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  View original topic: I take it this isn't good... I need help, advice, an engine? Page: 1, 2  Next
fukengruvenoval Thu Sep 06, 2007 5:25 pm

OK. I bought this bus nearly 2 years ago. It's a '76 Westy with the 2L. We've put thousands of miles on it and done lots of work. Currently it's running better and cooler than ever.

I have changed the oil regularly, every 2500 - 3000 miles. This time I decided to clean the strainer (I finally got around to buying the gaskets) and this falls out:





The quarter is there for scale... Looks like the skirt of a piston to me??

The thing is, this stuff could have been there for 10,000 trouble free miles, or 1. I have no idea. The engine has had a top end rebuild at some time, for all I know this could be a broken skirt from the old pistons...

I'm sure the suggestion is going to be to pull the engine, dismantle, inspect, and go from there?

Please help, and soon.... I guess I'm cancelling the camping weekend, and likely the rest of the season...

busdaddy Thu Sep 06, 2007 7:14 pm

If it's been going this long and isn't making any noises I wouldn't lose any sleep over it. It does look like a piston skirt but it also looks really old, unless I'm seeing things.
Do the edges look like fresh breaks?

bustadons Thu Sep 06, 2007 7:15 pm

if the van runs problem free, then why worry? That stuff could have been there a long time. I found a washer in my strainer, couldn't tell ya how it got there. More important CHECK your fuel hoses and make sure they're tight. Unlike me who almost had a 1971 VW toastermobile.

fukengruvenoval Thu Sep 06, 2007 7:21 pm

Well, first two replies are pretty good... It does look like an old break, but I am no expert. I just thought I might be further ahead stopping everything now and inspecting rather than trashing the case and possibly other parts down the line...

This engine had a top-end rebuild before the PO bought it. I have a receipt from the builder, a Toronto shop. I know it's common to smash the piston skirt on the case when removing cylinders, I wonder if they did this and didn't see the break?

I am flirting with the idea of running for a few miles, draining oil and strainer, repeating a bunch of times until no more metal is found... Replace the filter on the last change and do a good run before checking again. If no more metal is being produced, maybe it's an old problem and I can get a pile more use out of this thing???

Thoughts?

dweller Thu Sep 06, 2007 7:37 pm

just out of curiosity, and to give your question a kick, how many ways are there to nick a piston skirt? I know it's possible to during rebuild, but afterwards?? I'm just trying to picture where and how it could happen in a running engine.
Is it common to have a skirt chip off during engine operation? and wouldn't that be a situation where a rod threw or something (which you aren't experiencing from what i'm reading).

just curious.
dp

fukengruvenoval Thu Sep 06, 2007 7:46 pm

dweller wrote: how many ways are there to nick a piston skirt? I know it's possible to during rebuild, but afterwards??

I'm equally curious, hoping some of the elite will chime in with their two cents... I thought the only way would be during rebuild, and since this one had a crappy top-end only rebuild, it is likely??

1975 Kombi Thu Sep 06, 2007 8:16 pm

I have heard of piston slap. I very worn engine starting in cold weather. The pistons will slap the walls until the engine is warm. Once the pistons expand then the slap stops. Nice to see another Canuck in the bunch.

Mark Thu Sep 06, 2007 8:46 pm

I wonder:
1. How long it's been like that,
2. Is the piston skirt strength compromised/stress fractured? :shock:

busdaddy Thu Sep 06, 2007 9:03 pm

With a piece that big missing it would be making a dull thudding noise either accelerating or letting off power. Easier to hear in a water cooled engine but you would still notice it in a type 4.
The only way to damage a piston would be to crack it during assembly, if it's coming apart like that the noises would be getting worse and worse and the pieces would look fresh on the edges.

I suspect a sloppy teardown during the top OH.

dwill49965 Fri Sep 07, 2007 4:40 am

fukengruvenoval wrote: We've put thousands of miles on it and done lots of work. Currently it's running better and cooler than ever.

I guess I'm cancelling the camping weekend, and likely the rest of the season...

I think you've answered your own question. Don't cancel anything. At your next regular oil change, check the strainer again, and go from there.
As others have said, if it was something really serious, you'd have probably found out by now.

Of course, the problem now is that you'll be paranoid while driving it, straining to hear every little noise and change, imagined or not.

