2000 3500 diesel questions

[ttyR2]

I may have the option to buy a 2000 Chevy 3500 4WD truck for a song. The engine supposedly has a broken crank though I'm not sure how that diagnosis was made. In the case of a broken crank, is the block automatically a write-off? When one of these cranks breaks, where does it usually happen? I'm assuming the engine is a 6.5TD.

Is there an average cost for a shortblock?

[ronniejoe]

In most cases, the crank breakage is secondary. The block cracks, allowing additional flexing in the crank leading to a failure of the crank.

I would bet that the block is cracked badly in the center three mains.

Where is this truck? If you don't buy it, I might be interested.;)

[Robyn]

RJ is pretty close on the mark. This said, I have seen a few 6.5 engines that broke cranks and the block was fine without even a crack anywhere.

There seems to be little predictability as to what you will find when you get it open.

Now here are some big IF's

IF the engine speed was low when the crank let go and the thing was shut off before it beat itself to death the outcome can be fairly good.

Took one apart recently that was broken at the number two main, right where the main journal fillet joins the counterweight.

The block had a small crack through the outer bolt hole on that main web but no others.

We did the Lock and stitch inserts on all 6 of the outer holes on the inner 3 mains, dropped in a Scat crank and the sucker is back in the ball game.

Cleaned the heads up, washed the block out good after the inserts were installed, fresh rings and bearings, new head gaskets and such along with a new set of head bolts.

The engine was in a 95 Burb with 157K miles on it.

Engine was turning at near idle speed when the crank snapped. The owner shut it off right away.

Now I have seen others that literally tore themselves to shreds on the inside.

The only way to know for sure is to do a Post mortem on the little creature and see what you have.

If the main webs have large cracks that extend below the bolt holes or originate at the register fit of the main caps then its game over.

If the main bore/bores have been torn up, same deal, game over.

If there are small cracks that are centered in the outer bolt holes of the center mains, and they do not extend below the depth of the bolt hole, the block can be fixed with the Lock and Stitch inserts.

A good hot tanking and magnafluxing is a great starting place.

If the block is a squirter style, be sure there are no cracks in the area of the oil squirt holes. These are a death knell.

The early 506 squirt blocks were notorious for cracking though the squirt holes and then up into the cylinder walls. :eek:


Unless you can afford to spend the $$$$ on a fresh AMG/GEP engine, I would stay away from the off the rack short blocks.

I have personally done several 599 and 929 blocks with the Lock and Stitch inserts and the repair is simple and effective.

I would not spend a dime on an early 506 squirt block (97 production)

IMHO a 599 or 929 block that has the inserts installed is a great way to go.

You can do this, install a scat crank and then reuse most of your other parts. (Any rods damaged may need to be replaced)

OBTW 6.2 rods are a direct swap. I used a set in my DaHoooley 6.5 build last summer

Another Buggaboo is that the later blocks 98 and later, can also crack cyl 8 at the top and it is a game over, unless you want to try a sleave.

Hope this helps, keep us posted

Missy

[ttyR2]

If I'm hitting the right link, the Scat website seems to be down. Do they offer a forged steel crank to replace the stock cast one, or just well-prepped stock cranks?

[HH]

Where is this truck? If you don't buy it, I might be interested.;)

I'll second that, my truck is getting pretty rusty.

[Robyn]

Jusrt checked, site still down.

The scat cranks for the 6.5 are a cast steel unit as opposed to the factory nodular Iron.

They are not as good as a Forged crank but they are a good deal for the $$$


Peninsular diesel sells a forged crank for about $900 plus shipping.

These are a great crank but pretty pricey.

I have seen several of the scat cranks and they are a nice piece for around $400.

These should be ballanced though rather than just dropped in.

Missy

[ttyR2]

I'm still waiting to find out if the deal is a go.

I may have the option of a '96 3500 as part of the deal as well (diesel engine). I drove that one on a 400 mile round trip a few years ago and it had an overheating problem. I didn't bury the temp gauge in the red but caught it when it was heading that direction. Topped off the water level after it cooled off, but it still wouldn't do over 57mph on the highway without the temp coming up, but ran fine otherwise for the 150 miles left in the trip. This was after it supposedly got a new factory engine installed. I don't have any idea if that one had updated parts or if it was a 6.2 or 6.5.

If I have a pressure test done on the '96, should that tell me if it has a cracked head or block? Or would it have to be at running temp to know for sure (let the cracks open up with the heat)?

[ttyR2]

Are the engine block and cylinder head ID numbers easy to find with the engine in the truck? If so, where do I need to look? I want to find out if the '96 has the updated block/heads and whether it's a 6.5 or 6.2.