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My rapping motors

96TD

Recruit
Messages
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Location
Wilmington, MA
I have been posting in GMC 6.5TDs post on his noisy motor, but don't want to hijack it, so I'm starting my own post.
My main motor is rapping after a long trip up a steep hill where it got a little warm. Hit about 230 real quick before it defueled. When the trailer got a flat and I pulled over to changed it, I heard the horrible rap.
I'll post a video in a following post.
I just ordered a set of injectors from Heath Diesel and talked with Bill for a little while. He said that if it was overheated the a piston can be damaged and how to check for it. He said to remove the oil cap and if the oil chimney chugged like an old choo choo, then I had a damaged piston. Well, I tried it and I have a locomotive under the hood. :sad:
Motor 2 is a parts truck that I just picked up, with similar symptons and noise. It didn't chug like my DD, it was a little more of a flow than puff puff. Anyway, when the new injectors get here, they'll go in the parts motor, so that I can see if that motor is good enough to put in my DD. Then for the heck of it, I'll try it in my DD.
 
Ya know, I did the test that Bill Heath told me to do, and the results point to a damaged piston/cylinder. The thing is, I had that chugging before the motor started making noise, just not as bad. I'm thinking that the motor may have been on it's way out, and I just pushed it over the edge. I'm also thinking that this may actually be the reason that the previous owner dumped it. Well, that and the vacuum pump was gone, so it had no boost.
Still waiting on the injectors. Once they come in, I'll thrash with both motors to diagnose them. Even if the motor in the parts truck is good, I may just buy new. I need the truck reliable. If I break down several states away, towing my enclosed, it isn't going to be cheap to get them home. Anything that is saved from going the cheap route is going to be lost towing everything home. Not to mention, I will then have a cool new motor. We'll see. I'm hoping the injectors will get here Thursday, then I can start working on one.
 
OK, it has been a while, but I have been too busy to touch anything.
I never tried the injectors in either. Both had the noise even when I cracked injector lines.
I know the engine in my dually is bad. It's rapping pretty bad, and it is puffing smoke out the oil fill tube pretty darn good.
The other motor, had a rap also, but didn't chug like mine, and the rap sounded different. The guy that I got the truck from said he thought it wasn't a bearing. That is why I got it. I was hoping it was a bad injector. That doesn't seem to be the case, so I tore down what was left of the truck, started pulling parts off the motor, and eventually pulled the motor.
This is what I found, and think may have been the noise, but need other people's opinions before I think about using it in my truck.
When I was pulling the IP, I only found two bolts holding it in and both bolt heads were banged up. I thought the IP had 3 bolts. When I got it out I found out that indeed it had 3 bolts at one time. The third had broken, and the head is probably what banged up the other bolt heads.
Now, for my question: Could this be the noise that I was hearing?
My thinking is that with the drive gear having angled teeth, it was pushing the gear out where the broken bolt was, and the noise was it popping back in. Does this sound possible? The truck was pretty much torn apart, so I couldn't exactly put it back together to try out my theory.
 
Huffing out the oil filler is almost surely a piston with a hole in it.

Gonna have to get it out and apart.

Not an item to try and fix in the chassis.


Missy
 
Thanks for the reply, Missy. That one is definately coming out.
The one I have the question about is the other motor.
It wasn't huffing oil, but had a broken bolt on the IP gear. Could that cause a rapping noise. It didn't sound as bad as my other motor, and cracking inector lines didn't change the sound at all.
 
it would cause more of a whining noise I would think, unless the gear was loose enough to slap against things.
 
I recently pulled the engine from my 93 in my sig. It had a loose ip gear. The PO had just had the ip rebuilt less than 500 miles previous. The heads of the bolts will catch on the lip from the oil filler. It makes some terrible noises. None of mine had fallen out yet. Only damage was the bolt heads skun up some. The real bad noise was coming from the broken flexplate.
 
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