Solving mystery of WBX stretch bolts - need experts ASAP.

[IdahoDoug]

SO. The good news is I have found that Cylinder #1's connecting rod is in fact markedly loose. The engine's in the engine stand, heads off.

I was able to sneak a long extension past the piston and get a socket on the con rod bolts and loosen the nuts. I am tempted to take the nuts off and simply pull the piston out for a quick look at the bearing surface of the crankshaft. It's either OK and worth continuing the project, or the cranks beat up and I either teardown my spare engine or make a date with machine shop to save it.

Anyhow, can someone tell me what will happen if I release that connecting rod cap? Will it fall down into the oil pan or onto the camshaft and be hard/impossible to get out? If it falls down there, it could potentially also jam the camshaft such that I can't get as many tools down in there to retrieve with the other 3 pistons still in place.

So, what would you guys do. Dave and a few of you guys have been through this, so what say ye?

Either in 5 more minutes I will pull the piston out and:

1 - Find it's worth working on and I can get the cap out without dropping.
2 - Find it's worth working on but the cap's fallen into the engine.
3 - Find it's trashed the crankshaft and who cares if the cap falls in.

Thoughts?
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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, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[djkeev]

Small hands, a magnet on a stick, or if the worst happens, the engine is on a stand and can be rotated to retrieve the nuts and cap. (FYI..... Oil spills out)

No worries, forge ahead!

Dave
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Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[borninabus]

maybe too late, but i would disassemble the engine properly using a slide hammer to remove the wrist pins through the water jacket.

the rod cap will likely stick to the crank when and if you remove the rest of it.
if the the rod was loose, the crank is damaged.
this is not an area for half-assery
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88 Van WBX, A/T - 13 JSW TDI 6M/T - 2012 Touareg TDI Sport

[T3 Pilot]

If you decide to remove the piston/connecting rod assembly, then a tip I learned is to go in with an extension and a wobble/u joint on the end and inside the socket (14mm I think) I insert a small magnet and that controls the nut and prevents it from dropping into the case. Not the end of the world if it does, you can fish it out with a magnet tool.

The connecting rod end cap will just slide around the crankshaft, it is big so it's not going anywhere. Just reach in and press it up against the crank journal and spin it around to where you can pull it out of the case.

If things look ok then pull all the rods and replace the bearings.

Lots of cleaning to be done......

Have fun van brother.
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1988 Vanagon

The most important part in every vehicle is the nut behind the wheel......

[djkeev]

[borninabus]

it's much easier to measure a crank when it's not inside the engine case...
seriously, how can you measure a journal for roundness when it's inside the engine

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88 Van WBX, A/T - 13 JSW TDI 6M/T - 2012 Touareg TDI Sport

[IdahoDoug]

Crud,

So, I took the advice to go for it and haven't checked back since. Ironically, it was my 15yo son who came up with both the wobble and the suggestion to put one of his rare earth magnets in the socket. Worked a treat - great suggestions from you guys. Got all the pistons/rods out without messing with the wrist pins.

So the bummer is the crankshaft took some damage on #1. This is at my limit on wrenching because it requires machine shop skills - correct measurements and such. Its enough damage I can feel it. The rod bearing on the cap was reduced to a thin shell but complete. The bearing on the rod side takes more abuse so it was thinner yet and missing about a quarter inch of one end that was feathered down to a razor edge. The crankshaft journal is dull, and has vague grooved undulations. The nuts were tight, but the other 3 were tighter still. The other 3 crank journals are glossy and good.

On the con rod and cap, they have a similar surface to the crankshaft journal - gentle undulating vague undulations. Not sharply defined scoring.

I wondered as someone voiced if the crank has bearing material deposited on it, due to a harder crank vs bearing, and if so, if that means there is a good chance the crank can be saved by machining this off. If both surfaces get hot enough during this metal melting episode that it doesn't matter - then that would be good for me to know.

I have two choices and am looking for a cost guess on one:

1 - I can split the case and bring the crankshaft to a machine shop for them to resurface the damage. Anyone familiar with such a process? Would they machine all four con rod surfaces to the same diameter, or just the one and then I'd need an oversize bearing for that single one? What does something like that cost, or an hour time guess based on whether they have to fully machine the whole crank or a single spot repair?

2 - I can strip down my spare engine to the same point and if its crank looks good, rebuilt it instead with the new connecting rods and correct bolts sitting on the bench. That bums me out a bit because I have no idea what I will find in there and what the miles/history is. Plus the nostalgia factor of having the original engine I wanted to do. Or, I can split its block as well and use the crank in my original block.

What say ye?

PS - I thought I'd add that I'm not confident of my wrenching skills to split the case, so I was planning to avoid that all along. I'm not confident of my ability to install new cam and crank bearings. So if anyone has any thoughts on the "real" difficulty of this, I'd appreciate it. I'm a "take notes and bag and label every little bit" guy so if that means I might pull it off, I'd like to get any perspectives. Thanks. Previous to this, my high water mark was successfully replacing the 3/4 slider in my Syncro trans. Which terrified me!
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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, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[tjet]

How far is Walla Walla from you? RJE would be who I'd call. They sell a nice 2.2 kit.

