Hi all! so I got a used motordyne plenum spacer the other day and I saw the preattached gasket was damaged so I took it off and made my own with RTV. I torqued it down to spec and waited 24 hours for it to cure and then reset my ECU and I try to start it up. When I start it up it makes an extremely loud pulsing screeching noise. Idk what it is and I am very concerned it also smells like gas when I start it up. I changed my belts not too long ago so I don’t think it’s my belt. I’m worried pls SOS

 

Sounds like you have a bad vacuum leak somewhere, and possibly a fuel leak if you smell fuel as well. Run the car and try to pinpoint the leak, spray some WD-40 where you hear the noise and listen for an idle change, or the noise to stop, that will be the problem area.

 

I did some more research I think it had to do with the ecu reset and the belt because after the 3rd time starting it up and letting it idle the noise disappeared completely and permanently. so my theory was that it was the belts making the sound.Thank you!

 

Its the spacer or the upper plenum gasket, trust me i would know , try putting the plenum back on and torquing to 65 INCH pounds, if not replace the gasket on z1 motersports or amazon.

 

double update it only happens when it’s cold and it actually sounds like it comes from my belt so Im gonna check the tensioner and then imma try the gasket thing

 

I have the Z1 plenum spacer gasket but I wasn't sure if it was safe to use bc it’s skinnier than the spacer but when I start up my engine when it’s warm it doesn’t squeal anymore, only when it’s cold any ideas with this info?

 

Well it could be that the metal warps into a sealed shape at a very small level? im not sure but i mentioned this https://www.z1motorsports.com/manifo...et-p-5371.html , gasket which is different for the one on the plenum spacer but just make sure everything is tightened right

 

if you search the part number from z1 and put it on amazon you can get it cheaper plus get a throttle body gasket and a intake port one

 

okay final update I fixed the tensioner when it was cold and then I started it and the squeak was gone so it was my belt! Thank you for the help