LB7: Broke something!

[REDHOSS02]

im trying to post the video but, Driving down the road and RPM's jumped and truck started shaking, I looked at the oil pressure almost 0. Too close for comfort I pulled over. I could smell burning oil but couldnt see anything dripping or wet other than a little from the valve cover which was leeking before. No white smoke from the exhaust. Engine is clicking and shaking to me it sounds like a cracked piston but i dont know!

 

[LBZ]

Broken crank maybe? The fact you were not blowing oil everywhere would lead me to think it's not a piston.

 

[Philtopgun]

the file has ".mov" at the end and the upload saying it doesnt recognize it. how you change the ending? I can get it to play on media player, but cant get the vid to load up on here. any suggestions be appreciated.

 

[REDHOSS02]

i think we have to upload it to youtube then post the url! just my assumption. What could cause the broken crank seeing how i wasnt in full throttle?

 

[REDHOSS02]

How much for an LB7 engine from socal? nothing too extreme maybe de-lipped pistons only. Not planning on too much power seeing how this is my everyday driver. just out of curiosity!

 

[REDHOSS02]

You know now that i think about it. Broken crank sounds right to me seeing how the engine is shaking real bad like it's out of balance, idles rough, and when you give it throttle it has a lag before it gets moving and sounds horrible. LBZ is on to something here!

 

[Akdiesel]

If you Pm/call Guy from SoCal he can give you pricing and will take his time to make sure the parts/work that is done will meet your goal and yeah I'd have to agree sounds like a broken crank

 

[REDHOSS02]

does anyone have a crank laying around?

 

[SmokeShow]

don't keep revving it trying to diagnose it... any smoke from the oil fill tube if you take the cap off?

 

[68skylark455]

does anyone have a crank laying around?

I have an 04 LB7 crank with 122,000 miles on it. PM me for a price if you need it.

 

[sddmax]

Zero oil pressure but there is oil in it? Hmmm It didnt all dump out on the road and you just didnt see it? When mine had symptoms like yours i cracked the #8 piston and the rear main blew out and the oil was gone in a second. I guess i could still see some dripping down tho. Just thinking out loud.

 

[skintback]

Sounds like the cam pin broke and it's out of time it also runs the oil pump

 

[REDHOSS02]

well when i looked down at the guage after i felt the surge it was at zero then climbed back up to bout 18 i guess. but when i would give it throttle the pressure wouldnt go over 40. Yes smoke comes out of the fill cap when i take it off, not alot but some.

 

[REDHOSS02]

I have an 04 LB7 with 122,000 miles on it. PM me for a price if you need it.

I sent you a PM thinking you had the complete engine! I believe my only option here is find a used LB7 and swap them out. Tare mine apart and sale the good parts.

 

[duramaxdiesel]

Oh man you brought back memories with that description. My first Dmax broke it's crank and sounded like that.

When my second Dmax blew two holes in the block there was no warning at all.

Nick

 

[dmaxfireman]

i have an lbz motor sitting here looking for a good home if you want to tear it down for parts. will also consider pulling the heads if you just want the short block for obvious reasons.

 

[JD4440]

Is the balancer rotating out of round ?

http://www.duramaxdiesels.com/forum/showthread.php?t=24614 LLY

 

[REDHOSS02]

I popped the hood and it seems to have a little wobble to it but. nothing too extreme, like a bicycle rim that has a couple loose spokes!

 

[REDHOSS02]

I would like to find a complete engine for a swap!

 

[Jared Duramax]

sounds like you just need a crankshaft. pull the belt off and try wiggling the balancer if it moves i would say just pull the motor and put a new crankshaft in it. chances are it didnt hurt anything, but you may have spun a bearing at the same time. its hard to tell at this point