Help! Sounds like somthing loose rear of engine compartment

[JOHNNYB]

IT SOUND LIKE SOMETHING IS LOOSE AT THE REAR OF MY L98 ENGINE COMPARTMENT. SOUNDS ALMOST LIKE A UNSTEADY RATTLE OF METAL ON METAL NOT TO LOUD ONLY WHILE CAR IS JUST IDLING. IF I HIT THE GAS IT STOPS AT LEAST UNTIL CAR IS BACK AT IDLE OR IF I MESS WITH THE SHIFTER IT WILL STOP FOR A ABOUT 1 MINUTE BUT EVEN AT IDLE ITS NOT CONSTANT. ITS LIKE EVERY 5-15 SECONDS IT WILL RATTLE A FEW TIMES.WONDERING IF IT IS POSSIBLE THAT THE CLUTCH HOUSING IS LOOSE OR MAYBE TRANSMISSION IS LOOSE? CAR HAS DONE IT SINCE I BOUGHT IT 2 YEARS AGO BUT I NOTICED TODAY THAT IT HAS GOTTEN A LITTLE LOUDER

THANK YOU

 

[John Robinson]

IT SOUND LIKE SOMETHING IS LOOSE AT THE REAR OF MY L98 ENGINE COMPARTMENT. SOUNDS ALMOST LIKE A UNSTEADY RATTLE OF METAL ON METAL NOT TO LOUD ONLY WHILE CAR IS JUST IDLING. IF I HIT THE GAS IT STOPS AT LEAST UNTIL CAR IS BACK AT IDLE OR IF I MESS WITH THE SHIFTER IT WILL STOP FOR A ABOUT 1 MINUTE BUT EVEN AT IDLE ITS NOT CONSTANT. ITS LIKE EVERY 5-15 SECONDS IT WILL RATTLE A FEW TIMES.WONDERING IF IT IS POSSIBLE THAT THE CLUTCH HOUSING IS LOOSE OR MAYBE TRANSMISSION IS LOOSE? CAR HAS DONE IT SINCE I BOUGHT IT 2 YEARS AGO BUT I NOTICED TODAY THAT IT HAS GOTTEN A LITTLE LOUDER

THANK YOU

Let me guess it is a manual transmission. Today the weather was nice maybe and you pulled up to a drive up window and put the window down and put car in neutral and you heard it. Just guessing here but it sounds like a classic throw out bearing rattle. GM had a problem with some models doing this and eventually eliminated it. In your case I would not worry about it especially if everything is working normally. Sometime in the future when you replace the clutch the replacement part will be an upgrade and the noise will be gone.

 

[JOHNNYB]

Let me guess it is a manual transmission. Today the weather was nice maybe and you pulled up to a drive up window and put the window down and put car in neutral and you heard it. Just guessing here but it sounds like a classic throw out bearing rattle. GM had a problem with some models doing this and eventually eliminated it. In your case I would not worry about it especially if everything is working normally. Sometime in the future when you replace the clutch the replacement part will be an upgrade and the noise will be gone.

YEAH SHE`S A 6 SPEED:cool, BUT IT IS LOUD ENOUGH TO HEAR FROM A FEW FEET AWAY AS WELL AS IN THE CAR.THE CAR ALSO DOES IT WHILE ITS IN GEAR WITH CLUTCH PETAL PRESSED, COULD IT STILL BE THROW OUT BEARING?

 

[tmkassin]

Could be a loose shroud on a cat. Could also be the innards of a cat have come loose and are rattling.

 

[JOHNNYB]

could be a loose shroud on a cat. Could also be the innards of a cat have come loose and are rattling.

good thought ill check the shroud didnt think of it becuase i just replaced from the cat back last year

 

[boomdriver]

Thats my bet as well....broken cat guts. I've had it happen.

 

[Txbobcat]

Three votes for the cats

 

[T.M.808]

dude, i have the exact same sound. Only notice it when i'm in a drive thru and sound is bouncing off the wall. My exhaust is pretty loud. My car is an auto though. I also don't have any cats or resonator. So it's not that. This weekend, i'm putting my car up on ramps (pain because the car is lowered 2 1/2 inches), and check all the heat shields and bellhousing cover. The sound is not constant with the rpms, but as you say,goes away as soon as i touch the gas. I think a shield is vibrating against something. Will update this weekend.

 

[JOHNNYB]

dude, i have the exact same sound. Only notice it when i'm in a drive thru and sound is bouncing off the wall. My exhaust is pretty loud. My car is an auto though. I also don't have any cats or resonator. So it's not that. This weekend, i'm putting my car up on ramps (pain because the car is lowered 2 1/2 inches), and check all the heat shields and bellhousing cover. The sound is not constant with the rpms, but as you say,goes away as soon as i touch the gas. I think a shield is vibrating against something. Will update this weekend.

THAT SUCKS TRIING TO GET HER UP ON RAMPS I HAD TROUBLE WITH MINE TOO. I JUST USE STANDS NOW TAKES A LITTLE LONGER BUT I KNOW IM KEEPIN MY BUMPER IM GONNA LOOK AT MINE TOMORROW WILL UPDATE AS WELL

 

[T.M.808]

Hey Johnny,just as i suspected. Jacked up car,on the driver side near the floor board,theres a heat shield. It has 2 brackets rivited to the body of the car. My rear bracket has broken the rivets,so the rear section vibrates against the body or exhaust at certain rpms.

 

[JOHNNYB]

Hey Johnny,just as i suspected. Jacked up car,on the driver side near the floor board,theres a heat shield. It has 2 brackets rivited to the body of the car. My rear bracket has broken the rivets,so the rear section vibrates against the body or exhaust at certain rpms.

COOL MAN THANX FOR FILLING ME IN THAT'S GOOD ITS SOMETHING MINOR STILL HAVEN'T GOT TO MINE YET IM THINKING TOMORROW. HOPEFULLY MINE IS JUST A SHIELD TOO. ILL STILL POST WHEN I FIGURE IT OUT.

 

[Paul Higg]

I had the same exact problem on my C4.

Loose CAT shields.

I used safety wire to secure them as those rivets are steel and I had no way to put new rivets in without removing the entire exhaust.

 

[Radar]

I have read in other posts on this site as well as others that a dual mass flywheel can develope this noise too. I think the 6-speed in those early 90's years did have the dual mass flywheel.

If it was me, I would live with the niose until having to tear it down to do a clutch and then deal with it.

Radar