Compression test 1.9DG...

[amazingdave]

Hiya,

My van has noticably lost oomph over the last few months so I decided to do a compression test to see what's what....

The results were:

1 9.5 bar
2 11.4
3 11.4
4 10.6

All of the cylinders came up to pressure in 3 compression strokes (engine run for 20 minutes about 2 hours before test) except for no 1 which came up erratically in about 10 compressions.

All of the cylinders lost pressure at about the same rate.

I put 2ml of oil into No 1 and it came up to 10.8 in 3 compression strokes.

So....

I'm thinking worn bore/ rings in No 1.

I'm also thinking that it's not enough to account for the lack of oomph, better get the timing checked and service the carb I guess. (All ignition components are new ish).

What I really want to know is, can I get away with leaving it alone for a while?or is it an urgent thing?

[Fritz]

Try to find a VW friendly garage who will be willing to carry out a CLT ( Cylinder Leakage Test ) as this will give you a definite diagnosis rather than a general idea with a compression test....

Regards


Fritz,,,,,,,,,,,

A compression test will not tell you anything you didn't all ready know.

[sezicoolcat]

Numpty question about compression tests generally - can it be done on your own, without the aid of an assistant? Thinking of doing this on my van, but no-one will be around to help.

Sarah x

[CovKid]

No. Really needs two people to note fluctuations and ensure you're getting a proper reading. Should be easy enough to find someone just to turn your engine over for you though. Rope in a passerby.

[amazingdave]

So, does this mean I need to get a "CLT" to know whether this is an urgent thing or a save up for a 2.1 in 6 months after a summer of camping thing?

[Fritz]

The CLT is a more reliable method of fault diagnosis, thats all.


Regards


Fritz,,,,,,,,,,

PS, but what happens if you end up with a tired 2.1,,,,,,,,,,,,,, it will be no better than a good 1.9,,,,,,,,,,,,,,, think about it.....

[tonytech]

Numpty question about compression tests generally - can it be done on your own, without the aid of an assistant? Thinking of doing this on my van, but no-one will be around to help.

Sarah x

I have a pushbutton switch that I connect from the battery +ve and the spade connector on the starter motor.
Means I can turn the starter over without the 5 yard dash, It doesnt disconnect the fan motor, radio, headlights etc, but I find it pretty usefull.

T