Engine Rumble When Coming Off Throttle

[91gmblack]

Hi All,

It started a week ago:
Doing 55-70 on highway, as I step off the gas pedal and coast, the engine starts making this droning roar like I was next to a Kenworth.

I checked the PCV valve and it was on tight.
I don't see any vacuum lines disconnected.
EGR valve is connected.
It's still running smooth, just noisy

And it only happens when i step off the gas.
Please help.

Thanks,
91gmblack

[gadget73]

Sounds like U joints going bad if I had to guess. Do you hear a loud 'clank' if you shift from reverse to drive with your foot on the brake?

[mrltd]

Crossover tube, air pump check valve?

[91gmblack]

Sounds like U joints going bad if I had to guess. Do you hear a loud 'clank' if you shift from reverse to drive with your foot on the brake?

No, no other noises.

[marquisman]

any sorta exaust leaks?

[91gmblack]

any sorta exaust leaks?

I'll check this Saturay when I'm changing oil.

Thanks guys.

[86VickyLX]

Hmm weird. Just noisy? Does it just do it while in drive? Or will it make that noise in park neutral etc? If it's only in drive, I don't thinkl it's the engine. I would look at the tranny.