Volkswagen: No compression 3 & 4 cylinders, vw type 3, neil ellis

Question
Hi
I am working on a 1800 type 3 engine, twin carb with balance pipe, fitted to a 1975 SP2.
I find that numbers 3 & 4 cylinders have no compression, I present number 3 or 4 piston to TDC at firing stroke, lock the engine in gear, and apply compressed air into the spark plug hole, the air comes out of everywhere.
the history of this engine is that the engine has never been stripped, but has been standing for a number of years.
This is the second VW type 3 I have seen with identical symptoms, but the only common factor is that both engines had been standing for years.
Can you help in this matter
Regards
Neil Ellis


Answer
Hi Neil,

The best thing you can do is a final check prior to removing the engine:

QUICK TIP:

Remove the valve cover.

See if any valves are stuck open,  by doing a valve clearance test.  If so, you may have lucked out, and may be able to get the gum out of the guides.

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Second, you may be using TDC for cylinder #1, which would leave the valves open on 3 & 4, thus giving the impression of 'air everywhere'.

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FINAL AND LAST OPTION:

Go get (or borrow) a compression tester.

Screw it into the spark-plug hole of number 3.

Disconnect coil

Turn over engine:  Reading should be from 85-120 PSI

Repeat process on cyl. #4.

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If all this fails, time to take the motor out, and I'll be glad to help you along if this is the case.

Keep me posted and good luck.


Ron

P.S.  This isn't really common on Type 3 engines.