I want to do a compression test on my engine but it won't start. What drawbacks are there when doing a compression test on a cold engine. Is there anything I should watch out for?

 

inacurrate readings

 

You will usually get a lower reading with a cold engine. If it has not run in a while you may have an issue with some of your rings sticking and giving you really low comp readings. Spray a little brakekleen (two seconds worth or so) in each cyl, crank it over until the cyls dry out, pour a tablespoon or two of engine oil in the cyls, crank again, and you should be able to get a pretty good comp reading

If your car won't start and you are thinking it might be a compression issue pretty much anything in the tripple digit range will fire an air/fuel mixture.