Filled up this morning at the usual station-Drove 60 miles to the wifes parents- parked it for an hour or so-cranked up and drove down to the country store and got out while running....I heard a noise that sounded like an air compressor running in the background of the regular engine noise. Engine was running great so I figured I'll drive it back to the in-laws. I got back and the noise was still there and then comes the ses light on the dash.

I disconnected the edge and called a flatbed. I thought possibly water was in the fuel but if it was making the engine sound funny it had made it past the oem filter and there was nothing I could do.-:t

To me it sounds like a dadgum rod knocking around??? This GMC has 75,000 on the clock and is driven 99% hwy and never flogged...hard.

If this is a major issue (like connecting rods etc) I will loose all faith in the durability of a duramax cause injectors are enough to think about.

Anybody wanna guess what's wrong with my baby?

Any codes and what are they?

Can't read codes and the dealer was closed.

Did you hear what side it was coming from and do you have a vacuum pump on that engine?

At first is sounded like it was coming from the fuel filter side but changed and sounded like the whole engine. No pump to my knowledge.. I woke up this morning and remembered something that happened before the problem.

Driving yesterday, I felt a little kick in her step for a second. It was almost like she was shot in the side with a .22. I was going about 25-35 & softly accelerating. I thought mabey I ran over a stick or something. It felt like a stick popped up and hit my fender liner. WTF?

Does your truck have EGR? if it does you have a vacuum pump. Its on the lower right front of the engine, its belt driven. It kinda sounds like its coming apart to me.

It was the Vacuum Pump.

Bingo

Way to call it clyde..

Is it common for these trucks to lose vacuum pumps? I really don't need another thing to think about especially with only 70K on his truck.

Its not "common" but it does happen. I've replaced a few.