Golden Helmet
Full Access Member
It just started doing this recently, it was intermittent but now it's constantly humming / grumbling when the truck is in gear and sitting at idle. You can see in the video that the noise goes away in Park / Neutral, but when the truck gets in gear and the idle lowers something starts making noise.
So far I've tried removing the belts one by one to see if it was an accessory making that noise, but even with no belts on at all it still makes that noise. I added one quart of oil to the engine (it was a bit low, it drinks 1qt every 3k miles and I'm almost due for my 3k mile oil change) and that seemed to quiet the noise in Reverse but not Drive. Added another 1/2 quart and no change.
Also, weirdly enough, the noise seems to go away when I'm going through the deep potholes at work and the front end is flexing. Whenever the suspension passes its normal height the noise comes back, but while it's flexed or bouncing the noise goes away. I have absolutely no idea how my busted up D50 can have any say in the noise my engine makes, maybe I've been inhaling too much diesel exhaust lately
The only testable things I can think of that might be the cause (just going for low-hanging fruit, if it's engine internals then I'm screwed):
- Could one of my water pump bolts be over-torqued and grinding on the engine gears? I would think if that were the case then it'd be noisy at all RPM's, but I am often wrong.
- Maybe my idle speed is too low? I used to have it idle at a higher RPM, but it likes to "self-adjust" back down to what it is now. I haven't adjusted it in a while.
As always, I appreciate your guys help and input. I thought about raising my idle RPM just to shut it up, but I figured I'd better check with you guys first. Maybe one of you will recognize this as "the noise my engine made just before parts fell out", I hope not but I'd rather find out now than on the side of the road.
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So far I've tried removing the belts one by one to see if it was an accessory making that noise, but even with no belts on at all it still makes that noise. I added one quart of oil to the engine (it was a bit low, it drinks 1qt every 3k miles and I'm almost due for my 3k mile oil change) and that seemed to quiet the noise in Reverse but not Drive. Added another 1/2 quart and no change.
Also, weirdly enough, the noise seems to go away when I'm going through the deep potholes at work and the front end is flexing. Whenever the suspension passes its normal height the noise comes back, but while it's flexed or bouncing the noise goes away. I have absolutely no idea how my busted up D50 can have any say in the noise my engine makes, maybe I've been inhaling too much diesel exhaust lately
The only testable things I can think of that might be the cause (just going for low-hanging fruit, if it's engine internals then I'm screwed):
- Could one of my water pump bolts be over-torqued and grinding on the engine gears? I would think if that were the case then it'd be noisy at all RPM's, but I am often wrong.
- Maybe my idle speed is too low? I used to have it idle at a higher RPM, but it likes to "self-adjust" back down to what it is now. I haven't adjusted it in a while.
As always, I appreciate your guys help and input. I thought about raising my idle RPM just to shut it up, but I figured I'd better check with you guys first. Maybe one of you will recognize this as "the noise my engine made just before parts fell out", I hope not but I'd rather find out now than on the side of the road.
