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This happened to another local TX 928 owner and the damage was done within less than 10 miles.
Trey - I sent you a link to a 91 block with good bores - call me if you need help jumping on it.
Beer and Pizza will guarantee a 928 gathering and we can start pulling it all apart.
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Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Damn, knew if I tossed that 5.0 block that someone would end up needing it.
Sean, has it been a week yet? You know what I'm talking about. You keep something around for years, then you finally toss it. A week later, you find that you need that piece that you tossed the week before.
I just did that with some of my special plane spares, and now - I'm going to Houston to look at another plane. Just when you thought you were out -- they pull ya back in.
Perhaps I should have lived with the pealing paint. Lesson learned the hard way.
Well, too late for you and my sympathies, but there are other paint options and it is the fault of the painter here, or did he warn you to look for debris, probably not? Not that I think you can go back to him for redress.
Engine out and completely dismantled. What I find it the following:
The main issue is seized rings. Every compression ring is totally seized and "collapsed" or forced in the grooves so tight that it is hard to find the separation point where the ends meet. I had to drive a small screwdriver in the separation point and then drive them out of the slot. You can see the remaining ring in this piston.
The removed rings have a build up of carbon link deposit with a very, very fine grit.
Removal of the ring was by force to the last millimeters. The middle ring was seized on all but 1 cylinder (the one with the best compression). And even the oil sweep rings were seized on many cylinders. I tried soaking them in parts cleaner, gasoline, penetrating oil, and heat - nothing loosened them.
The fine grit is what I felt on the cylinder walls that felt so dry.
Anyway, this total ring compression allowed the cylinders to ride fully on the cylinder walls and the walls are worn shiny from the brief start and repeated effort to start. There are a few deep gouges in the lower portions of some cylinder walls that I think is from the piston skirt wearing against the wall.
The crankshaft is beautiful. No sign of wear, no scratching, no burnish marks at all. The main bearings look like normal wear to me.
If the debris came from the intake as I believe it must have, I am a little worried about valve wear and remaining debris. I cant really sink a fortune in the car and stay married so the total conservative refurb and/or replacement of any possible components that might fail is really not an option for me. I would like to be reasonable but frugal.
So, what the debris is - I cant say. Overspray from powder coat? It is too fine for blasting media unless it disintegrated in the chamber somehow. My dad even asked if I had any enemies that would had added sugar to my tank... Is it loosened carbon from the intake loose but not dislodged in cleaning the intake?
Perhaps the thread is helpful for someone in the future.
I still have not split open the oil filter. Not really sure how to do that without adding shavings. Any suggestions?
Most unfortunate and you have our sympathies- must be a gut wrenching thing to experience. We seem to be having a spate of this type of failure assuming it is linked to the inlet manifold coating.
One has to wonder just how far/deep the debris has reached into the engine before considering refurbishment. If the damage is limited to the pistons/bores a rebore and new pistons may be viable but...?
Wishing you a speedy and not too fiscally challenging path to a full recovery.
After you removed the rings, did you clean the groove on all foreign material and reassemble the rings to see if the were still binding? Maybe between your the carbon build up and foreign material, it caused the rings to seize immediately.
Me, I'd get a piston groove cleaning tool, clean each ring groove, check clearances with a new set of rings and see what you get. Your picture is pretty poor, you must have gone to the same photography school as me, so it is hard to see the piston condition. Now, if they are boogered up...then scrap the whole cleaning the groove idea. But, if they are okay, and I would assume no material got into the wrist pin area, taking into account the short run time...I'd clean the living daylights out of everything, check and recheck, re-ring the pistons, have the heads freshen up (new guides and valves resurfaced) and reassemble.
Now, all of this is subject to finding foreign materials in the oil. If material is in the oil...then be certain to clean crank ports, check the oil pump and bearings extensively.
I have a powder coated set of cam covers and intake manifold I've been meaning to swap into my trusty 89. They've been sitting around my house for the last year or so. Although I was going to wash them a bit first, I wasn't fully aware of how insidious the blasting media can be in hiding out inside the manifold until the recent spate of incidents like the case in hand.
I remember long ago working on another 928, installing a refurbished manifold and still finding gritty powder on my finger when I rubbed the inside after a washing. Didn't think too much of it. Washed it again but with no particular extra efforts. It seemed clean but I didn't particularly investigate some of the hidden areas around the bell ends of the passages that appear to trap media according to some reports. Oh, as far as I know that engine didn't fail anytime soon after the rebuild, but I think I'll just skip this essentially cosmetic change for a while longer until I'm confident I know how to clean the parts.
I have a powder coated set of cam covers and intake manifold I've been meaning to swap into my trusty 89. They've been sitting around my house for the last year or so. Although I was going to wash them a bit first, I wasn't fully aware of how insidious the blasting media can be in hiding out inside the manifold until the recent spate of incidents like the case in hand.
I remember long ago working on another 928, installing a refurbished manifold and still finding gritty powder on my finger when I rubbed the inside after a washing. Didn't think too much of it. Washed it again but with no particular extra efforts. It seemed clean but I didn't particularly investigate some of the hidden areas around the bell ends of the passages that appear to trap media according to some reports. Oh, as far as I know that engine didn't fail anytime soon after the rebuild, but I think I'll just skip this essentially cosmetic change for a while longer until I'm confident I know how to clean the parts.
Glass bead is evil stuff. Sorry to hear that something nearly invisible blew your baby up. The guy who did the work should eat this. The parts should have been thoroughly cleaned after coating. Between the glass and the polymer going into your notes the heat probably caused the mix to fuse together and seize those rings right in their grooves. Terrible!
03-10-2016 | 11:44 AM
George Layton March 2014
