2.25 petrol 5mb 8:1 compression test

Greetings. Just did a compression test on my new landy. I warmed her up for about 10 minutes, and the tested all cylinders at near as damnit 130PSI each (128-131). They didn't seem to immediately lose pressure once I stopped cranking the starter, which I would assume is a good sign, but maybe it's a bit low across the board? I didn't do a wet test unfortunately, as I was trying my girlfriends patience by making her crank the starter whilst I did the readings Any thoughts on whether I've got anything to worry about here?

Sounds pretty healthy to me as they are even and pressures not bad.

A wet test would tell you if you are leaking any pressure past the piston rings/oil control rings, but to be honest yours sounds OK.

Just out of interest, why were you testing?

Are you having running problems?

Mark

You have a serious problem here. I would recommend a recon or a good used replacement. The engine sounds OK, though.

why serious problem

Hehe. Thanks for the replies! I was testing because the vehicle is new to me, and it does have a couple of running problems. the main one is that it splutters and lurches sometimes when you floor it, usually worse going up hill. I get a lot of popping coming from the exhaust on overrun too. I haven't looked into many of the causes yet, but someone lent me their compression tester and needed it back pretty sharpish, so that's why I've done the test

I have to say that the spark plugs looked really good when I had them out though

Once I've actually looked in to all the usual things I'll probably post again.

oxides - Your post seems to be a complete contradiction, and makes no sense whatsoever - thank you

tombardier said:

oxides - Your post seems to be a complete contradiction, and makes no sense whatsoever - thank you

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Think he was attempting some form of smart arsed comedy!!

i'm wondering if my compression test was low because I didn't have the throttle depressed when I did it? I've only just read in the manual that that is what you're meant to do. I've given the gauge back now though

tombardier said:

i'm wondering if my compression test was low because I didn't have the throttle depressed when I did it? I've only just read in the manual that that is what you're meant to do. I've given the gauge back now though

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Probably having throttle open would have helped get the figures up but the most important thing was that they were even.

Mark

Im sure i read that 8:1 should be about the 160psi mark.

yes it should be. I'll borrow the tester once more and do it again whilst the throttle is depressed. the pressures will be lower because I didn't do that before!

If it's popping and spluttering you might want to look at the carb or inlet manifold 'cos it might be sucking in air somewhere. If you're going to play with land rovers you'll need a more patient girlfriend.

spluttering and backfire under load is usually the condenser if its an older type Dizzy.

I need to have a look at which type of dizzy I've got actually. I'm going to replace the condenser, points, sparks, coil and leads in one go. will see how that goes I haven't got much history with the vehicle, so it needs to be done along with all the other things I haven't got around to yet like doing my gearbox oil!

Did another test today with my foot on the throttle and got between 160 and 165 psi across the board. pretty pleased with that!