Here's the situation:

When driving hard, I my 8 gets a raspy, growl (almost like it had phlegm in the exhaust) between 4 and 6K...then it kind of goes away.

The sound is definitely coming from under the hood and only under transmission load.

I am wondering about:

A. engine knock...but I run 91 (unless the corner gashop is getting funky).

B. A bad transmission...

C. Computer issue...

It has new plugs and new coils - 8K at least.

Any thoughts?

 

I'd get your mechanic to check out your muffler bearings.

 

Hmmm. Maybe you have a Timber Wolf stuck under the hood.

 

He said raspy growl! Timber wolf with a cold!

 

The muffler bearings are fine - they've been ported and chipped, too.

As for the wolf, it coughed up a cat.

")

 

Unsuccessful troll is unsuccessful

 

well played Wily.

Have you checked the cat converter to see if it has come apart internally? Sometimes it will and the ceramic material will get spread throughout the exhaust system making this sound weird.

 

what about when you are sitting at idle and rev it to 4-6k?

 

That reminds me of my old cat remember 9k

 

Do you have an aftermarket intake?

 

Try pre-mixing with some TCW-3 2 stroke oil(4-5oz with full tank of gas) and see if the issue noticeably quiets down. Could be a compression issue or lack of oil getting to the combustion chamber. Lucas upper cylinder lubricant could be used as an alternative to the tcw3 premix as a temporary test.

I searched high and low when I was having these symptoms and there were very few threads about this issue at the time.

 

Hey guys. First time posting. I am also having this problem, and have used the Lucas Oil upper cylinder (clear bottle) which successfully eliminated this noise. My thought is I am having issues with my OMP or lines connecting it to the engine. I did have a compression test done back in May, and it did not score very high on it, however, I seemed to have remedied that problem by using the Lucas oil engine cleaner (white bottle) to remove carbon buildup. The car ran great for a while, but this is a new sound which seems to have been remedied by using the Lucas Oil upper cylinder. This is what is leading me to diagnose the OMP. Thoughts? (Currently no CEL's present and car is not running in limp mode)