TheSamba.com Forums
 
  View original topic: compression test Cant Be Right!?
sharkskinman Thu May 10, 2012 10:05 am

so on the gauge i have (hoping it was screwed in all the way)

#4 70-75
#3 70-75
#2 70-75
#1 55?

SamSmith Thu May 10, 2012 10:13 am

Buy or borrow a different gauge to be sure. Your gauge could out of calibration. If not youre probably gunna be tearing down the top end.

RafCarre12 Thu May 10, 2012 10:48 am

it HAS to be out of calibration... at least I'd think that because 3 of the 4 are spot on (if you add 100 psi)

Max Welton Thu May 10, 2012 10:49 am

Holding the throttle open while cranking, right?

Max

Nate M. Thu May 10, 2012 11:53 am

Max Welton wrote: Holding the throttle open while cranking, right?

Max

To get real numbers the motor must be warm and have the throttle wide open and let it crank for about 5 seconds. You should also do a good valve adjust before doing the test. Normal numbers on a stock 1600 should be between 125-135 all the way around.

sharkskinman Thu May 10, 2012 1:21 pm

Cold engine, just did valves prior to test,(most were tight )
brand new (cheap) compression gauge. First time using.
All plugs out foot on open throttle.

Maybe not tight enough in the spark plug hole.

SamSmith Mon May 14, 2012 8:03 am

Get it figured out yet?

sharkskinman Mon May 14, 2012 8:32 am

no
ive been so busy i havent had time
2 jobs and VW work on the weekend

will try this week

raygreenwood Mon May 14, 2012 4:41 pm

sharkskinman wrote: no
ive been so busy i havent had time
2 jobs and VW work on the weekend

will try this week


You should have the car warmed up or the rings are not seated. Leave the spark plugs out and throttle open. Discon nect the three pin plug from the distributor so you are not injecting fuel and pull the hot wire from the coil so there is no spark. I will bet its better when you do that. Ray

KTPhil Tue May 15, 2012 9:55 am

And count a full six pulses to make sure it gets up to its full potential pressure.

On your tester, do you have a rubber dome or a thread/o-ring seal in the spark plug holes?

sharkskinman Tue May 15, 2012 8:21 pm

thread / o ring
and next time im going to put a hair of oil on the o ring

its just hard to get it snug twisting the hose with the tins on



Powered by phpBB © 2001, 2005 phpBB Group