Zero Compression?

[Goach2]

So I'm not experienced in compression testing, I'll say that right out. I bought a gauge and am about to put some money into parts, so I thought it would be a good time to test it.

Following one of the instructions I found posted on here, I removed all the spark plugs and made sure noting was going to fire. Cylinder one came in just under 50lbs, with not the best battery. For some reason, the other three cylinders didn't even register on the gauge? I'm assuming, if I did it correctly, then all three cylinders have stuck valves? I took one of the valve covers off and cycled the engine again. Should it be making a racket with a stuck valve? Because it didn't sound like anything out of the ordinary. Do I have to take the rockers off to determine if a valve is stuck? Or is there a way I can tell without disassembling? The engine has sat for a few years, but overall seems to be in pretty good shape. I'm hoping it's just stuck from sitting and I can knock it loose? I'm hoping to get it running before tearing it all down for a rebuild.

Thanks!

[Tram]

What year?

I'm guessing '78/'79?
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[Goach2]

Sorry, it's a '77 2.0L FI

[Wildthings]

Have you driven your rig? If it runs normally making good power then your compression is probably fine.

[Abscate]

It's easy to Fubar a compression test so get someone experienced nearby to give you 10 minutes of guidance

If it's a runner, your compression is nominal at least
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[williamM]

If the little Schroeder valve in the gauge is stuck open- you get a wildly fluctuating needle and a zero result.- maybe the first cylinder blew some carbon in there???
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[Goach2]

Wildthings - No, this has sat for more than a few years, likely indoors for most of it though.

Abscate - Thanks, I wish I had someone to refer to...

williamM - I thought I might have screwed it up, but when back on #1, it did 50lbs again...

If valves were stuck, would it be difficult/noisy to turn over?

[kevin77westy]

Good point about the compression gauge maybe not working right. Maybe test it on a good motor to verify its working as it should.
Did you adjust the valves before the compression test? I assume you have solid lifters in your 77 2L but maybe not. If you keep getting low numbers then you might have dropped valve seats. You can check for this by taking off the rocker arms and putting a ruler across the valve ends to see if any are sitting low. One could also argue that if you are going to rebuilt anyway then why bother. If you have a head or P&C problem (hole in piston, bad rings) you will see that when you start taking it apart.

[KentABQ]

1977's had the GE- code engines installed, which have hydraulic valves lifters.
Since the vehicle has sat for years, the lifters are compressed fully, which makes a compression test impossible to perform, doesn't it? I've never had hydraulic lifters, so this is just a guess on my part.
_________________
-Kent-
1976 Riviera, 1.8l FI chrome yellow VAN - "Chloe"

"I must say, how can you be in a bad mood driving this vehicle full of vibrant color.
Cars of today are so bland in comparison. It's like driving a celebration!" ---WildIdea

Bus ownership via emoticons:
---williamM

[Abscate]

[kevin77westy]

Hydraulic lifters started in 78 but who knows what it has now.
Is your compression tester a threaded one or one of those crappy ones with a stopper like end?

[Goach2]

Abscate - I would give you a thumbs up if I knew how.

This is a threaded gauge.

[lil-jinx]

If you have an air blow gun with a rubber tip,you can blow air into a spark plug hole with the valves in the closed position,if air come out the intake then the intake valve is open,if it comes out the exhaust then the exhaust valve is open,if it comes out the oil fill pipe then the rings are not seating,if it comes out around the cylinder at the head or case then the heads are loose.
Your engine may have sucked some crap in from the intake[mouse house] being open all those years.Maybe remove and check the intake runners.
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1974 Bay Westfalia. she likes to be called Ethel.
1968 Dune Buggy
1974 parts bus
A smart man learns from his mistakes,a very smart man learns from other's mistakes.

[SGKent]

hydraulic lifters started in 1978, Some GD motors came with them, some did not. What the cut off serial is doesn't seem to match the Factory service manual Supplement because it implies GE was the first hydraulic. VW sometimes held the surplus over for Westfalia conversions.

