At 440,000 mine finally blew a head gasket. We tore it down to the short block, still in the truck, and simply replaced everything from the heads up (except the injection pump), including the turbo, timing change, damper, rocker arms, etc. I also replaced every rubber hose under the hood I could find, being careful to use the correct hoses for things like the turbo oil return. It runs great, no issues at all. Once thing I didn't do that I wish I had, when the heads are off, replace the lifters. Removing the heads in the only way to get them out so take advantage of that. I didn't know that until after the heads were back on.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?
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"At 440,000 mine finally blew a head gasket." Only 440,000 miles and the piece of crap blew a head gasket? GM junk.At 440,000 mine finally blew a head gasket. We tore it down to the short block, still in the truck, and simply replaced everything from the heads up (except the injection pump), including the turbo, timing change, damper, rocker arms, etc. I also replaced every rubber hose under the hood I could find, being careful to use the correct hoses for things like the turbo oil return. It runs great, no issues at all. Once thing I didn't do that I wish I had, when the heads are off, replace the lifters. Removing the heads in the only way to get them out so take advantage of that. I didn't know that until after the heads were back on.
Pull the heads and that will tell you if you have rust, hydro lok, cracked pistons.Already have the glow plugs out. Still have the same issue. I had wondered about that myself
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I must've cleaned that one up some before I took the picture there's no gasket crud in the water jackets or anything like that in that picture like there is on the other head...Looks like one side is running better than the other with one head valve surface being black from I would assume diesel sludge.
Upon looking at the pictures again, picture 4 is the passengers side head and picture 9 is the drivers side head, before any cleaning was done. I remember because the first head i pulled was the passenger side one and i stood it up on its end in front of the truck on a piece of tar paper that was laying there for some unknown reason. The drivers side head I laid down on it's side on a red block. The other pics of the heads are after i cleaned the bottom side so I could see things better.Looks like one side is running better than the other with one head valve surface being black from I would assume diesel sludge.
Is that piston melted or is it just me?Ok here's an update.![]()
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Ill look at it closer but I don't think so, it has a lot of carbon built up on it thoIs that piston melted or is it just me?
I think the rings are worn out, but I think the cylinder walls are OK. It had blowby, so something is certainly worn out. I think im going to hone the cylinders and put in new rings when it gets put back together tho. The cylinders look great to me.That motor is past wore out, just because you can see what looks like cross hatch, doesn't mean there is anything there for the rings to seat to...
Are you going to send the heads in to have them checked and at least surfaced.I think the rings are worn out, but I think the cylinder walls are OK. It had blowby, so something is certainly worn out. I think im going to hone the cylinders and put in new rings when it gets put back together tho. The cylinders look great to me.
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My eyes aren't good enough to gauge taper and roundness.😓The cylinders look great to me.
Yes. The machine shop I use is running a month behind on work right now though. I'm going to look and see if I can find another one that can get to it quicker because I really want this truck back asap.Are you going to send the heads in to have them checked and at least surfaced.
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.My eyes aren't good enough to gauge taper and roundness.![]()
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.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.
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