Help identify sound

D

Damian

Member
Re: Help identify sound

I pulled the belt off and listened again. I can't hear anything really coming from the intake manifold or turbo. To me it's really coming from the front of the motor. I thought the water pump, but it's not that old and it still makes the noise with the belt off. I use a ratchet extension as my stethoscope and I still can't find where the noise is coming from. I felt the timing cover and didn't feel anything unusual.

This time the idle dropped to 500 which is unusual.

I really just need to fix this thing again and just leave it parked!
 
DaveP

DaveP

Active member
Re: Help identify sound

The noise sounds very different in the second video. It was making me wince, because it sounds mechanical. It's not the 'pop' it was in the first video.

If you have a magnetic drain plug, pop it out and take a look at what's on it. You don't have to drain the oil, just take a look at the plug while you put your finger over the hole to keep the oil in while you look.
 
midnightbluS10

midnightbluS10

Banned
Re: Help identify sound

I won't be surprised if Dave is dead on with his diagnosis.

It also seems to be very random, though. And sometimes there's multiple pops one after the other. I'm sure there could be more than one cyl involved.
 
Don W.

Don W.

Stab it and steer it
Re: Help identify sound

X2, in the second vid it sounds more like old fashioned rod knock which can be somewhat random. (Throttle, RPM, and load on the motor can have an effect on the sound.) Like the second vid but not like the first which kinda confuses things. Cut the filter and look for bearing material.
 
D

Damian

Member
Re: Help identify sound

I hope it's not bearings again, I just replaced the bearings about 3 months ago. If it is, I might just sell the truck.

Everything was fine with this thing, then I changed the oil. A couple days later I would hear a pop here and there. I'm using Lucas 10w30 right now and oil level is good.

Oil pressure has been good too, never goes below the 25psi line on the gauge at idle.
 
D

Damian

Member
Re: Help identify sound

Gonna pick up a magnetic drain plug here in a bit, put it in, run the truck for a bit, check the plug and cut the filter.

Why can't this thing just run peacefully?
 
Don W.

Don W.

Stab it and steer it
Re: Help identify sound

Magnetic plug ain't gonna help much. Bearing material is not magnetic.
 
DaveP

DaveP

Active member
Re: Help identify sound

Don W. said:
Magnetic plug ain't gonna help much. Bearing material is not magnetic.
Click to expand...

Pic is worth a 1000 words: (It's hanging from the magnet. It looks like it's on a table, it's not. I used my kitchen cabinet as a background).

IMG_2363.jpg

IMG_2364.jpg


The crank shaft, connecting rods, oil pans and cylinder cases are too. You're right the Babbitt material is non-ferrous, but it's not very thick. Once you can hear a bearing problem, its most likely "making metal" because it's gone to the backing.

My thought process is hard to follow through a monitor. My thought on the magnetic plug is this: There shouldn't be jack-shit on the plug (other than perhaps some grey "mudd" from the cyl walls from break-in). If there is, it's bad news, and the engine has to come apart again..... That second video sounds like bearing knock that IMO is severe enough that the damage has gotten into the steel backing on the bearing, and will show up on a magnetic drain plug.

There are some aluminum-backed bearings, but they are not widely used, and are now very difficult to source. I used AP series bearings for decades, but now use steel-backed like everyone else because that's all that's readily available.
 
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Don W.

Don W.

Stab it and steer it
Re: Help identify sound

I'm with you 100% Dave, I just think that if the motor has gotten to the point where it's making ferrous metal the noise wound be much worse than it is. That's all. I guess we'll just have to wait and see what happens.
 
DaveP

DaveP

Active member
Re: Help identify sound

Don W. said:
I just think that if the motor has gotten to the point where it's making ferrous metal the noise wound be much worse than it is.
Click to expand...

lmao @ Damian's expense. In that second vid it sounds pretty damn bad to me. I think it has to come apart again. I'm glad its not mine. I've got enough chit to get dunn around here.....
 
D

Damian

Member
Re: Help identify sound

I'm really considering doing an LS1 swap instead of touching this motor again. This will be the 3rd time he motor will be pulled in less than a year.
 
SY2455

SY2455

70's Veteran
Re: Help identify sound

Who is doing your engine work? If you are not doing it then you need to find someone else.
 
D

Damian

Member
Re: Help identify sound

I did it the last time, 3 months ago, and a reputable shop did it the first time. Ive never had so many problems with an engine until I got this thing.
 
D

Damian

Member
Re: Help identify sound

Would too much oil cause this noise? I checked the oil level and it's above the full line, I wasn't paying attention to which bottle I was on and put a full 5qts in. I'm gonna start pulling shit apart here soon.
 
Don W.

Don W.

Stab it and steer it
Re: Help identify sound

Damian said:
Would too much oil cause this noise? I checked the oil level and it's above the full line, I wasn't paying attention to which bottle I was on and put a full 5qts in. I'm gonna start pulling shit apart here soon.
Click to expand...

Nope, not really. Unless you went way over full. Even then I think it would just push it out. But too little oil, yup.

Bunch of interesting comments. Question: Did this just happen out of nowhere? IOW what's the history? Any other details?
 
D

Damian

Member
Re: Help identify sound

Just happened out of no where. The only thing that changed was the oil change, but I've ton tons of those over the years. I was going to work on the truck but decided alcohol was what I needed tonight, will work on it tomorrow.
 
wildphil

wildphil

I Love My Ty's
Re: Help identify sound

What brand bearings were used on your rebuild? Are you still with a stock tune? I'm curious. There has been a lot of our trucks with v6 engines that have had bearing failure lately. I lost mine in a 2k mile engine. It would be nice if we could find out why. And hopefully stop the issue. I really hope for you it is a less serious problem causing the noise.

Keep us posted.
 
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