Itinerant Air-Cooled

Been having some issues with the Bus. Burning oil. It's coming from the tailpipe at start up and in short bursts when accelerating. Also experiencing a big loss of power. And it's making a chugging / knocking noise that goes in & out. Of course it wasn't happening at the Lab on Saturday when everyone was there to hear it. Pulled the plugs today and found this.





#3 is oily & #4 is completely covered in baked on oil! I'm thinking valves or rings.

Ideas?

Rings AND valves? I'd suspect both.
Compression test next. But all that oil came from somewhere...
1 & 2 side looks pretty clean.
Looks like you gotta pull that engine and strip it down to rods and see what's up. Or put another engine in and diagnose at leisure, if an option.
The chugging/knocking could be from a dead cylinder. Remember, the pulled wire that didn't do anything?
Onward, good luck. Is the bus still drivable?

Sluggo wrote: chugging / knocking noise that goes in & out.
#4 is completely covered in baked on oil!

Do not drive it. That knocking noise is carbon trapped between the piston and the cylinder head. You are close to damaging the piston that may only need a re-ringing, and you are close to cracking a cylinder head.
Check the valve guides when you have the head off for any that have come loose from the head.
Colin

Amskeptic wrote:

Sluggo wrote: chugging / knocking noise that goes in & out.
#4 is completely covered in baked on oil!

Do not drive it. That knocking noise is carbon trapped between the piston and the cylinder head. You are close to damaging the piston that may only need a re-ringing, and you are close to cracking a cylinder head.
Check the valve guides when you have the head off for any that have come loose from the head.
Colin

Won't drive it. Guess I'll be borrowing Hambone's garage for a while. Good thing I renewed my AAA a few days ago.

Is it okay to do a compression test right now or should I just strip it down?

hambone wrote:Remember, the pulled wire that didn't do anything?

That was #4. Guess that plug explains it.

I'll call you tonite. I do need the garage back soon to build a roof rack and other things but can spare a few days.

hambone wrote:I'll call you tonite. I do need the garage back soon to build a roof rack and other things but can spare a few days.

Could it be long enough for me to drop the engine, have heads rebuilt (if need be) and reinstall? I can drop & reinstall in two days. The rest would be having them rebuilt (if need be).

Hopefully I'll just need to replace the rings. But I have a gut feeling about the guides. Could the guides let that much oil through to the combustion chamber?

Yikes!

At least Bertha isn't camped in town. Good luck Sluggo.



neal

Sluggo wrote:

hambone wrote:I'll call you tonite. I do need the garage back soon to build a roof rack and other things but can spare a few days.

Could it be long enough for me to drop the engine, have heads rebuilt (if need be) and reinstall? I can drop & reinstall in two days. The rest would be having them rebuilt (if need be).

Hopefully I'll just need to replace the rings. But I have a gut feeling about the guides. Could the guides let that much oil through to the combustion chamber?

You will know you wrecked a piston if the top ring is seized in the upper groove. Check the gap very carefully if it is not stuck. That means the crown got hammered down.

Guides will show up upon inspection . . . and yes, the intake guide sucks oil right on in, you can see a big black beard on the offending intake valve down at the neck of the stem. Good luck.
Colin

I'll be having the Bus towed to Hammie's tomorrow morning. Then I'll spend the day tearing it down & taking pics. I'll post em here as I go.

Anyone know a good place to get my heads worked on in Portland? Guess I'll get my flywheel & pressure plate balanced while I have the engine dropped.

Halsey said they are trying out Central Cylinder Head but have not seen the results yet. Fix Um Haus was recommended for turning & balancing the flywheel. Anyone had any experience with these businesses? Where's a good local place to get parts (seals & rocker shims)?

Halsey for the parts. I've also heard that an employee of Discount Import does VW machine work: Mike 503-626-7036 x101
I have no personal experience however.

Sluggo wrote:I'll be having the Bus towed to Hammie's tomorrow morning. Then I'll spend the day tearing it down & taking pics. I'll post em here as I go.

Anyone know a good place to get my heads worked on in Portland? Guess I'll get my flywheel & pressure plate balanced while I have the engine dropped.

Hambone's the best . . .

Please carefully disassemble so your forensics will not be disturbed. You will see if carbon has gotten squished between the head and the piston at the quench area. If so, look carefully at the ring land clearance all the way around the circumference of the piston.



The more likely area will be along the bottom quench area (green with purple arrow)
but possibly along the top (yellow with red arrow) , hoping that one of these four colors will help our color blind mechanic distinguish.
Colin

Groovy. And time is running backwards to commemerate daylight savings time.
And I ain't sayin nuthin about a dropped engine saved by a mounting stud.

Pulled the engine yesterday. Forgot a few things that were different about this Bus compared to my old one. Like the fuel line going through the tin. This was holding the back end of the engine up in the air. We didn't notice so when I pulled the hose the engine dropped, fell off the jack and hit the concrete. Luckily it landed on the stud and that took the force of the impact. Gotta replace the stud but the outcome could have been much worse.

Exhaust on 3/4 side showed lots of oil. Exhaust manifold on #4 was covered in oil & those two nuts were loose.

I'll be pulling the head today.