Not a huge issue but, when I start up the truck after its cooled off it doesnt do this, but after its warmed up, and I put the truck in either reverse or a drive gear, it makes this noise like vrvrvrvrvrvr in the exhaust but only at idle, put your foot on the gas and it goes away. And its only when you put it in gear never in nuetral or park. Sounds a lot like a 4 cylinder engines exhaust. I was thinking EGR valve? I know I have a vacuum leak/open somewhere, maybe that has something to do with it?

 

Have you checked for exhaust leaks? The EGR shouldn't make any noise, but as far as my truck acted back when it was an automatic, the idle changes speed just slightly depending on whether it was in gear, or warm or cold, and noises come and go depending on engine speed, so an exhaust leak would be more prounounced at a very specific engine speed.

 

I did think about that, but I just havnt crawled underneath yet to find any. Its probably in the catalytic converter as I replaced the muffler and the tailpipe just last year.

 

Does it sound like it could be an exhaust leak, or does it sound more like a rattle (cause I removed my cat when it broke apart and started rattling at idle)

 

No, definitely just in the exhaust. Sounds a lot like an exhaust leak. I just hope its not too pricey to fix. My neighbor and I slaved over pulling off the cat and gutting it and putting it back together one weekend during one of the hottest days of the summer. I dont want to do that again.

 

Haha, I don't blame you there. If you know someone with a welder, fixing an exhaust leak is very easy. I fixed a leak on a friends chevy pickup with my mig welder and it took less than 10 minutes.

The absolute quickest way to find an exhuast leak is either in the morning, when its vaporizing all the condensation, or run some seafoam in it and watch where the smoke comes out! (I found a leak doing that but I have yet to fix it)