Hi guys,

I just replaced all six plugs with iridiums, put it back together started it up and am getting this god-awful high pitched squeal/scream in the engine bay, and an uneven idle :eeek: . It all went back together as it came apart (as far as I am aware) and the only thing I can narrow this down to is one of the short bolts attaching the upper and lower manifolds stripped the thread in the lower manifold.

Could a stripped thread in the lower manifold cause this? None of the belts were touched so I can't imagine it being drivebelt related.

(EDIT: I also noticed there wasn't an EGR->Plenum gasket when I reattached the pipe (not sure if there was one prior to this either), could this be contributing to the problem?


Thanks guys:happy:

Air rushing through a hole in the inlet manifold can cause a squeal, a little bit like a supercharger belt in my experience. lack of gasket would definitely be a potential to cause issues.

Air rushing through a hole in the inlet manifold can cause a squeal, a little bit like a supercharger belt in my experience. lack of gasket would definitely be a potential to cause issues.

It does sound like a supercharger belt somewhat, so I wouldn't be surprised if it was the case. I've got the both the upper and lower manifolds off just have to get a replacement one now and get new valley, plenum and EGR ->plenum gaskets

It was the stripped thread in the lower manifold. Sourced a used manifold off Unique Mits Bits (thanks Tony!) fitted it back up and it fired up no problems. The missing EGR->Plenum gasket doesn't seem to present a problem at this point.

Good to hear it worked out and was a somewhat easy fix.