CAT 3306 Problem in 97 L9000

[JDMGrading]

Hello all, I was recently hauling down the interstate running about 2000rpms at 68mph in my 1997 Ford L9000 Dump truck.

Then I noticed it started skipping and missing and blowing smoke out of the blowby tube and leaking oil between the oilpan and block. Also blue and grey smoke coming from stack under load with almost no black.

I thought it could have been an injector, so I cracked all the lines with it running and the only one that did'nt change any sound in the engine was the #1 injector. So I replaced the injector and thought it was fixed until I got about 15 mins away from the shop. And it only sputters from 1000rpm to about 1600 and then clears up and sometimes around 1850-2000rpm it would pop like a misfire almost.

So now i'm stumped and don't have any experience whatsoever with this 3306 and I do not know where to turn.

I've been told it could be a cracked piston or cracked ring causing the excessive crankcase pressure and the stuttering...does this sound right? engine has 305,000 miles.

Any help or information would be greatly appreciated because I can't really afford to drop it off at Carolina cat.

 

[dirty doyle]

Those things were known for loosing a piston and liner if you didnt let them warm up before putting a load on em. Could be a valve problem but if you are getting lots of blue smoke and blowby its internal

 

[GOINGBROKE]

Pull injector back out, roll engine over until valves are closed or remove valve covers and rocker arms - pressure cylinder with blow gun through injector hole and see if cylinder holds pressure. You will be able to tell if its a piston or valve by where the air is leaking or if cylinder holds pressure all should be goood.

 

[JDMGrading]

Well today I found out that I have cracked the #1 piston. But also the valves were hitting the #1 piston as well.

What does this mean? Mechanic says I need to have the head reworked but if I could get away with some new valvesprings that'd be great.

Any and all suggestions would be greatly appreciated!

 

[Will Musser]

Go ahead and get the head redone. It's cheap,and it's time at 300k.

 

[biggrader]

I'm with Will, better have the head reworked. Would hate to break a valve and have to put in a new piston again!