Compression Test

[dobboy 231 2 Cars]

If i wanted to do a compression test with engine out car, with box/starter attached would it just be a case of removing all spark plugs, putting 12v from a battery onto starter and solenoid?

 

Would the engine need oil in it? etc

 

Is it just a case of applying the feeds and reading maximum reading when it turns over?

 

Tia

[dcc 855]

I wouldnt use the starter personally, I'd crank it using a wrench on the crank pully, but if your lifters are empty you'll be waiting a while either way

[dcc 855]

and I wouldn't try turning it over without oil tbh!

[dobboy 231 2 Cars]

What do you mean lifters?

 

And how do i overcome that?

 

Better/easier to do a leak down test instead?

[dcc 855]

Depending on what you're trying to accomplish?

 

I am guessing you're afraid of damaged valves from your previous thread.

 

doing a bit of reading on the web, it suggests for the engine to give accurate and reasonable results you need the engine to be at operating temperature, minimum of 300rpm on the engine.

[dobboy 231 2 Cars]

Yeah, just want to make sure everything is tickityboo before i drop it in.

 

I'm sure it is but would hate to be wrong.

[Dizzee stuff 33 1 Cars]

If the valve is only slightly bent a compression test will show you nothing, you need a cylinder leakage tester and even then could be inconclusive if only very slightly bent.