Hello again all,
I know the fuel pump makes a ticking sound and i'm familiar with the TSB with it. My issue is a couple days ago a strange rattling sound developed and is only audible during the 1700-2200 RPM range. A buddy of mine and I took a look see and determined that it is not an exhaust leak and not turbo noise. We think it's the engine mounted fuel pump but we're not sure. I'm hoping that someone else knows what I'm talking about and can tell me a little more. Any suggestions? Passed warranty and it's an 08 SS 5spd. Thanks

 

If I had to guess, I would say that if its only in a certain RPM range, that the rattle is probably related to the engine twisting and a rubber grommet being loose. Its hard to guess but I would see if someone can listen with the hood open, because I would bet a small wager its the air box rattling...

 

Find "the engine mounted fuel pump" and you win the big prize. Hint: there ain't one.

I am betting that you missed the flex pipe leak, depending on how you ruled out exhaust leaks.

 

 

Correct JJfly.
It is usually called the high pressure fuel pump on the LNF engine.
If you think that's where the noise is, just have a friend run up the rpms while you feel the pump with your hand. If the rattle is coming from the pump, you should be able to feel/hear it when it hits that rpm range.
Caution: Just stay clear of any moving engine parts when doing this.

Fwiw. I would think it's something else as others have suggested.

 

Sorry donbrew, but us SS owners have 2 fuel pumps. One in the tank, and the high pressure cam driven pump just above the oil filter. The high pressure unit is for the direct injection system on the SS.

 

OK, never mind....

 

Don't feel bad Don, my mind is "Normally Aspirated" too, sometimes these boosted HHR's will throw you for a loop.

 

great now I'll have Mercury and Bowie singing Under Pressure in my head all day!! lol

 

Great now i'm really confused .. the rattle/crackle noise just stopped. HMMM??