compression test

Discuss mechanical problems here.
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
Post Reply
steve c
Minor Friendly
Posts: 76
Joined: Fri Jan 20, 2012 3:16 pm
Location: Peterborough
MMOC Member: No

compression test

Post by steve c »

hi, just done a compression test, engine hot, all plugs out, throttle fully open, i got readings of three at 125 and one at 130, engine pulls like a train, with plenty of torque, are these figures to low and should i be worrying? i do get a bit of mayenaze in the filler cap, but i only do very short journeys. regards steve

Tom and Maria
Minor Fan
Posts: 153
Joined: Mon Feb 13, 2012 8:22 pm
Location: Devon
MMOC Member: No

Re: compression test

Post by Tom and Maria »

They are quite low but if it is pulling well and not losing/ burning too much oil then personally I wouldn't worry.
bmcecosse
Minor Maniac
Posts: 46561
Joined: Wed Feb 16, 2005 11:24 pm
Location: ML9
MMOC Member: No

Re: compression test

Post by bmcecosse »

They are low - not quite 'desperately low' - but headed that way...... But if it's going well. Be happy!
ImageImage
Image
chrisryder
Minor Legend
Posts: 2217
Joined: Mon Nov 15, 2010 11:44 pm
Location: West Midlands UK
MMOC Member: No

Re: compression test

Post by chrisryder »

It's only really an issue if one (or two) are drastically lower than the rest.

It's unlikely to be the headgasket causing your mayonnaise, as it wouldn't leak equally on all cylinders. As you rightly say, it'll be due to short journeys.
steve c
Minor Friendly
Posts: 76
Joined: Fri Jan 20, 2012 3:16 pm
Location: Peterborough
MMOC Member: No

Re: compression test

Post by steve c »

thanks for the above comments, only wish i had not bothered doing a test now, but idle hands and a few hours off!! , but as it does not use oil, or water, plugs are nice and clean, + nice clean exaust, think i will leave alone and just monitor it for a while, thanks steve

katy
Minor Legend
Posts: 1092
Joined: Sat Mar 14, 2009 2:50 am
Location: Red Deer, Alberta, Canada
MMOC Member: No

Re: compression test

Post by katy »

Any chance that your compression gauge is reading low? Seems a little strange w/everything else in good order.
Talk slow, think fast!
liammonty
Minor Legend
Posts: 1205
Joined: Mon Apr 23, 2007 2:32 pm
Location: Dartmoor
MMOC Member: No

Re: compression test

Post by liammonty »

I really wouldn't bother worrying if the engine runs really well, but: a) did you do the test with the throttle wide open? and b) did you do the test with a nice hot engine, or with it stone cold? Could make a difference.
steve c
Minor Friendly
Posts: 76
Joined: Fri Jan 20, 2012 3:16 pm
Location: Peterborough
MMOC Member: No

Re: compression test

Post by steve c »

hi compression tester is new, ( does not mean its accurate though) test was done hot, and throttle wide open, but as i said it goes well so i will just keep an eye on it, i have had the head of recently and stripped the valves out, cleaned, and regrouned them etc, could be i didnt do to good a job there ??

bmcecosse
Minor Maniac
Posts: 46561
Joined: Wed Feb 16, 2005 11:24 pm
Location: ML9
MMOC Member: No

Re: compression test

Post by bmcecosse »

I'm sure you did - have you retorqued the head and set the gaps correctly?
ImageImage
Image
Post Reply