Hey guys Ive wanted to post and ask about this noise I hear when I first start the truck (after sitting over night). Once the truck is started and idles for a minute you hear the exhaust start to sound like a jet engine. If you tap the pedal it goes away?? Then it will come back again. Usually after I get the truck a little warm and start to drive the sound never comes back. But today it was around 25 here in Northern NJ and I started the truck had it on high idle and theres the noise. I then started to drive after warming it up slightly and the noise was still there while driving. Thats never happened to me before.

So after that long winded thread haha I'm just curious to what is that noise?

-AJ

 

The "jet engine" sound is almost always caused by a closed Exhaust Back-Pressuer Valve (EBPV). It's to help the engine warm up faster when it gets really cold. It should go away as soon as the engine begins to warm up.

Exhaust back pressure is controlled to provide more heat to the coolant when ambient air temperature is below 45°F and engine oil temperature is below 167°F during low load.

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