6.9L w/Banks, Fleetguard, 3k mi, crazy high Cr

[batchman]

This is a new to me truck, first analysis was how I bought it and apparently a short run.
It's in a 1986 f350 dually. Engine reportedly was "rebuilt" but I don't know who/what or when.

Second one shows crazy Cr but normal moly. Engine popped a coolant leak in a dry place shortly after oil change, seemingly a cracked head. I'm trying to choose between replacing heads or replacing the engine. If ring wear was the culprit, shouldn't Moly track high too? Could Cr alone indicate high wear at the turbo (again unknown history)? I don't know if the turbo is roller bearing or journal, it's a wastegated Banks Sidewinder.

Click Here - Cr = big problem?

Thanks for any thoughts, I am really a bit stuck on what my next step should be. I think it's pull the turbo and see if there's wear/play evident and then decide repair or replace the engine. I don't want to do the top end then have to go back in 2 years later. For what it's worth, usage is a few K miles/year expecting to haul a slide-in camper and pull an enclosed car trailer.

Best,
- Jeff

 

[Colt45ws]

Thats not..significantly high. With 3 qts of make up, though ehhh..
You also have to remember, they are probably pulling average numbers from their entire library of 6.9L IDI reports; yours has an after market turbocharger on it which isnt going to be accounted for in the average. That engine was N/A stock.

 

[batchman]

Still, searching here and elsewhere I can't find any IDIT or PSD with Cr anywhere near that high.

If it were rings, wouldn't Moly be high too?

Thanks,
- Jeff

 

[sdan27]

No I don't think ring wear would necessarily result in high moly. http://www.eoilreports.com//testPopUps/molybdenum.htm The iron could be from cylinder walls. Hard to say anything from one report. I'd continue and see how it trends. But, if you're looking for something more immediate,it would depend on whatt kind of a deal you could find on heads or an engine. I'd probably look for a known good reman.

 

[bullwinkle]

If the coolant loss is at the head gasket, especially an external leak, could just be a head gasket (6.9s are known for their weak head bolts). If I was to turbo a 6.9 or 7.3 IDI, head studs would be a MUST HAVE!

 

[Jim Allen]

I have the same truck, albeit not a dually, which I have owned since almost new. I put a Gen 1 Banks kit on it in 1987. I overhauled the engine in 2009 due to a blown head gasket (the second set of gaskets in it's life). I never did a UOA on mine when NA and have even forgotten what it was like to have driven it NA but I can tell you the turbo is very hard on head gaskets. I say this to qualify my remarks.

That is not a great UOA. Something is going on here that, IMO, only a teardown inspection is going to be able scope out. If you didn't have the leaking head gaskets, I would say just run another one to verify because if the "rebuild" is recent, it could be break-in material. If the truck was run very hard, it's possible the rings are galled and piston tops are melted due to excessive EGTs but you'd probably have high aluminum also. Ehhh... its really kind of a waste to try and read "tea leaves" from a UOA.

If it were mine, I would first try retorqueing the head bolts and see if the external seepage stops. Then run another UOA and see. I replaced my head gaskets in the early '90s due to this and it was a common problem for that year and a lot of them were done under warranty using an improved gasket. I doubt the head is cracked. It's not common for the '86 era castings (assuming it still has an '86 engine). Only the '83-84 era heads were notorious. The gasket is very likely due to stretched head bolts (or improper assembly, etc.) FYI, the standard/stock head gaskets should be replace during a rebuild. Some guys cheap out on that and somebody lives to regret it. Again, the ARP studs are the sure cure.

If you are considering major engine work, here are some suggestions:

Consider rebuilding this one as opposed to buying a reman. Why... because if you have this one rebuilt, you can install ARB head studs. A vital necessity IMO with a turbo engine.

Don't consider going back to NA... you won't like it. It's not monster powerhouse now and it will be a slug by comparison as an NA. Stock- 175 hp, 360 lbs-ft. Banks kit- 255 hp. 550 lbs-ft. You choose. With head studs and decent quality parts, the turbo engine is as reliable as the NA. And you can improve it from there.

If the teardown shows a non-rebuildable engine, do what's necessary to get head studs into the reman. If you keep the turbo, the reman warranty might be voided. Some of the "volume" companies have done that to folks in the past, so you might as well just add the studs before you install the engine. You don't need to pull the heads to do it but some disassembly is required.

PM me if you want to give me casting numbers and I can tell you if it's an '86 engine.

 

[Jim Allen]

Correction on my post above. I should have said REPLACE THE HEAD BOLTS WHEN INSTALLING A NEW HEAD GASKET because the old ones get fatigued. Again, the ARP head studs are much, much better.

 

[bullwinkle]

Jim will correct me if I'm wrong, but I'm 99% sure that a 6.9 has thinner (as in WEAKER) TTY head bolts than an N/A 7.3 diesel-that's why ARP studs are a necessity. You won't like going back to normally aspirated-I have 2 N/A IDI diesel pickups, and they are SLOOOW when loaded or pulling a trailer! Good news is the 6.9 has thicker cylinder walls than an IDI 7.3, so the block is less likely to crack when turboed, just have to get a set of studs-worth their weight in gold!

 

[Jim Allen]

Bullwinkle is correct, which is why you replace the OE style 7/16" head bolts. They are not "TTY" but they might as well be.

 

[Jim Allen]

Batchman where are you? I love these old engines and I am anxious to hear what happened.