Thread: Cylinder Compression Test

Why are you looking for problems? stick the old plugs back, change the engine oil and carry on as before. Well that`s what I would do. If it ain`t Broke.................

all are just within 10% so your ok...

Id do a leak down on #3 just to find out where the compressions going.

Thanks guys, will see if I can pick up a leak down tester from an auto shop tomorrow. I might even have enough air fittings in the garage to bodgy something up tonight.

Fuel consumption has been up a bit in the past few weeks and am looking at simple things... might just be some bad fuel, the MAF and/or air filter is filthy.

To do a wet compression test, how much oil should I squirt in the cylinder?

Use a syringe or a bit of clear tube I guess?

Cheers
Paul.

Compression figures look O'k. For a wet test 2 or 3 squirts from an oil can is all that is needed.

Not to much to worry about tho. As others have said "If it aint broke don't fix it "

Gary

less than 10ml but every pot must recieve the same amount...

usually once Ive put it in I turn the engine over by hand 2 full turns before going the starter, this ensures that your not going to "hydraulic" the piston and blow the gauge apart.

I wouldnt bother with a wet test,
Why?;
How do you ensure the oil is all the way around the bore?
Is it a real world test?;
Not really, is it normal to have that much oil on top of a piston?

A warm test is the best way i would say.
Any compression test will give a different reading according to how fast you are spinning the engine.
All compression ratios are is a measurement of volume within the cylinder at maximum (volume) compared to minimum (volume).
You dont seem to have a great deal of variance across the 8 cylinders, up to 10% is the accepted range and beyond this you would probably start to look at valves/rings as a possible problem.