Loosing Coolant

[dieselluver]

Hi all,
Working on my neighbor's pickup(93 6.5) that had water in the oil and building pressure in the rad. I pulled both heads and all of the lower 4 head bolts on each side had coolant running out of them when I pulled the bolts out. I can't see any real visible cracks on the heads, except for the precombustion chambers. The head gaskets look ok, too. Must be cracked internally? This is the first 6.5 that I've had the heads off of. I've pulled many 3406 CAT heads, but this pickup stuff is kinda new to me. It also appears the rings never seated real good by the looks of the cylinder walls. There was a lot of oil residue from the CDR all the way through the intake. I wish I would have checked for blow-by before I tore it apart. The engine is a GM Goodwrench with about 81k on it. Just wondering if anyone has any suggestions or ideas for me. Thanks for the help.

Dieselluver
Lone Prairie Diesel

[charliepeterson]

Take a real good look at the #4 and #8 valves. These can crack between the valves from heat. How did the head separate from the gasket? Sometimes it's hard to separate cleanly. Does the fire ring look ok?

With only 81K on the clock this truck is just broken in!

[catmandoo]

usually you will have lots of residue in the intake,and what do you mean by rings never seating,(the crosshatch marks look untouched)this is normal even for high mile engines

[dieselluver]

Charlie,

Thanks for the reply. The gaskets didn't fall off, but they weren't stuck, - 'bout like they usually are. The fire rings looked ok, and I am gonna look at #4 & #8 in the morning. Talked to the owner and mentioned the oil from the cdr and he said it had a fair amount of blow-by when you pull the dipstick. Sounds like we might end up putting in a longblock or rebuilding this one. All the other 6.5's I've messed with I installed long blocks. I'm curious how much more of a pain it would be to rebuild this one. A new longblock is SO pain free, if you're not worried about the bill. Any advice is appreciated.

Dieselluver
Lone Prairie Diesel

[Dvldog 8793]

Howdy
I just put a long block in my '99, it had a massive crack in the #3 main web. Started at the piston oiler holes(of course ) and went about 3inches up into the cylinders. My oil level never went up and I never had bubbles in the coolant. Only symptom was coolant loss, about 2 gallons in 200 miles. the new dex-cool mixes with oil rather nice and makes a black oil jelly that fills up the block without increasing oil level! aint that a nice feature! Anyways if you do put in a long block, check my post about block ID. The "good new blocks" are made by navistar. You paymore but supposedly they are crack free.
Have fun!
L8r
Conley Janssen

[Diesel Dan]

Originally posted by charliepeterson:
With only 81K on the clock this truck is just broken in!

Not neccesarily true. Pulled the 6.2 out of my old '88 crewcab with just a tick under 80K. Symptoms were poor starting cold, only. Never started good since I bought it with 42K on it. After trying everything under the sun I finally did a compression check, none higher than 320psi.

Upon tear down all the rings had the chrome chipped at some point on the compression rings. Cylinders looked good but had a minor crack on one of the main webs. Installed a Avant rebuild and starts fine.

Long story short: Don't assume low miles = all OK.

[charliepeterson]

Dan;
How do you like the Unimog? We've got three of them at work. I don't think they are as old as yours but close.

Maybe your '88 had some gasoline mixed in instead of diesel a few times before you got it?

[Diesel Dan]

Originally posted by charliepeterson:
Dan;
How do you like the Unimog? We've got three of them at work. I don't think they are as old as yours but close.

It's an interesting toy. Mine is an "ag" model and only tops out at 35mph or so. Haven't done a whole lot with it yet.

[dieselluver]

Well, I'm getting a set of heads checked tomorrow. They came off my 6.5 that broke the crank, it only had 30k miles on the clock. My neighbor doesn't want to put a lot of money into it, so we are gonna forget about the blowby issue. All these problems remind me why I traded my 6.5 in on a Cummins. Just wish it was pushing a Chevy down the road. Oh, well.

Dieselluver
Lone Prairie Diesel