Piston sleeves corroded solid, how screwed am I?

[4Gears4Tires]

I read a bunch of old threads, read through the always helpful http://www.benplace.com/vanagon_engine1.htm write up. A lot of advice was, "don't let the sleeves come off!" well... let me let the pictures speak for themselves.

I can't even get them apart on the bench. I am currently soaking them in PB blaster. The corrosion/rust is crazy, I've never seen anything this bad. The good news is that the cross hatching looks great and the pistons popped out with a very audible "pop" so that's nice. The oil came out disgusting and so did the coolant. All brown. Doesn't look like any cross contamination between the two, just brown for different reasons. Gross. At least I bought all new hoses, pipes, and a radiator so on reinstall it'll be a lot cleaner.

Looks like the only way to reinstall the sleeves is to remove the pistons at the wrist pin, install piston into sleeve, and then reinstall wrist pin. At least I don't have to worry about timing.

I have the cylinder head gasket kit, hopefully it will include all the gaskets I need. I don't think I will be able to get any quick parts right now, lol.

Anyone else run into super corroded piston sleeves? Any advice besides don't remove them from the engine?
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'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[DanHoug]

they'll clean up fine. since you got the pistons out, the bores are likely fine aside from normal wear you should mic for. whack them off the heads, which are likely trash anyway, and hit the water jacket side with black oxide blast media. they'll be purrty when done.

heat the heads/cyls up somehow... on a grill, in the oven, etc... you want a hot chamber, not pinpoint heat but even that would sorta do but with more risk. then whack the cylinders back and forth with that deadblow hammer you have. do NOT use a metal hammer as the cast iron cylinders will shatter.
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-dan
60% of what you find on the internet is wrong, including this post.

'87 Westy & '89 Westy both 2.1 4spd

Past projects can be found at--
www.thefixitworkshop.com

[Steve M.]

The alloy cylinder head will heat up and expand faster then the steel cylinder sleeves if you apply heat to the head..
Maybe if you get a cooler full of ice water and set the head across the top with the sleeves well down into the ice for a good while to contract in the cold and then heat the head you might have a chance of the head expanding with the heat to break the bond.
If your in snow country that might work as well as a cooler full of ice water.
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This free advice is worth exactly what you paid for it.

There are seven days in a week. Someday is not one of them.

[mikemtnbike]

I’d trust whatever dan says he’s been posting about waterboxers since the 90’s. Give his method a shot.

What’s the backstory that led to this situation? Just curious, I’m guessing a motor that sat for a while with water no or minimal coolant in it.
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1991 Vanagon GL 2.1 AT Westfauxlia. "Frankie" Totaled https://www.thesamba.com/vw/forum/viewtopic.php?t=764510&highlight=carnage
1995 Eurovan Camper "Marzivan"
2020 GTI SE manual

[4Gears4Tires]

Not sure on the whole history. I think the motor had sat for a year before I bought it and then it sat for at least half a year in my garage, but that shouldn't have led to this situation. It also should have been filled with actual coolant, not water, because it came from NY. I've seen motors sit for 10 years and the water jackets look better. Plenty crusty dried coolant boogers, but not the titanic. The seller said it was weeping coolant in one spot and showed it to me. Obviously I should have taken it apart before installing it the first time, but I got impatient. I'm over a year of van ownership at this point, maybe I'll get to enjoy it in 2020!

I will give heating the whole cylinder head in the oven a try.
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'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[IdahoDoug]

Not sure why this works, but a machinist showed me this more than 40 years ago. Rather than pound a stuck circular object back and forth at 180 opposite sides to loosen it like logic might dictate, pound it every 30 degrees or so in a constant circle. As if you're trying to make it go around like a child's top wobbling. It will feel like you're getting nowhere for many revolutions but it is slowly loosening.

Since you're this close, consider spending $40 on new rings, and $50 on a ball hone to quickly and easily resurface the cylinder walls. I or others can guide you and with a ball hone you can literally almost not do it wrong. I had my 16yo son do 3 of them just so he could say some day he'd honed cylinders!

