Convicted1

Hey all..

I've been trying to track down the cause of this weird popping sound coming from my engine compartment for awhile. Like A LONG WHILE!!

I took some video of it but it didn't come out very well.. Seems to have been washed out by the sound of the exhaust.

But I found a video on youtube that is almost the exact same sound at the exact same circumstance.

Here is His Vid....



This only happens under heavy load in overdrive..

Please let me know what you guys think this is.

Thanx!

Convicted1

There is the video from my truck. I just played it back on my crappy laptop speakers and you can hear the popping just fine.

Starts at about 2200 RPM and 90MPH.

Helps if you play it in high quality mode as well.

Thanx!

BigIron70

90mph probally the governor kicking in.

trx

doesn't low rail pressure cause a popping sound?

Convicted1

It's not a low rail pressure issue. I do know that. Rail Pressure is at a Steady 24-25K

Thanks for the input though.

cbrahs

I know this may sound dumb but have you checked any of your wiper cowl or vent visor, bug guard? On a few of the GM rigs, if you have items such as that, they create funny noises at certain speeds. I used to work for Gm and more often than not, it was something the customer added, we removed and they were happy again. I have no idea if you even have anything like this on your truck but just kickin out an idea.

CHris

Convicted1

Yeah.. I know it not to be those things.

This happens on the Dyno as well. I have noticed that it gets worse when I turn the Water Methanol on. 25/75 mix of Meth to water. It's Washer Fluid.

-David

McnDiesel

The truck in the first video just had the head pulled it was a blown gasket in the very back between the two studs.It would only happen at high boost 70+ other than that it would run fine.It sounded like you were beating on the firewall by your acc pedal when it happened.

Convicted1

Yep...

Come to find out mine is the same issue.

Finally started leakin' oil so I could find it though.

Doesn't mix antifreeze and oil... Just spews oil out the back of the head under boost.

Freakin' weird! Guess I'll have to O-Ring it this time.