LB7 Urgent help..

[6cummins]

Need some help guys. Buddies 02 LB7. Has a built trans, dual fuelers (tune runs stock pressures max around 23k), AD165, HTT 66. Truck spun the harmonic then other day and we fixed it with EDPs pin kit. Took the truck for a spin yesterday. It was running perfect, right before we got home we hit it from a slow roll and the truck spun a ways. Came to a stop and now the truck is making a muffled exhaust leak sound. I couldn't narrow it down last night so going again tonight to look again. Idles perfect, oil pressure warmed up at idle is about 20 psi, the noise does increase with RPMs. Its overall not extremely loud. It isn't like a knocking noise. I stuck my had by the turbo gasket and up pipes and didn't feel any exhaust leak. Balance rates all looked good as well. No codes either. I did some reading and a guy described a sound similar and it was his copper washers on injectors. Could that be possible? Truck has 145k but injectors were done about 25k ago. Oil looks clean on the stick, no fuel from what I could see. Just looking for some ideas to get this narrowed down. Thanks

 

[chevyburnout1]

Could you post a video of the noise? Is it smoking any?

 

[6cummins]

Could you post a video of the noise? Is it smoking any?

I'll get a video tonight. Gonna cut off each cylinder tonight and see what happens.

 

[adeso]

get one of those cheap stethoscopes from a parts store. They do wonders for tracking down noises. Check for blowby and did it push any coolant?

 

[6cummins]

Here is a video and an update.. Just about 98% sure its coming from passenger side. I pulled the oil cap and it has no excessive blow by. Truck isn't smoking any and isn't using coolant either. Idles like it should and revs up fine with no missing or nothing abnormal, the noise does increase speed a little with RPMs raising but it doesn't get louder or worse, Its actually loudest at idle. Cold crank up it has about 40 psi of oil pressure. After warm up it has about 20 oil psi. Here is the odd thing. When I first cranked it up the motor was cold the noise wasn't there, or I couldn't hear it. After it warmed up and the oil psi dropped from 40 to 20 is when I started being able to hear it again. I drained the oil and no diesel in it. I did see about 2 or 3 very tiny silverish shavings though. I used EFI live to cut each injector off individually and it still made the noise so I believe its mechanically. Possibly valve train? Lifter? Bearing? Need some help guys.. Doesn't really sound like a hard rod knock in person.. Truck was running perfect til one hard run then it started doing this.

http://youtu.be/b71L15GtjIs

http://youtu.be/1NFcLiYgID8

 

[6cummins]

Only thing left I can think to do is a compression test and pull the valve covers and seeing if anything out of ordinary stands out?

 

[adeso]

I would get that stethoscope and see where it is coming from. I cant tell from the video

 

[dirty_max]

it is hard to tell from the video, but it kind of sounds like its popping through the intake or exhaust

 

[6cummins]

Here's a cold crank up video. Noise doesn't really exist
https://www.youtube.com/watch?v=6KZshurSNRo&feature=youtube_gdata_player

 

[6cummins]

it is hard to tell from the video, but it kind of sounds like its popping through the intake or exhaust

I was wondering the same thing. In person it sounds more like a echoing in the motor vs a rod knock or anything. But I could be wrong.

 

[6cummins]

Anyone? Need some help

 

[blk smoke lb7]

The video isn't very long it's very hard to tell your probably goes Nguyen to need to do a compression test if that comes out clean probably need to pull the passenger side cover and look for a bent push rod or anything out of the ordinary.

 

[6cummins]

The video isn't very long it's very hard to tell your probably goes Nguyen to need to do a compression test if that comes out clean probably need to pull the passenger side cover and look for a bent push rod or anything out of the ordinary.

Thanks! That was my next step. Can I just pull the 4 glow plugs on passenger side to test. Or do I need to remove all 8 still just to test the passenger side?

 

[hondarider552]

I normally pull all 8 out.

 

[6cummins]

I normally pull all 8 out.

Ok I'll do that. Thanks! If it was a spun bearing or something wouldn't oil pressure be extremely low if any?

 

[04D_MAX]

Ok I'll do that. Thanks! If it was a spun bearing or something wouldn't oil pressure be extremely low if any?

you only need to pull out the ones you are testing...

 

[dirty_max]

oil pressure would more than likely be erratic, low, inexistent, or all of the above if it spun a bearing.

 

[6cummins]

oil pressure would more than likely be erratic, low, inexistent, or all of the above if it spun a bearing.

And if it cracked a piston, major blow by would be happening and its not.. Im thinking its something in the valve train. Going to do a compression test tonight. Do you have to pull heads to access lifters on LB7?

 

[Chevy1925]

yup. Lifters are solid lifters though, not hydraulic

 

[6cummins]

Checked the compression on the passenger side bank since that is where I believe the noise is coming from. All 4 cylinders were at 400 psi. But when I pulled the glow plugs the #7 glow plug it had oil on it when the other 3 were dry. Cranking the motor over the #7 cylinder had a light MIST of oil spraying out the whole time. Nothing super heavy but a steady mist when cranking it over. Going to check the driver side also.