUEL PRESSURE REGULATORS, THE REGULATORS HAVE A MUCH HIGHER THAN USUAL RATE OF FUEL LEAKS. A LEAK CAN ALLOW FUEL TO ENTER THE INTAKE MANIFOLD THROUGH A VACUUM LINE. IF THE ENGINE DOES NOT START WHEN CRANKED, THE FUEL FROM THE LEAKING REGULATOR AND A MISTIMED SPARK CAN CAUSE A BACKFIRE.

Consequences:
THE BACKFIRE CAN RUPTURE THE INTAKE MANIFOLD. THE RUPTURE OF THE INTAKE MANIFOLD CAN DISPLACE A FUEL LINE, PULLING AN INJECTOR OUT OF PLACE, AND CAUSING A FUEL LEAK AND POSSIBLE FIRE.

Remedy:
DEALERS WILL INSTALL NEW FUEL PRESSURE REGULATORS WITH IMPROVED DIAPHRAGMS. THE RECALL WILL BE CONDUCTED IN PHASED MAILINGS. PHASE 1 BEGAN ON JUNE 30, 2004, AND PHASE 2 BEGAN ON SEPTEMBER 30, 2004. OWNERS SHOULD CONTACT BUICK AT 1-866-608-8080, OLDSMOBILE AT 1-800-630-6537, OR PONTIAC AT 1-800-620-7668.

Component Affected:
FUEL SYSTEM, GASOLINE DELIVERY

Potential Cars Affected:
910,873

Notes:
GENERAL MOTORS CORP.

By the way, General Motors knows all about this defect, because they sell a ton of these replacement manifolds.

I'm aware of the recall. So was the dealership when I called them up about the recall. They still rejected the idea that my car would have been affected like that. Flat out refusal.

Oh, and the main thing: they say the recall has expired and that it won't be performed at no cost, unless it can be determined that the FPR caused the damage. I say, well, can you tell? and they say -we gotta look at it- I say -who's towing it?- and so on until I say GFYS.