E6 350 problems

[bobcotkg]

Hi All,

I have an E6 3504 valve in my Superliner. It has been a very reliable engine, until recently. It has had the gray smoke coming out the pipes for a while now, and knew it was about time. In January I was coming down over a hill when it started knocking. Then the knocking quit and I drove it until I could get off road. Ended up going home tearing it apart to find a melted looking piston and bent valve on #5. I just stuck one piston in it, a set of injectors and one reman PAI head. The injection lines were seaping from the head, where they meet the injectors. I ordered new lines to put on. In this time it started having quite a bit of crankcase pressure and smoked out of the breather, smelled just like diesel. I also noticed the oil became thin and smelled like fuel. I was putting out of the woods and it started knocking on me again last week. I feared the worst, but the noise quit and I drove it home. It didn't run right. We thought it was a fuel knock that went away. I put the new lines on and changed the oil. Nothing was better. #4 dead. Took head off only to find #4 piston damaged severly. #6 looks funny like it will be next.

I am planning on doing a complete inframe this time. But question is; What is going on with the melted looking pistons ect? I've had this truck for 7 years or so, and put many miles on it and never even a glimmer of a problem with the engine, or really anything. I have done nothing to "hop it up" because I didn't want problems and heard 350s didn't hold up it you messed with them. I don't know how many miles are on engine. It shows 600k on odometer. Engine has tag where it was remacked in '90.

I don't want it to mess up again in a couple months. Any ideas?

Bob

[Rob]

Hi All,

I have an E6 3504 valve in my Superliner. It has been a very reliable engine, until recently. It has had the gray smoke coming out the pipes for a while now, and knew it was about time. In January I was coming down over a hill when it started knocking. Then the knocking quit and I drove it until I could get off road. Ended up going home tearing it apart to find a melted looking piston and bent valve on #5. I just stuck one piston in it, a set of injectors and one reman PAI head. The injection lines were seaping from the head, where they meet the injectors. I ordered new lines to put on. In this time it started having quite a bit of crankcase pressure and smoked out of the breather, smelled just like diesel. I also noticed the oil became thin and smelled like fuel. I was putting out of the woods and it started knocking on me again last week. I feared the worst, but the noise quit and I drove it home. It didn't run right. We thought it was a fuel knock that went away. I put the new lines on and changed the oil. Nothing was better. #4 dead. Took head off only to find #4 piston damaged severly. #6 looks funny like it will be next.

I am planning on doing a complete inframe this time. But question is; What is going on with the melted looking pistons ect? I've had this truck for 7 years or so, and put many miles on it and never even a glimmer of a problem with the engine, or really anything. I have done nothing to "hop it up" because I didn't want problems and heard 350s didn't hold up it you messed with them. I don't know how many miles are on engine. It shows 600k on odometer. Engine has tag where it was remacked in '90.

I don't want it to mess up again in a couple months. Any ideas?

Bob

You may have had bad injector tips for quite some time. Sounds like a couple of cylinders were overfueling and melted the pistons. Sometimes you can feel this, sometimes you can't. I like to pull injections periodically and send them in for recalibration as they really are a neglected wear item.

Rob

[bobcotkg]

I sure hope thats all. I hope with everything new things will be back to normal. I ordered a complete inframe kit with the Dynatard rebuilt kit too from PAI. It was $1400 all together. Thought that was fair enough

Bob

[theakerstwo]

Then check the timing and make sure its got good boost. Should have at max about 22 to 26 psi. If not start to check things like bad turbo and leaks on the air/air cooler and piping.Also to hope you have not by mistake run gasoline thru it? glenn

[bobcotkg]

Laughing, No I haven't ran it on gasoline, although, I have heard of people that have tried with catastrofic failure! But it is a question that had to be asked

Another friend brought up timing. I haven't done anything to it, but doesn't mean something isn't worn enough to let it be out enough. I will definately check the boost, something I hadn't really thought of. I don't let pyro go over 1000, but I suppose it could be hotter in the cylinders than after turbo.