4.0L oil consumption/burning

[JackstandJohnny]

been daily driving the YJ the last few weeks and the smell of burning oil is now driving me nuts.  it literally reeks in the cab.  at first it was just when i would let off the gas but now its all the time, and even worse when i let off. the only time it smells ok is at idle or revving it while idle. with any load it smells.
consumption is roughly 1L per fillup. i burnt 2L in waiparous a few weeks ago.  its not buring blue very bad; occassional blue puff though.

did a compression test and it was straight across the board at 115 - 120 cept for one cylinder at 100.  (the engine was not warmed up if thats a huge difference or not) have not done leakdown test.
oil pressure is also very low.  don't know if this is common or not.

pulled the spark plugs; they are new, 1000km on them. the plugs from 1 and 6 were oily and the electrodes were burnt. the other 4 were nice and clean.  i'm guessing contamination of some sort, and i'm guessin that oils getting in there somehow.

couple guys (tootsc and the apeman)  are guessing bad valves;  gonna replace these with the pookapotamus on thursday to rule them out.

just wondering if anyone else has some ideas?

cheers

[Pookapotamus]

correction: bad valve seals. its cheep and easy will at the very least let us know if its rings.

[apeman]

Valve seals...and do a quick valve lap while you are there...cant hurt!

[mike s]

Did you switch to synthetic oil recently? Had high mile-ers start using/burning oil when changed over, too slippery and get by wear i guess. Used an oil flush kit on customers car which used alot of oil and had clouds of smoke on start-up, Says it's fixed now.

[The Machinist]

Are you getting much blow by?  If you're pulling the head off to lapp the valves in you'll be able to check the wear in your cylinders.  A mirror finish in the bore is a good indication your rings are not sealing, if there's a big ridge at the top you probably need to bore the block.  If you're not pulling the head check for play in the valve guide while you have the spring off, if the guides are bad the valves will wear an uneven surface in to the seat causing lower compression and you will get oil consumption.  Take a straight edge and line it up along the top of your valves, they should all be within +-.015".  Make sure to use a viton style seal and not an umbrella seal.  Oh yeah, don't forget to put your piston at TDC before taking the spring off.

Ps.  Where's my pilot bearing puller?

[JackstandJohnny]

didn't switch any oils recently.  in fact haven't even had to change it

Jamey, i have the puller, will deliever to you when u have a moment.  that ok?

[Pookapotamus]

we are leaving the head on. sticking an air line to the sparkplug hole and taking the spring off, so we cant lap the valves, and we cant keep the piston at tdc, we have to remove the rockers any way so it does not really matter. but thanks for the advise all

[The Machinist]

Jamey, i have the puller, will deliever to you when u have a moment.  that ok?

Sure, one of these weekends.

we are leaving the head on. sticking an air line to the sparkplug hole and taking the spring off, so we cant lap the valves, and we cant keep the piston at tdc, we have to remove the rockers any way so it does not really matter. but thanks for the advise all

You put the piston at TDC so that the valve will not drop in to the cylinder if the guide is bad, it has no where to go.  Has nothing to do with the rocker arms.  I've all ways done it this way.  

[Pookapotamus]

ah i see what your doing, i have always used ait to keep the valves up and then i dont have to find tdc. i will give it a try thanks
 

[JackstandJohnny]

Are you getting much blow by?  If you're pulling the head off to lapp the valves in you'll be able to check the wear in your cylinders.  A mirror finish in the bore is a good indication your rings are not sealing, if there's a big ridge at the top you probably need to bore the block.  If you're not pulling the head check for play in the valve guide while you have the spring off, if the guides are bad the valves will wear an uneven surface in to the seat causing lower compression and you will get oil consumption.  Take a straight edge and line it up along the top of your valves, they should all be within +-.015".  Make sure to use a viton style seal and not an umbrella seal.  Oh yeah, don't forget to put your piston at TDC before taking the spring off.

Ps.  Where's my pilot bearing puller?

stupid question but whats blow by?

second stupid question;  if the valve guides are bad that means basically pulling the head and rebuilding it right?  might as well lap some valves while i'm at it

[JackstandJohnny]

think i answered stoopid question 1.  blow by is essentially oil in the air filter right?  there are trace amounts. barely noticeable.  i replaced the PCV valve that goes to the airbox anyways.  should i replace the back one?

[BlackYJ]

stupid question but whats blow by?

second stupid question;  if the valve guides are bad that means basically pulling the head and rebuilding it right?  might as well lap some valves while i'm at it

Seriously??  IDIOT 

[FiEND]

give nathan $50 and he'll teach you what blow by is

[XJHERO]

give nathan $50 and he'll teach you what blow by is

i only show you my trics Al

maybe it needs sum belt dressing

what no one eles said it YET

[bae146]

Dont you guys know all these problems are caused by lack of zinc?  Take some picks and post em, if you dont mind....