When my car is idling and starts crapping out trying to die sputtering and such, I hear a VERY distinct rattling/clanking coming from what sounds like 2 feet in front of my feet on the bottom of the car. It sounds sort of tinny, I don't know how to describe it any better, any help would be GREAT!

--Fritz

 

heat shields.

 

mine made a distinct clank sound once. i think it lost a seal. car is considered dead and sitting...
anyways, enough about me. i would check the heat shields and make sure they have their bolts and are tight. i had a gsr that made a horrible clanky metallic sound at a certain rpm. it ended up being a problem with the exhaust manifold. certain rpms just carry a certain vibration that wiggles some things the right way.

 

Probably the heatshields or an rpm dependent resonation. I think at 300-600 rpms everything will shake violently as the engine struggles to stay running. If you rev it up and hold it idle does it still make the sound?

 

Well if I bump the rev's it does it also at about 1.2k rpm, now if it is the heat shields that leads me to another question. Recently my turbo has been acting funky. It won't boost properly everyday. Could the heatshields have something to do with my exhaust system being clogged or something causing my turbo to not spool correctly?? One time the turbo made a whining noise and only spooled half way, the next time it made a whooshing of air noise and no boost past atmospheric, and then the most recent time it only built up to 1/2 boost. Think the heatshields and exhaust might be the culprit? Hopefully I can kill two birds with one stone on this.

--Fritz

 

heatshields don't (or shouldnt) even touch your exhaust. i don't know how they could have any effect. your turbo may be bad, though.

 

Disclaimer: I Don't know anything about turbos.

However, Turbos are just another mechanical system, and it sounds likes your bearings are starting to go to me... I'd do the check, where you see how freely it spins and if there is any play.. I know i read over it in the FSM one time...

 

Worn turbo bearings = impeller wheel touches housing = tink tinkety tink.

 

Meaning rebuilt or purchase another turbo?

 

When i installed my header i cut alot of heatshield mounts, the pulse from the exhaust makes everything rattle like mad at idle.

 

Well all sorts of stuff rattles on my car but it is much less noticeable and much more monotonous it is very intermittent, and I have noticed it happens most when my car is about to die and then it catches itself momentarilly boosting to correct. Thus I think that impeller wheel theory may be the closest to correct. How do I inspect the impeller wheel, open up the TID and check for play? If so where exactly is the TID I looked in the FSM and couldn't find it and I couldn't find links to pics of it searching either.

--Fritz