6.5 TD Crank

[6.5 Detroit Diesel]

Okay, here is the problem. 1997 6.5 TD passenger van. The crank is broken. The front end is wobbling like crazy, tons of crashing noise from inside the van, and the engine is burning tons of oil. (Blue cloud following it around). Hopefully it is just the crank. There is some 6.2 engines in the local wreckers. The question is, would a 6.2 crank fit the 6.5? Hopefully that is all it is, but the whole engine is going to have to be pulled. :mad:

[Robyn]

Stop running it and get it apart
Yes the 6.2 crank will work fine.
The chances that the block is still good after a broken crank with lots of crashing noises is in question though.
Good luck

Robyn

[john8662]

Correction to advice above. A 6.2L crank will not work in a 6.5TD, unless it is the later 6.2 crank.

Basically, single piece rear main seal crank will only work in single piece rear main block (could be 6.2 or 6.5).

Two piece rear main seal block (all 6.2's prior to 1992) will only fit 6.2 blocks.

J

[6.5 Detroit Diesel]

Well that sucks that the year has to be 92' or 93'. Taking the heads off tomorrow. I am trying to think why it would be blowing so much smoke all of a sudden. Engine is shaking and when I checked the oil, there was very little. Any major repairs are going to cost a ton.

[Robyn]

John. good point ;) 91 6.2's were also single piece rear main depending on early or late. My 91 Burb had single piece main seal (599 block)

Once the crank goes it can be some tough sledding though as the mainline can get tweeked real bad if not damaged beyond use.

Now is this a N/A 6.5 or a turbo??
If its an NA engine you can swap in a 6.2 and use your front timing cover to provide a location for the crank sensor.
The rest of the goodies will fit. You would need to use your IP.

This is a sticky wicket though as there can be some hinky little things that might jump up

If its a turbo engine your out of luck as the 6.2 has no rear mount location for a turbo and or oil feed and drain back fittings.

Ge the 6.5 out and apart and see what you have left to work with.
Then let us know and we can proceed from there.
Without seeing what you have Its tough to speculate.
A crank can be had fairly easily though through many sources for little $$$$

Let us know

Robyn

[gmctd]

It's really moot at this point, but the pistons are no longer traveling the cylinders in a linear fashion - they're being thrashed by the broke crank, so you get much less ring-seal - plus, you prolly got at least one cracked\broke slug - needs ta get it apart, rather than guessing - good post, btw - you'd be surprised at the number of people who believe the 6.5 engine won't continue to run with a broke crank................

BTW, John - my condolences on your recent loss - any further info - similar to this?

[john8662]

BTW, John - my condolences on your recent loss - any further info - similar to this?

Thanks.

I haven't had any time to myself lately to get to the removal of the engine. I'm hoping to get the chance to start the removal one day this coming weekend.

J

[6.5 Detroit Diesel]

Out of luck as it is a TD. Stupid van, little room to work on it. It's a center mounted turbo.

[Robyn]

Rip it apart and see what you have left to work with. :(

Robyn

[EWC]

Watch that too , as in the center mount turbo . The heads and block are different .

[6.5 Detroit Diesel]

Is the block different as well as the heads and manifolds? I had heard only the heads were different. Pulled off the oilpan today and took a quick look. Couldn't see anything weird. Tomorrow when I have more time I will pull off the bearing caps and check the journals. :mad:

[EWC]

Main issue with the blocks are the mounting and oil feed/drain back holes for the center mount turbo .

[6.5 Detroit Diesel]

Okay, so I have pulled off most of the caps on the crank and everything looks good. So I pulled off the turbo. Turbines spin freely and there is no contact with the walls. There is a little oil sitting at the front of the intake turbine. The van has been sitting for over a month and there is still oil build up. I am not sure if there is more oil than normal or not. Methinks not but I am not sure.

[gmctd]

Check the crank nose and front main area as you forcefully manipulate the harmonic balancer\acc pulley - be easier with the serp belt off

It's looking like a holed piston, maybe crunched valve(s), from all that smoke and noise - one dead cylinder in a Diesel has more catastrophic-appearing effect than in a gasser (patooie!) - you might be able to see a holed piston from below, with a good spotlite - if not clear, pull the valve-covers - if all rockers inplace and valvestems still well-sprung, pull the heads

The turbo is prolly ok - but for now, remember: don't sweat the petty stuff, pet the sweaty stuff!

[6.5 Detroit Diesel]

Thanks. I am starting to lean towards the holed piston idea. Can't see anything from underneath. Have removed drivers side head. Everything is clean on this side. You can still see the hone marks on the cylinder walls for crying out loud. A buddy came by with a camera yesterday, but we couldn't get the camera past the precup. Passenger side head is all that's left. Whoever made these freaking vans obviously didn't plan to work on them!

[6.5 Detroit Diesel]

Finally got around to pulling the second head. I have found a broken valve and the coresponding piston is fairly well beaten up. Also, there is a crack that runs between two valves. I don't know if they will show up in the pictures or not. So I am guessing a new piston and valves. Hopefully not a new head, what do you think??

[gmctd]

The cracks between the valves seldom cause any trouble - most 6.5 heads will have those cracks - if a crack shows coolant-sign, such as rust and discoloration, then it is a leak, and imo, unrepairable for turbo service

If you don't plan on a complete 8-cylinder re-ring job, hit the local boneyards and get a used piston with similar mileage, so that cylinder will match the other 7 in output - lightly break the glaze on the cylinder wall, check the rings on the replacement piston for minimal ring-gap in the cyl, lightly sand the glaze on them, and you gan go back with minimal expense.

Due to the injection method and light oil as fuel, Diesel rings and cylinders wear minimally compared to gassers (patooie!), as you will see when noting the original hone-marks and minimal ridge in the cylinder - repeated or\and severe overheating is the damaging factor, resulting in collapsed rings and warped cylinder walls

[6.5 Detroit Diesel]

Okay so here is the question. I have three days to reassemble the van. We have a set of 6.2 heads that have only a few little cracks on the precups and none in between the valves. Can we swap over the rocker assembly from the 6.5 heads onto the 6.2 heads safely? The other thing is, we have no access to any junkyards that are parting out 6.5's. Could we pull the damaged piston and the opposing piston and put in two new balanced pistons??

[gmctd]

Won't work, dude - the van heads are specific to the van and hummer - the intake bolt angles are different

Any 6.5 replacement piston should be same weight as oem, so you'll need only one + rings - prollem being, that cylinder could have much greater compression pressure than the 7 worn cylinders if you don't re-ring them all

[6.5 Detroit Diesel]

So reassembling the engine, burnin' the midnight oil, etc, etc. We are cleaning the parts up really good before putting them back in. When we took the injectors out, they were really really stiff. Is it okay to put a bit of Never-Seez on the threads when we put them back in?? The compound is rated for 1200 Celsius. Freaking out over the price that parts stores want for rings. Anywhere from $760 to $840. I don't even want to check out GM after finding out that they want $4400 for the turbo alone. :eek:

[gmctd]

Antisieze is good, but usually not needed as the fuel is a light oil - torque is 50ftlbs

A new set of slugs for the 6.5 is about the same price - you'd think that thing was a Detroit Diesel.

Don't forget to replace all the nylon rocker-keepers.

[Robyn]

Ebay is a great shopping spot for good parts.
My last 6.5 overhaul saw many parts come from there.
Rings were less than $100 from an ebay auction and these were a set of Sealed Power premium rings.

I always use the never seaze on the injectors, does not hurt to use a little on the glow plug threads either.

Just a thought.

Robyn