Let me know and I'll give you the correct hone and company.
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1993 Toyota LandCruiser, 2002 BMW 325iX, 1982 Toyota Sunrader

[4Gears4Tires]

I am happy to report that giving it 4 soakings of PB blaster over yesterday evening and then a generous application of the deadblow hammer from many different angles popped the cylinders off after considerable effort. I did not hold back with that thing. My friend was holding the cylinder head to the bench and I channeled my inner Thor. The cylinders cleaned up fairly well in the parts washer and wire wheel.

What I am not happy to report is that Dan was right. The heads are trash. Once I cleaned them up I found this between all 4 valves. Nice fat cracks. Quite a lot of pitting too.

Well that sucks. I guess it would explain why I thought the 2.1 FI was pretty sluggish in comparison to the 1.9 carb motor I pulled out. I considered pulling the heads off the 1.9, but ehhh at this point I don't care enough. I am cleaning the 1.9 motor up, replacing all exterior gaskets/seals, and installing it with the the 2.1 FI stuff. Hopefully it runs ok under FI. It ran great as a carb motor. Whatever. I am not having it sit on the lift for weeks while I source new heads, rings, crankshaft bearings (they're toast), and whatever else I'll need. Besides, I do not want to rebuild a waterboxer, that was the whole reason I bought a "ready to go" 2.1 in the first place!

Look at all this trash. What's everyone's opinions on getting the heads welded and machined vs new pricy AMC heads? Of course, it might not be possible to machine out the pits without going below thickness spec.

The 1.9 had a massive front main seal leak, so I still have more cleaning to do on it. The heads are still dirty, but I got the block cleaned up ok. I need to transfer over the new clutch and pressure plate as well. The front crank bolt took wouldn't break free with a 450ftlb impact, a 750ftlb impact... it took a 1200ftlb impact. The plan for tomorrow is finish cleaning up and replacing seals, paint/reinstall intake, and reinstall the motor.

What a freakin disaster.
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'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[IdahoDoug]

Ehh, I wouldn't worry about the cracks. Many people here are driving around with them and have no idea. It's very common and VW even addresses it in the FSM saying something along the lines of "small cracks are OK" or somesuch.

The cracks would not impact performance, so don't blame sluggishness on them, either.

More importantly are the pits. Many have used epoxy to fill them after properly cleaning the pits, then sanding back down to a smooth surface. That area is just a sealing surface for the water seal, so not majorly stressed. I used JB Weld, which is a high quality epoxy.

This is not a highly stressed engine - just a plodding low power output mill.
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1993 Toyota LandCruiser, 2002 BMW 325iX, 1982 Toyota Sunrader

[dabaron]

tencent has a great deal on AMC heads... i'd pony up and get those and enjoy some happy motoring.

glad you got them apart, it was without a doubt the most difficult part of my engine rebuild.
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1991 Vanagon GL Camper
i had no idea i wanted to be a mechanic

[4Gears4Tires]

So I got the 1.9 block buttoned up with all the 2.1 FI stuff. Started on the first try, how crazy is that? It must be a christmas miracle! It died immediately after, but it starts right up. That is 90% of the way there! I think the timing is off, I had to swap over the distributor because the other one had the vacuum advance on it. I have not retimed a waterboxer before, but I think that is the next step. Also, the throttle pedal opens the throttle body about 1/4 way when its full on the floor. I will need need to look into that so I can unleash all the ponies under the hood.

How hot does the head have to get to melt plastic? It ran and idled just fine after the over heating episode too.

I am considering buying GW's piston/cylinder combo, new journal bearings, and heads and putting the 2.1 back together so I can do another engine swap. Joy. But if the 1.9 runs well, that will be very very low on my priority list.
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'87 Syncro Ferric Oxyhydroxide Superleggera Edition
'85 Westy Sciuridae Domus Edition

[tencentlife]

Over 500ºF.

https://en.wikipedia.org/wiki/Nylon_66

Alu melts at over 1100ºF so there's a big margin between the two. If there was no water in that juncture with the proximity to the #3 exhaust port I could see the surface temp getting hot enough to soften that material, if not melt it.

Damage at that flange is one of the signs I look for to tell me the engine was overheated. Mostly I see signs of softening, creep, and embrittlement. The bleed hose flange at #2 suffers the same way if it's the nylon 6,6 part, but that part has long been available in steel so probably not many original nylon ones left in service.
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