Checking valve guide wear

[daverclasper]

Hi. I have had on Vitesse, no2 cylinder spark plug oiling, up for a while now, after slow city driving (burns off on faster runs).

Without removing the head and dismantling the collets etc to free the valve, Is it possible to get some idea of possible excessive wear, by rocking a valve side to side, or will the spring tension not allow this?.

I will probably live with this anyway, as still runs fine (burns a bit of oil), though interested if it can be checked to some extent, next time rocker cover is off

Thanks, Dave 

[Pete Lewis]

Dave  I dont think you will detect much while the springs are under load 

its really a head off  pop the springs off and give the valve head a wiggle 

there may be some better ideas like pressurise the cylinder with a compressor down a  plug hole

may allow collet removal ( not easy) and give the stem a wiggle or fit a seal 

thats a long shot  i would advise carry on driving till the head does need removal

Pete

[JohnD]

Pete,

Completely agree that guide wear cannot be assessed with the springs in place!

But pressurising the chamber may check valve seal on the seat, but will not pressurise the intake or exhaust ducts and cannot check the guides!
Remove the springs - best done with the head off - and wiggle them by hand.  ANY free play is too much!

Dave,

Consider piston ring wear.  You can check for this without disassembly.  Check the compression pressures.     If No. 2 is low then check again after a teaspoonful of engine oil down the plug hole.  If the pressure rises, all is well.  If it does not then a valve is not sealing.

John

[daverclasper]

Thanks guys.

John, I did a comp test about 3 years ago (before I noticed the oily plug issue developing) just for general interest. Looking at the figures I wrote down, no2 was at the higher end of figures that were within 10% of each other. An average of 190 (though I guess the gauge reading high).

Of course some engine wear/damage could have occurred since then.

I will do another comp test, when have a some time.

Could it be possible that just the oil ring on no 2 has failed/or carbon stuck, therefore burning oil, though compression rings/bore ok?

It has always used some oil (since 25,000 miles ago when I bought car) and has sometimes/often, smoked a bit at idle and when revved up a bit.   Never appears to smoke noticeably, when started from cold, even after a couple of weeks..

No big deal for me, I don't think. Just interested and enjoy learning.

Edited January 21 by daverclasper

[JohnD]

Dave, 

The absolute number that a compression gauge shows is meaningless!  It's the relationship hhe others in the same block.yhst is revealing.   And as you have more recently found this oiling, its worth doing the test again.  Please review the method (many descriptions on-line) and practice it three or four times to ensure consistency.

Good luck!

John