Diesel Place banner
1 - 6 of 6 Posts

·
Ronald Reagan fan
Joined
·
5,097 Posts
At nearly 400,000 miles, is it possible that a 6.5 could reuse the original pistons and only hone the cylinder walls before Installing new rings? 400k is nothing for a heavy duty diesel like in a semi truck, and they can usually be overhauled "in frame" without being bored out and having to have oversized pistons and rings - but would o be lucky enough to get away with that on a 6.5? Id like to put in new rings, gaskets, bearings, oil pump, etc... But without the expense and time associated with new pistons and having the cylinders bored out. Something is up with my 6.5 and it won't make a full revolution anymore even with the glow plugs out and the torque converter unbolted - if you spin it all the way around either direction, it stops in the same spot every time. This is while turning the engine over with a 24" breaker bar using the crank pulley bolt. It has 3 or 4 tight spots on the way around, but this one spot it just won't rotate through - ive pushed and pulled so hard that I though I was going to snap the breaker bar or the enormous crank pulley bolt. Anyway, its probably going to have to be taken apart but I sure don't want, nor do i have, thousands of dollars to spend completely rebuilding this thing. I love the truck and I've had it for about 15 years now so I really hate to get rid of it. But, its got a decent amount of blow-by now and since it's going to need work internally now, now is gonna be the best time to do an overhaul if i can in fact get away with that. If not, I may have to get something else unfortunately. Anytime the word "diesel" is involved, even if it isnt an especially popular like the 6.5, the price of a replacement engine goes up. A lot. Looks like about $4,000 USD for a reman 6.5 and that's just ridiculous.

Anyway sorry for the rant - but what do you all think about a re-ring "overhaul" of a high mileage 6.5. Is it possible that it would work and be worth the cost and effort?

Sent from my Pixel 2 using Tapatalk
Did you remove the valve covers afterward to find out whether a valve was stuck open?

You could do a rering with the engine still in place to get yourself out of a jam if that’s what you want to do.More than likely it has a cylinder ridge at the top on each bore so using std rings on a bore with a ridge present at the top automatically will tell you the bore is tapered but I have seen engines rebuilt using std rings with a ridge present and it turned out okay but it’s not the proper way to do it in all honesty.

The moment I see a cylinder ridge at the top of a cylinder it automatically means it needs to be bored oversize 9 times out of 10.
 

·
Ronald Reagan fan
Joined
·
5,097 Posts
Yep. The only ones that are open are the ones that the cam lobes are on - and they close when i rotate the engine they all seem to work ok. Next step i suppose is to pull the heads. There's nothing else in the way of that now on the passengers side - intake, IP, coolant crossover, exhaust, valve covers etc. And only the ps pump and exhaust manifold on the driver's side.

One thing that may or may not be important to know is that the passengers side exhaust manifold has been off most of this time and the air intake from the turbo has been uncovered. I didn't stuff rags into the exhaust ports or the upper intake, but I have kept the hood closed - it hasn't been rained on or anything like that.

Sent from my Pixel 2 using Tapatalk
It’s Pretty strange this sort of thing has happened.It was okay when you last parked the vehicle and now it can’t be rotated a full rotation.Awfully strange circumstances to say at the very least.
 

·
Ronald Reagan fan
Joined
·
5,097 Posts
I know. There's got to be an explanation for it though, only disassembly is going to reveal it tho it seems.

Sent from my Pixel 2 using Tapatalk
Hopefully you’ll find something when the heads are taken off.
 

·
Ronald Reagan fan
Joined
·
5,097 Posts
Yeah hopefully. If not, it'll be time to pull the entire thing out. It irritates me to know that I put all that effort into reinstalling the transmission only to have to undo everything again because of a serious, unusual and certainly unexpected problem. It's not any fun handling that 4l80e. I can't believe how heavy it is.

Sent from my Pixel 2 using Tapatalk
Yes those 4L80 units are heavy buggers indeed.I can pick up a 700R4 no problem and carry it around but the 80 is a heavy sucker.
 

·
Ronald Reagan fan
Joined
·
5,097 Posts
No, but not having any ridges or scratches in the cylinder walls is certainly a good thing. Its better than any gasoline engine that ive ever had apart.

Sent from my Pixel 2 using Tapatalk
Try using a ball/flex hone to do the honing pattern.Some guys use the three legged hone which is okay too.The ball hone does a pretty good job overall.I bought a couple different grits from eBay.
 

·
Ronald Reagan fan
Joined
·
5,097 Posts
I believe you've got the cylinder taper backwards? Isn't the wear on a high mileage engine at the top of the bore more compared to the bottom.
Your right.Cylinder wear occurs at the top section of the cylinder and eventually most cylinders will taper as the miles accumulate
 
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top