how to check compression
Moderator: martauto
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iamjj
- E30 Zone Newbie
- Posts: 141
- Joined: Tue May 31, 2005 11:00 pm
- Location: Maldon, Essex
as the subject says really, whats an easy way to check wheather i have compression on a non-starting engine
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mrLEE30
- E30 Zone Team Member
- Posts: 6589
- Joined: Tue Jan 18, 2005 11:00 pm
- Location: Sweating buckets in Bahrain
You need a compression gauge. remove all six (or four) spark plugs, screw compression guage into each sprkplug thread in turn and crank the engine for a couple of seconds. this will give you compession values for each cylinder. Not sure what the value should be as i mainly work on two stroke boat engines, but basically you are looking for similar figures for all cylinders, one being low means head gasket gone, piston rings broken, piston broken, etc etc etc......
You can also do a leak test where you crank each cylinder until full compression on the gauge then time how long it takes to drpm to half its value. this give you an IDEA of the condition of the bores.
obviously you will need the started motor to work to perform these tests.
mrlee
You can also do a leak test where you crank each cylinder until full compression on the gauge then time how long it takes to drpm to half its value. this give you an IDEA of the condition of the bores.
obviously you will need the started motor to work to perform these tests.
mrlee
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Wilson
- E30 Zone Regular
- Posts: 725
- Joined: Sat May 21, 2005 11:00 pm
- Location: Ipswich
:yeahthat: But pull the lead of the coil, as the engine only needs to turn over not start...
BTW What should 325i M20 engine be???
BTW What should 325i M20 engine be???