Back to the zero compression on 3 cylinders. Most unusual. Might be time to get a HF video camera and look into the cylinders. maybe the valves are stuck open from sitting. That or a busted crankshaft - lots of possibilities here including bad heads or a bad gauge. I don't think 3 seats would fall out at once.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[Wildthings]

Read up and do a valve adjustment, not an overly hard thing to do. You will need to determine for sure if you have solid or hydraulic lifters. The main thing is to verify that you are at TDC compression for the cylinder you are adjusting the valves on. You can do a visual on the amount of thread showing above the nut on the valve adjusting screw to get an idea on the condition of the head. All the screws should have about the same amount of thread showing. If one or more screws is showing an extra couple of threads over the screw that shows the least, then you likely have a valve seat(s) that is recessing into the head.

[jtauxe]

^^ this

Definitely do a valve adjustment before anything else.
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John
"Travelling in a fried-out Kombi, on a hippie trail, head full of zombie..." - Colin Hay and Ron Strykert
http://vw.tauxe.net
1969 Transporter, 1971 Westfalia, 1976, 1977, 1976, 1977, 1971, 1973, 1977 Westfalias,
1979 Champagne Sunroof, 1974 Westfalia Automatic, 1979 Transporter, 1972 Sportsmobile, 1973 Transporter Wild Westerner, 1974 Westfalia parts bus, 1975 Mexican single cab *FOR SALE*, 1978 Irish 4-door double cab RHD

[WhirledTraveller]

All good advice.

Would be helpful to know more about the motor. The engine code, is it installed in the bus, why was the motor parked, etc. etc.

Basically you can have zero compression for several reasons which you need to narrow down.

1) Faulty tester. You can test your tester on another vehicle that you know is good. Like your daily driver.

2) Flat cam. Basically the cam could be worn down to the point where it doesn't open the intake valves anymore. If you turn the motor by hand, you should see the rocker arms going up and down.

3) Hole in the piston. Typically caused by a valve or valve seat that came lose and exited through the piston top. Unlikely in 3 cylinders at once, because after 1 fails the motor doesn't run much longer.

4) Really bad rings. One quick test is to squirt a teaspoon of motor oil into the cylinder and see if the compression comes up. If it does, suspect the rings.

5) Valve that doesn't close all the way. This could be caused by a really bad valve adjustment (i.e. someone did it very wrong) or by the valve being help up by a piece of carbon or something between the valve and the seat. If the valve can't close all the way, that cylinder can't develop compression. Sometimes the valves sink way into the head due to overheating, and then the valve hangs out in midair and can't close all the way. This often results in the valve itself overheating (because it needs to contact the valve seat in order to cool), breaking, and making a hole in the piston.

6) Hydraulic valves that bled all the way down and are adjusted wrong. Hydraulic valves have a different adjustment procedure than solids. When they are bled down from sitting, they will have reduced compression, but you should still have some compression. If they are adjusted wrong, you might get no compression. Only sure way to know whether you have solid or hydraulic valves is to pull one out... which isn't terribly difficult... but you can get a pretty good clue by looking at your pushrods. If the pushrods are steel, probably hydraulic. If they are aluminum, probably solid.

To pull a lifter out, you unbolt one rocker arm shaft and remove it, then pull the pushrod out, and the pushrod tube you gently twist and pull out through the head. Then a magnet on a stick works well to pull the lifter out of the case.

If you have hydraulics, read this:

http://www.itinerant-air-cooled.com/viewtopic.php?t=11408

'77 Should have solids originally. But most of these motors have been rebuilt, and some builders love to change things up according to their preference.
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1977 Westy, Automatic. Big Valve heads, CS Cam.

[Abscate]

[Wildthings]

[Goach2]

Lots of good suggestions. I'm going to start with a good battery tomorrow. I like the idea of the air pressure in the cylinder to when valves should be closed. perhaps I'm not getting a good seal with the gauge too. I don't know how everyone gets it down under the shielding on 2 & 3, but I did it by feel

Abscate, I'm about 20 mins from the border. You're welcome anytime!