[what_is_dsm]

I'm new in the DSM scene. Recently I bought myself a 1990 Plymouth Laser FWD turbo. Everything is good on it except a leaking valve cover gasket (piece of cake to replace for me).

But I have another prob with the engine. At about 5000 rpm, especially when i shift at those rpm's, the car makes a strange sound which sounds like a metal grinding noise. But it also sounds like metal vibrating. I've heard of 1g cars having some probs with loose exhaust heat shields or something. Is there anything else that could be causing this strange noise????
It's hard to locate where it's coming from.
It doesn't matter if i'm driving OR idling but always around the 5000rpm mark

PLEASE HELP !!!

 

[what_is_dsm]

anyone?

 

[AluH20]

Just a couple things I need to try to get a picture here:

{1} First try to pinpoint EXACTLY what the noise is similar to:
Is the noise like a "THUD" lasting about a second or less?
-OR-
Is the noise like a "Rattle/Clank/Shaking" that lasts for a few seconds (or however long you remain at the 5,000 RPM mark)
-OR-
Is the noise more of a Vibrating "I can feel a slight massage" noise?



{2} Then try your best to actually locate the problem area:
Is this noise coming from the engine (you can hear it basically behind your dashboard up in front under the hood) -OR- is the noise coming from say... the middle area of the car? or the rear of the car (towards the back seats)?



{3} Then re-enact the problem and see if it is less severe under different conditions:
If you sat at an idle (car is in neutral) and slowly brought up your RPM's to the 5,000 RPM area... will the noise happen?
-OR-
Does the noise ONLY happen that strong when you're rolling/driving?

I know you sort of already answered these questions, but I'm just trying to narrow it down (get a little bit more info, right now it's kinda broad and could be a few things).

P.S. All cars *can* develop rattling heat shields. It depends on how rusty their exhaust system is. My daily driver Camaro (I've had for 2 years) and it developed a rattling heat shield... I just ripped the shield off (I figured if I ran a 3" catback anyways the shield wouldn't be there).

 

[talonkid119]

sounds like it could be a heat shield. Get under the car and wiggle some of the heat shields around to see if there loose. i have noticed that the one above the cat seems to raddle some times or the one on the downpipe, jack it up and check it out.

mike

 

[AluH20]

When I had a heat shield problem w/ the car I mentioned above, I noticed that it would rattle at 1,000RPM and ONLY 1,000RPM. Any less or more (driving or idling) it would go away. So I clipped it off.

How rusted is your exhaust system?

 

[what_is_dsm]

Hey guys! I found the problem today; it was the bottom heat shield from the cat. I ripped that $hit off......now it's fine.

Thanks for all the help...
Respect hardcore..