Compression Test Results

[1_eyed_jim]

Cold 1.9DG 1986 engine code 16732

1 = 120 psi
2 = 115 psi
3 = 120 psi
4 = 130 psi

Anything to worry about here?

[kevtherev]

nope..

[1_eyed_jim]

nope..

Happy days

[Dazco]

Just a query , does it matter if the engine is hot or cold and which is the best for a reliable figure .

[kevtherev]

Best done on a warmed up engine with a dry test.
plugs out
ignition disconnected
fuel system disconnected
full throttle
crank the engine to turn over five times, take the last reading.
record the first compression.

Your cylinders should be close to the specified compression pressures specified by the manufacturer. More important is even compression between cylinders. If the lowest cylinder is more than 20% less than the highest cylinder it can cause the engine to run rough.

The First compression should be at least 50% of the fifth, on that cylinder. If the first comp is well over 50% of the final reading, but the final reading is low, that cylinder is likely leaking past the valves.

read this in the wiki
https://club8090.co.uk/wiki/Te ... on_testing" onclick="window.open(this.href);return false;

[123-jn]

Mine were between 130 and 150 psi before I had a waterjacket leak and rebuilt the engine. It ran Fine. They are definately more now as its much more difficult to turn over with a spanner. I haven't tested them yet as the rings are probably only just bedded in. The good news is that even when yours do become too low a new set of rings is probably all you will need. My bores were measured 'as new'. I have heard that they run OK down to about 100psi.

[1_eyed_jim]

So looking at my readings the engine looks like it's nearly ready for some new piston rings soon? The compression rise on cylinder to was 25 - 50 - 75 - 100 then 115 psi (recorded on video)

[kevtherev]

It was done with a cold engine so the results are not conclusive

[Dazco]

Thanks for that explanation kev

[1_eyed_jim]

It was done with a cold engine so the results are not conclusive

Ok I'll do a warm test as soon as

[1_eyed_jim]

Garage warm test results. Rather worried about these but he wasn't

1 = 90 psi
2 = 110 psi
3 = 90 psi
4 = 120 psi

[1_eyed_jim]

Garage warm test results. Rather worried about these but he wasn't

1 = 90 psi
2 = 110 psi
3 = 90 psi
4 = 120 psi

From what I've read it's brown pants time if the lowest reading is 20% less than the highest reading and brown trousers time if the readings fall below 100psi

Help

[kevtherev]

pants..

[1_eyed_jim]

pants..

Pants? What the readings? Any advice on what to do next please? Thanks Rob

[Dazco]

How's the van running mate ?