850R compression test

[Giles]

I have bought a compression tester and plan to put it to use once I have my car back from it's rebuild. Question is, how do i use it and what am I looking for? This is the one I have bought

http://cgi.ebay.co.uk/Am-Tech-Petrol-Engine-Compression-Tester-Kit_W0QQitemZ150472700238QQcategoryZ0QQcmdZViewIte mQQ_trksidZp4340.m506QQ_trkparmsZalgo%3DNGRI%26its %3DI%26itu%3DUA%26otn%3D8%26pmod%3D300448667212%26 ps%3D63%26clkid%3D6703554239237343145

I know about removing the plugs, taking a fuse out and something to do with the fuel pump, but what should the compression readings be?

[5seaterT5x2]

dont know anything about fuses or fuel pumps etc, but as long as the readings from each cylinder are all very very close n similar think thats about it

[t5 pete]

You will need to dissconnect the injectors in the haynes it also says to dissconect the rpm sensor then remove the plugs and screw in your compression tester and get some one to hold the throttle wide open and crank the engine for 3 turns i think the compression should be between 11-13psi in all bores

[Giles]

ah ok - i was going by this

http://volvospeed.com/Repair/compression_test.html

not sure which method is right, but the haynes manual should be......

[Giles]

ah ok - i was going by this

http://volvospeed.com/Repair/compression_test.html

not sure which method is right, but the haynes manual should be......

btw - he didn't say in his guide what the readings should be, only that they should be within ~5% of each other....what if they are not?

[Volvostorm]

btw - he didn't say in his guide what the readings should be, only that they should be within ~5% of each other....what if they are not?

Means you have a compression leak, normally through the valves, rings or head gasket

[Giles]

Means you have a compression leak, normally through the valves, rings or head gasket

OK - thanks. Best do the test first and I'll post back what I find.....