Rattle when in boost

R

rickbtbird

Registered User
I have this rattle noise thingy that I only here when I'm getting on it a bit. If I put the engine in boost something starts to rattle. I can't tell where it's coming from but it sounds almost like an exhaust after burn noise. If I park the car, open the hood and rev the motor I can't hear it. If I get in the driver's seat and rev the motor I can't hear it. If I shift through the gears and go into boost I can hear it. It just started happening recently. So I filled the tank full of Sunoco 93 and it's still happening. I haven't been under it yet. Maybe I got some loose marbles in the blower.. or the there’s a loose bracket somewhere. For sure it I only notice it if I go into boost. I’m stumped.
 
check your starter solenoid.... the two bolts holding mine on were loose and it was making a metallic rattling sound, eventually led to my starter being rendered inoperable.
 
Might give it time to flush the previous fuel load - wonder if someone is selling Valero 87 as Valero 93... :)
 
What year & trans?

I believe there was a TSB that mentioned manual trans noise affecting the knock sensor.
 
Could be pinging...

DOes it resemble anything like a heat sheild rattling?

Both make rattling type sounds both very different in that type of sound..I mention it because this is somthing Im experiencing
 
also for it to suddenly do that..If it is pinging check fuel pressure if at all possable. EVen if it goes away with pulling the octane plug you probably have something going wrong fuel wise
 
I think it's more or a mechanical thing because it sounds like a loose bolt inside of a pipe. I know what pre ignition sounds like. This isn’t it. I'm starting to think I got something going on with my 5speed tranny or shifter or clutch. Hopefully I'll be able to get under the car this weekend. I can barley hear it when I rev the motor but under load and when I get on it it's louder.
 
many things it could be ...many things it may not be ... motor mounts letting the oil pan rub on cross member/kframe...My best guess would be ...heat shield on cats thats what happened to mine ... and only under load ....and I couldn't weld the stainless back on to the cat ..likely due to my lack of skill welding stainless steel .. so I wrapped it in stainless gear clamps ....dave
 
MercsSC1 said:
many things it could be ...many things it may not be ... motor mounts letting the oil pan rub on cross member/kframe...My best guess would be ...heat shield on cats thats what happened to mine ... and only under load ....and I couldn't weld the stainless back on to the cat ..likely due to my lack of skill welding stainless steel .. so I wrapped it in stainless gear clamps ....dave
Click to expand...

Motor mounts are new, Cat's are SPC and also new.
I can hear it now in the wheel well if I rev the motor as I stand by the engine bay. Sounds like a piece of metal vibrating against another. It’s much louder under load.

It's raining like mad here right now so there's no working on it this weekend.
 
New SCP Cat is Root Cause

Last year I had my exhaust guy put two new high flow SCP Cats on this car. After it was done I think I put maybe 2500 miles on it before the driver's side cat started rattling. It sounds like it come from within the cat. I'm wondering what made that happen :confused:. I never had this issue with my 90 and it had the same exact cats.

I'm going to take in to my exhaust guy next week. Does anybody know of some quality cats they've been using for a long period of time?
 
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