Hey all.

This has all of the makings of a manifold crack or leak, but I thought I'd ask anyway, to see if anyone has a different opinion or experience.

I started to notice the noise over the past couple of weeks, it's especially pronounced when I'm accelerating at anything more than 1/3 throttle.


So, what say you, LRF commentariat?

- H.

 

have someone hold a rag over the exhaust while you feel around under the hood, the back pressure should blow out somewhere.

 

First thing I would do is use a 12 point 13mm socket and see if you can snug any of those bolts near the noise.

If that does not work -
you would want to replace the exhaust gaskets from manifold to cylinder head.

I am betting snugging up the correct two bolts will work.

 

RacerX, you figure out what the issue was?

 

Another less painful approach is to hook up the outlet side of a shop vac to the exhaust then look for leaks using a spray bottle filled with soapy water. With the exhaust cold you won't have to smell your burning flesh plus it will probably leak more than it does when it is hot and expanded.

 

Yeah, that's if the heat doesn't sear my skin first. Think I might try another approach.

I tried this, they were pretty snug. That said, I didn't want to just crank away on them, as I didn't have any spares handy if one snapped.

This idea. I like this idea better.

I've been slowly collecting the parts needed to look into this, as I don't have a place to let the truck sit for days on end should the problem be a cracked manifold. I should have a replacement manifold in another few days along with all the gaskets, etc. I'll pull the manifold, and if it's just a gasket I'll sell the spare on eBay. If it's a crack, then I've got a spare ready to go in!

I'll post up with the results when I make the repairs.

 

Thanks for the update. I'm chasing an issue that might be related.

 

I had a similar sound. I let the truck cool overnight, started it and stuck my hand down there to see if I could feel anything. This only takes a few seconds, you don't have to worry about burning your hand.

Sure enough I felt air coming out between the head and the block at the # 6 cylinder. I hope this isn't your issue but with the motor cool you will have no problem finding your issue.

 

04duxlr, your idea wins.

I found the leak, between the y-pipe and manifold, it would seem that the gasket has blown out there.

 

I have the same problem but I used the seafoam induction method to find my leak.. Nothing like getting a face full of smoke when your head is under the bonnet! Should I install the new gasket as it came (just bare metal) or add some sort of sealant to the new metal gasket?