M110 (Euro) compression test
 

Hi all,

I've just got #whether it's anything to worry about at the moment or whether an 'Italian tune-up' and a regular tune up might improve matters.

I only did one round of tests (the battery doesn't seem in top condition and it's cold so I didn't want to flatten it). Results are:

#1 - 110
#2 - 110
#3 - 110
#4 - 120
#5 - 105
#6 - 100

The plug in #6 is very back with carbon, and the car does smell like it's running a bit rich. #2 plug is a bit black and oily.

I got the car recently from an auction and it seems to have been sitting around for a while; I think it could do with new plugs and air filter, and if I'm feeling flush new plug wires, rotor and cap. looking at the pistons through the plug holes they look a bit carboned.

I'm thinking that it's probably worth at least changing the plugs (and possibly leads etc) and giving it a bit of a run before thinking about doing an HG job. I might have to try to get someone to do a leakdown test as well (I don't have a compressor).

Does this make any sense to anyone? I think my figures are low and have seen a few posts about M110s needing a bit of a thrashing every now and then.

Anyone think I'm on the right/wrong lines here?

Mike

check the valve adjustment first. they do look low, i would assume that carbon build up on the pistons and valves would make the euro numbers even higher than normal. like 160 and higher for a euro, easily. the bottom end is virtually bullet-proof, so rings and/or pistons would be a suprise, unless oil changes were ignored. also, make sure the cam lobes are not flat on the intake side. if the air can't get in, it can't be compressed. good luck, chuck.

A bit low, do a valve adjustment on the motor. I know my motor has 145-150 on all 6 cylinders and its US spec motor.

Thanks guys,

Was planning on doing a valve clearance adjustment fairly soon in any case - I know these engines are noisy but there seems to be a clatter that sounds like one valve in particular is out more than the others (sounds a bit like an injector ticking).

I think the one cylinder with the particularly carboned plug might have a leaky injector. Once I've got an electric fan on it (visco fan was seized) I'll put some fuel system cleaner through it and give it a good run. hopefully with that, a general service, and a valve adjustment it'll start running a bit better.

Mike