Help! Dead Cylinder!?

SoSlo · Joined: 08 Mar 2004 Posts: 25 Location: Spokane WA

It appears that the engine in my bus has problems. Here's what I know:
1970 Westfalia Campmobile - Stock
1600 cc Type 1 single port engine - stock w/ Pertronix ignition.
I purchased the bus nine years ago with a rebuilt (who knows what that could mean?). There's no doubt that the engine is tired.

The problem is low power and an uneven exhaust pulse.
I've checked the spark from the coil to the spark plugs and that's OK.
I've done a compression check three (3) times and each one shows no compression in cylinder #3. A few squirts of oil in the cylinder doesn't change the compression reading in #3...still zero.
I checked the valve clearance on the #3 valves and the exhaust valve had no lash (???) so I readjusted to .006" but that had no effect...still no compression in #3.

The engine starts just fine and idles great...no unusual sounds, no rattles or any metallic clanks...just purrs with an uneven exhaust.

I'm no mechanic and I've never opened up a VW engine so my diagnostic abilities are very limited. So does anyone have any ideas as to what could be the source of my problem? Any suggestions on a solution?
Any help would be appreciated. Thanks.

Tom

Troy Hobbs · Joined: 05 Aug 2003 Posts: 766

If it had run long with no valve lash (valves should be adjusted every 6000 miles, or at least checked once a year if you don't drive much), it probably has a burn't valve. That or a hole in number 3 piston can cause no compression.

Sprø Norsk · Joined: 24 Aug 2005 Posts: 331 Location: Oly

If it still runs as smooth as you say it does you might get away with simply pulling the head and checking it out...replacing what needs to be replaced. (Piston, valves, what have you...)

SoSlo · Joined: 08 Mar 2004 Posts: 25 Location: Spokane WA

I adjusted the valves last summer so I'm sure that I haven't driven 500 miles since the adjustment. The zero valve lash was a recent developement.

Would anyone recommend a local shop/mechanic to take the bus to? I think this is beyond my abilities.

thanks,
Tom

jengel451 · Posted: Sun Apr 18, 2010 2:47 pm Post subject:

While it's running, open the oil filler, see if it's blowing out there, if it's really bad, it's a piston.

Agree with Troy though, sounds like you could have a burnt valve/holed piston.

Troy Hobbs · Joined: 05 Aug 2003 Posts: 766

Valve could have stretched then. Could have a crack or a loose seat to.
Any way you look at it, at least the one head needs to come off to see.

SoSlo · Joined: 08 Mar 2004 Posts: 25 Location: Spokane WA

Thanks for the suggestions. I'll check the oil filler blow-by as soon as I can.

The head can be taken off without removing the engine, right?
Should both heads be be done at the same time or can I do one head (if that corrects the problem) and leave the other alone?

I forgot to mention the compression test results:
#1 120
#2 124
#3 0
#4 131
That's an average of three tests but each cylinder was very consistent.

any suggestions on local mechanics/shops that are reliable/honest/knowledgeable/affordable and get the job done in a timely manner?

Troy Hobbs · Joined: 05 Aug 2003 Posts: 766

Engine needs to come out to remove the heads. If the head needs to be replaced (you might be able to repair this one still), it would be wise to do both.

SoSlo · Joined: 08 Mar 2004 Posts: 25 Location: Spokane WA

Well, it looks like I've got some decisions to make....thanks to every for the imput....maybe I'll buy a lotto ticket!