[djkeev]

At the point you are at, it's no harder than an old Air Cooled.
Go ahead, crack the case, see what is inside.

Nothing to lose........

There's no magic to main and cam bearings...... BTDT many times on Air Cooled.

Dave
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Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

Beetle
https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[IdahoDoug]

I think I'm going in. Cruised a few threads where people could not get the block apart. Hope I don't have those issues. Any other known 'gotcha's?
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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, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[AtlasShrugged]

Idaho ..sorry to hear about the engine..

Was the rod becoming noisy? With that amount of wear I would think it was knocking. I think you said you discovered the problem when you saw metal in the oil?

Splitting the engine cases should not be an ordeal. If you need a crankshaft I have a spare you are welcome to. Be sure and source your rod bearings while working with the machinist. Size and availability will matter.

[Zeitgeist 13]

This thread title seems a little misleading, since I doubt the stretch bolts are the source of your issues...as I highly doubt they're the cause of most MV shortblock failures.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[Wildthings]

[fraggle00]

Dive in. Buy the whole engine seal kit for $120 or so from van cafe.

I rebuilt mine with new AMC heads, van cafe rods, new oil pump, new rings, new relief spring and new seals. Left the camshaft, camshaft bearings, crank and mains alone. I did disassemble the news heads, worked over the keepers and hit each valve with a little grinding compound. Test fit all the wrist pins on the rods using my drill press and oil to make sure nothing bound up. Close to 1,000 miles in and still running nice. Hope it stays that way.

I did have to seal the case three times and reinstall the rods a bunch before I got it right, particularly around the cam plug. Make sure you fill it with some oil before you go through all the work to put the heads back on! If I was closer I would come and give you a hand, my newly found skills are already atrophying.

The case comes right apart if you get all the lots and nuts out. If you miss even one it will fight hard. Use dental floss or fish line to check if you aren't sure, long hours and grime can hide simple things.
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'91 Vanagon Carat
'87 Porsche 928S4 DOWN
'12 Fiat 500 Abarth

[AtlasShrugged]

I always wondered about the dreaded "rod stretch bolt failure" in the WBX engines.

VW, Porsche and Audi used those rod stretch bolts in many engines..including the 911..which never had that problem..unless someone re-used the rod bolts in a rebuild and re-stretched them (a grenade..always waiting to explode..and always did..sometimes years later) . They were designed to be used once.

My thinking is somewhere in the engine's history..maybe even while being serviced under warranty..the rod bolts may have been re-used.

Anyways..I am surprised that Idaho's engine was not knocking..should of been clattering with the clearances he had.

[Zeitgeist 13]

Color me skeptical of the stretch-bolt theory. I'd be curious to see an autopsy of a 2.1 with a snapped rod bolt and largely intact rod bearing material. I strongly suspect that in most instances where the rod lets go, the engine ran low on oil and/or really hot, and the bearing surfaces became compromised, creating excessive clearances and a rod that began inertially rocking around its crank journal, putting stresses on the bolts and cap. Similar to how the vast majority of rods let go on all manner of engine designs.
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Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[vanagonjr]

[Wildthings]

I have personally owned two 2.1 engines that experienced rod bolt failure. The first engine was in a Syncro I bought after it had experienced a failure of the bolts on one rod, all three of the other rods and bearings were in good condition and could have been rerun. The failure was the bolts snapping without the engine having been run long enough once failure began to get the crank hot as it was not discolored. The bearings inserts were beat to shit but most of this appeared to have occurred right as the bolts let go as the bearing lining was essentially all there just mashed badly. I knew the original owners of this rig and know the engine had never been rebuilt except to have the heads gaskets replaced. There were 147K miles on the engine at the time of failure.

The second engine is a 2.1 which which I had owned from new, it began to loose oil pressure at hot idle at around 180K miles. This engine was taken out of service before it blew. I have never rebuilt it but have taken it down and the noticeable failure is the nuts on one rod were loose and there was some wear showing up on the insert, there was no sign of the journal having gotten hot. I haven't miked the rod journal but it looks like I may be able to rerun the crank without machining it. The other bearings in the engine were fine.

I like to run comparatively thin mulitgrade oils, like 5w40, in my engines which may have given me more warning of the pending rod bolt failure than people who believe they must run 20w50 or other overly thick oils will get as the bolts begin to stretch.

[IdahoDoug]

Can anyone tell me if there is a visual difference to the 1.9 bolts commonly used to update away from stretch bolts? I am thinking of pulling one rod on my recently rebuilt spare engine, and taking a look now that I've found a way to easily do that without separating the piston/rod (its a simple matter of using a universal extension to get to the con rod bolts).
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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, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[insyncro]

Hand planked and over stretched, one hell of a rebuild