Turned the key on my 2002 MC SS, V6, 3.8L, and the Intake Manifold exploded.

Anyone ever hear of the Intake Manifold Exploding on a GM V6, 3.8L? It sounded like a 12ga shotgun. Fortunately no one was looking into the engine compartment at the time as they likely would have been killed given the amount of shrapnel from this explosion. Note that the explosion was powerful enough to blow off the oil cap, which is screwed on with very thick threads.

The vehicle was at my mechanics at time and in his forty years he'* not seen an intake manifold explode save for those residing on Top Fuel or Funny Cars.

Am advising NHTSA Chairman via USPS Restricted Delivery Mail (which, under Federal Law, can only be signed for by the Addressee which will ensure delivery to his direct and personal attention). Hoping this is not another attempt at GM trying to save a few cents (vis-a-vis The Ivey Memo where GM put the value of Human Life at just over two bucks, the Ignition Switch issue to save fifty-seven cents, et al).

Any input greatly appreciated.

Why was it in the shop?

Some 3.8'* were recalled for faulty fuel pressure regulators. The diaphragm would rupture causing fuel to enter the intake system through the vacuum lines. At best the vehicle would run excessively rich because of uncontrolled fuel ingestion, at worst the vehicle catches fire or in certain circumstances the intake explodes.

This is probably the 5th one I have seen on here that exploded. Maybe 2 or 3 more I personally seen in the junkyard the same way.
As already mentioned, its due to a faulty FPR.

Wow that FPR diaphragm must have leaking fuel heavily, to cause it to completely blow apart like that.
For members wondering about their FPR'*, here is a good video showing the FPR leak eventually.
You can advance the video to about 1 min 50 seconds to where the FPR is shown.
It starts spraying out fuel at 3:57.

Thank you, Jolly. In researching that recall you spoke of the affected engines were according to GM through Model year 2000 (in the case of the Monte Carlo). I am exhibiting identical symptoms and am waiting to hear from GM with respect to this issue. In the meantime I assume they are shredding any relevant documents and / or Memo'* stating "Hey, this isn't just through the 2000 Model year" using a DOD approved shredder. On a serious note, I have lost all respect for GM with the revelations over the Ignition Switch issue. As many as 303 people - Men, Women, Children - are now in their graves so those bastards could save fifty-seven cents on a switch and then hid that fact for a decade. And don't even get me going on The Ivey Memo (where GM put the value of a Human Life at just over two bucks).

For those who have not heard of The Ivey Memo, and while both the NY Times and the LA Times also have excellent articles on same, this article sums it up well:

The Ivey Memo: The Original Cold Document That Made GM Squirm

I saw the video today at the garage from the perspective of an outside video camera mounted to a concrete wall and approximately twenty feet up and fifteen feet back from the vehicle. Bearing in mind that the hood was closed and locked the concussion was enough to vigorously vibrate the camera when it exploded. Fortunately as mentioned earlier no one had their head in that engine compartment when the key was turned. The video will be on YouTube in short order.

The vehicle had been brought there due to it stalling.

Again, thank you VERY much for your assistance!

Best,

Lyman

Looking forward to it.

In the meantime, enjoy this 3.8 v6 explosion, likely from the same issue.

Yup, faulty FPR the cause for sure.
Dorman actually makes the upper intake with strengthened baffles, and the UIM also comes with a reduced diameter EGR stovepipe for issues with the EGR gases burning the UIM till it causes the coolant ports going into the throttle body to leak.

When you replace that UIM be sure to go ahead and replace your lower intake manifold gasket with the aluminum framed one, as well as replace the coolant elbow with the aluminum one.
Glad nobody was hurt when that exploded!

Makes me want to go out & buy a new FPR, regardless if I think mine is fine or not.

Stalling is one of the symptoms of a bad FPR....a small leak, is no problem on a cold engine......but on a warm engine, it can cause a stall, or a hard restart, because the engine is running too rich.....

The exact same series of events took place for us - winter, car sat for a few weeks, charged the engine and the intake plenum blew up into pieces and started a fire that we put out with snow.
This is a known Chevy issue - why is there no recall? It was our only vehicle.