Jeff Geisen Fri Sep 07, 2007 5:01 am

... another thing to be paranoid about is the fact if one of your current pistons is missing that hunk of skirt, you have an out of balance situation.

thewalrus Fri Sep 07, 2007 5:24 am

Mark wrote: 2. Is the piston skirt strength compromised/stress fractured?

Good point....I wonder if a compression check would reveal anything??

vdubyah73 Fri Sep 07, 2007 6:24 am

My money would be on a catastrophic failure of a valve or seat being the reason for the top end rebuild in the past. the rebuilder determined that the bottom end was good enough for him and didn't tear it down. What you're looking at is evidence of that.

RUN IT

Bill

1975 Kombi Fri Sep 07, 2007 6:55 am

Just for humor you might want to match it up with a piston barrel to see if the curve is at least correct.

udidwht Sat Sep 08, 2007 4:18 am

That would be cam bearing.

Bleyseng Sat Sep 08, 2007 6:42 am

I would pull it apart because if there is metal like that in my strainer I want to know whats wrong. I hate being towed home any distance. :shock:

Oakbough Sat Sep 08, 2007 2:36 pm

I just saw your pics and I am floored... I found almost the exact same pieces floating around in my motor!
So I redid the top end of my '78 2L a couple of years ago. First time with such a job, thankfully I had some good guidence. After doing all the work, I was putting the muffler on while on the engine stand. I spun the motor around to work on the top side and I heard something metal rattle around inside. I was needless to say, upset. After confirming my delema I proceded to remove the oil strainer and carefully retrieve the pieces. I finally pulled out three pieces, two of which were just like the sawtooth aluminum "piston skirt" pieces you have.

I had replaced the pistons so I inspected the old ones to see if they were from there. The pistons were shot but the skirts were all intact. I decided that the pieces were from an old set of pistons, or from the metal flanges on the case (I assume they are also in the case like they are on the outside bottom) that I assume are there to help cool the oil.

Because I spent all I had on rebuilding the motor, some transmition and front end issues have limited my driving to ~600 miles since then so I am sorry to say that I cannot confirm that all is well and I will not have a re-occuring issue. The pieces I pulled out were really beat up as well so I assume they have been in there for quite a while.

If anything, your not alone.

VWBusrepairman Sat Sep 08, 2007 3:02 pm

I hate when metal gets chewed up inside of the case like that. :shock: Maybe a nice tear-down and rebuild will do the trick.

fukengruvenoval Sat Sep 08, 2007 5:57 pm

Thanks everybody for the replies so far.. I have an update on the situation.

After reading all the posts and having a brief and very helpful email conversation with Germansupplyscott, I've decided to leave the engine in and keep running it.

I drove the bus quite a bit today after cleaning all the metal bits from the strainer the other night and adding new oil. Once the bus was nice and hot I pulled the plugs (all four looked really nice, like the "normal" picture in the Haynes or Bentley manuals) and did a compression test.. Here are my results:

1 - 110
2 - 120
3 - 100
4 - 115

My results after squirting some oil in the cylinders were exactly the same.

I'm not too happy with the overall variance, or 100 on #3. My valves are due for an adjustment (they have slightly over 3000 miles since last time) which may level things out a bit. Also, because my CHT sender is on #3 cylinder I'm not sure I got a good seal with the compression tester.

Through a little stroke of luck I did pick up a zero mile 2L rebuild today from a well-known vw guy. I'm going to get all the odds and ends for this motor and leave it in the garage as a perfect turn-key replacement when mine goes... Then I can start rebuilding mine while the new one is in the bus....

After installing new plugs and firing it back up I changed the oil and looked for any sign of more metal - it was nice and clean. I topped it up again and will run it a bit more, then change the oil and filter again for good measure.

Any thoughts on the compression test?

1975 Kombi Sat Sep 08, 2007 6:35 pm

Did you hold the throttle open during the test and is the air filter new or removed? And I am not an expert but it is how the strokes build the pressure. I think if it is at the top pressure in four equal strokes is the best. If it takes 10 to build to 120 then that is not good. Hot or cold test?


What I do now is place some earth magnets on the oil filter in my newer cars. I don't know if you can attach one to the strainer plate. But it holds all the metal in the filter which is thrown away or clean off the strainer.



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