• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Huge problems :( Engine maybe

Has anyone replaced just one piston in an engine before?

How hard is it, and what does it do to the rest of the engine with 120k on it, and one rebuilt cylinder?
 
Not the best practice IMO to do just the one, better this far into it pull the engine and do full rebuild, but that is me; but if in a bind a 1 piston repair can be done, how does the cyl bore look, any scoring ???, also since you are down, mite as well pull the pan and check webbing for mains before buying just 1 piston, you'll be pulling pan anyway to do the piston pull.
 
I did drive it a considerable amount without it firing. Mayexplain the carbon. She ran like a champ for years prior.

If it wasnt firing there wouldnt be the carbon build up, from the looks Id say for a year or more that cyl had low compression but it had enough to burn but not make a full combustion.

Has anyone replaced just one piston in an engine before?

How hard is it, and what does it do to the rest of the engine with 120k on it, and one rebuilt cylinder?

To pull the piston all you do is unbolt the connecting rod from the crank and push it up and out.

If I were you I would just try to find a used piston and get it going. It sounds like you really need the truck in the snow and winter is just starting.

The best thing I think is find a used or junk engine and build a new 6.5 and drop it in some time in the spring or summer.

I payed $650 for my truck to build a solid axle 4x4, you may be able to find a cheap truck like mine that runs good and swipe the engine.
 
Not the best practice IMO to do just the one, better this far into it pull the engine and do full rebuild, but that is me; but if in a bind a 1 piston repair can be done, how does the cyl bore look, any scoring ???, also since you are down, mite as well pull the pan and check webbing for mains before buying just 1 piston, you'll be pulling pan anyway to do the piston pull.

cyl bore looks perfect. no scoring.

you mean check webbing for main bearings?

I was going to try to replace the bearing also on that piston.

Time is not on my side at all with this. Needs to be emergency repair. I hope I can get all what I need tomorrow, but I seriously doubt it.
 
Matt what are you seeing in the "bad piston" I've seen far worse than what you have shown there, if in a bind, cyl isn't scored, I'd be inclined to run it, any of you other experienced 6.5 builders think similar, unless it's worse than what pics are showing me.
 
Matt what are you seeing in the "bad piston" I've seen far worse than what you have shown there, if in a bind, cyl isn't scored, I'd be inclined to run it, any of you other experienced 6.5 builders think similar, unless it's worse than what pics are showing me.

If it was mine I would probably leave that piston in too, just clean it and make sure it isnt crack or badly damaged. If its just some dings Id leave it myself.

If you plan on doing this fix and leave the engine go as long as you can I would probably put a new piston in.
 
cyl bore looks perfect. no scoring.

you mean check webbing for main bearings?

I was going to try to replace the bearing also on that piston.

Time is not on my side at all with this. Needs to be emergency repair. I hope I can get all what I need tomorrow, but I seriously doubt it.

Keep us posted. If doing the one cylinder will put you back in business, then do it!! May consider refreshing that motor in the off season, or getting another to refresh and put in when the snow melts. That way you will have all the bugs worked out by the next season.

Merry Christmas.
 
Matt, I agree with TD. I wouldn't put a new piston AND rings in just 1 cylinder. You'll likely find that that one cylinder would have a higher compression than the rest and it could cause some issues.

If the piston isn't cracked nor burned up, which it doesn't look like either, I would just fix the head and slap it all back together.

If you are going to replace one piston and rings, you'll want to do them all, along with honing each cylinder and replacing rod bearings and crank bearings.

If you are going to replace the one piston, hunt around for a used piston with the rings still on it, wash it out good in some diesel, then use that. In your off season you wan worry about overhauling the motor.

Just my opinion, though.
 
This was what I was thinking myself to be honest. What is the actual clearance in between piston and head to make compression? Are we talking 1/8" inch or less?
 
I'd clean the piston real good while i had it out, made darned sure it isn't cracked or gouged really deep or through and re-run it. Get the head work done, and put the thing back together. I've built a lot of engines through the years, it should stay together for a while. Also when it warms up, i'd be looking for another engine to either rebuild or replace that one.
Don
 
I'd clean the piston real good while i had it out, made darned sure it isn't cracked or gouged really deep or through and re-run it. Get the head work done, and put the thing back together. I've built a lot of engines through the years, it should stay together for a while. Also when it warms up, i'd be looking for another engine to either rebuild or replace that one.
Don

You think the overall quality of my engine is now in question?
 
Search the 'old site' for some old posts from Quantum Mechanic. He has done a single piston repair before....
 
Good luck....I haven't seen QM log on there in quite some time....

In fact, I don't log on there much anymore either....its turned pretty ugly...

Anyways - single piston R+R can (and has) been done successfully but as others mentioned already - while you are in there, you might as well freshen it up a touch....

ON EDIT - after looking at your pics again, I agree with Tim - unless there is a crack in the piston that is not showing up in the pics I would leave it alone. Get the head fixed, install new nylon rocker keepers and bolt it back together....
 
Matt what are you seeing in the "bad piston" I've seen far worse than what you have shown there, if in a bind, cyl isn't scored, I'd be inclined to run it, any of you other experienced 6.5 builders think similar, unless it's worse than what pics are showing me.

This is exactly what I was thinking earlier, I didn't want to say anything and start a shitstorm:rolleyes5: From the pictures it looks like it could just be cleaned up and put back together to hold him over until he gets the time to take care of it the proper way.
 
You think the overall quality of my engine is now in question?

No... but if you put it back together with that piston, we both know it isn't the best it can be. I would dream about that piston...

It will likely work fine for now, but if it was me, I'd feel a lot better with it rebuilt the way I know it should be. You're after an immediate fix, not a permanent repair, right?
 
No... but if you put it back together with that piston, we both know it isn't the best it can be. I would dream about that piston...

It will likely work fine for now, but if it was me, I'd feel a lot better with it rebuilt the way I know it should be. You're after an immediate fix, not a permanent repair, right?

I'd of course rather have both :)... Havn't seen the lower end yet, but really no reason to assume any damage under the pan, and its a hell of alot easier not to have to drop that at all.

Not to mention trying to find a piston and rings tomorrow so the mech can go nuts all weekend on it.

I can get the head fixed/machined at a shop done for Sat morning which means, truck may be up for monday.

I am also concerned about one cylinder in there with top compression while the others are fatigued. Leaving that piston would maintain it's natural compression relation.

I have checked out the old quantum posts. They helped. I also seen pistons that were really poor shape compared to mine.

It has a few beats on it, but still looks 'tough'.
 
I've seen pistons that looked worse been put back to use. My uncle has been running 6.2 and 6.5's for years and he has done all types of backyard fixes that have lasted. I guess lasted as long as he had the trucks LOL.

I feel for ya man. Times can be tough this time of year and breakdowns are never saved up for. Good luck with everything.
 
That piston would need to be 'cleaned up' to be re-used, that means the face extrememly smooth, at least not dimpled upward any amount, correct?

If it even sticks upward 1/32 of an inch, it would hit?

Meaning that piston would still need to come out to clean properly?

Still requiring Oil Pan Drop? (which grants full inspection to lower end)

It seems no damage where the valves clear, thats a good thing.
 
Back
Top