FasterThanU87

Merc 502 multi port its an 04' an it goes through a half court of oil for every 30gallons of gas i run through. any ideas?

stevesxm

in an effort to make power , the 502's were built with oil rings with very light tension. they made a lot less friction but, in my opinion, those gains were offset by the amount of oil that ended up in the combustion chamber. fix the problem by calling total seal and getting a set of their replacement rings for that motor. the compression rings are file fit and work very very well and the oil rings solve the problem.

jwurl

I had the same problem with my 502 all last season. I was running 30w castrol GTX oil.. I switched to 40W Rotella this year and only had to add 1/4 quart so far this season. I found out it was an oil problem, not an engine problem. Jeff Wurl

Griff

I run Mobil 1 15-50 in my 520mpi's and now uses less than half of what it did with conventional oil. I use a quart about 12-15 hrs.

stevesxm

so thats a quart every 5 or 600 miles give or take. you figure thats acceptable ?. if you put good rings in it the performance would improve and the oil consumption issue will vanish.

mookymonkey

my 502 does the same. from my understanding the motors were built by merc to run alittle loose and wet which in my personal opinion is fine by me. i have talked to numerous people on this exact subject. no big deal to add oil now and then. i change my oil every 15 hours or so also for insurance and peace of mind. mark

stevesxm

the amount of oil you buy isn't the problem. its the amount of oil you put in the combustion chambers. there is absolutely no upside at all to burning oil. it kills the power, it mucks up the combustion chambers and leaves them prone to detonation, it leaves deposits on the plugs, it ultimately glazes the bores with all those attendent problems.

its not the extra 30 bucks a month... its the fact that the bore sealing is bad and you are suggesting that thats ok because all you have to do is keep the oil level up.

thats like saying " yeah the motor runs 220 degree water temp but i always get to where i'm going before it seizes up so i don't care. "

Griff

If its not broke, don't fix it. It is certainly not worth pulling the engines to replace oil rings when everything else is fine.
My 8100 Vortec in my truck uses a qt of oil every 2500-3000miles and always has since new and it doesn't run at 3000-5000rpms 80% of the time. It has 135k and is doing just fine.

FasterThanU87

thanks for all the ideas so far guys, i think i'm gonna try thicker oil for just this summer an do the rings in winter in my down time because like mentioned above when you burn the oil its still leaving some residue in the cyclinders and elsewhere.

FasterThanU87

hmmm so i bet if i used a synthetic it would burn a little more oil than usual also right? what about like valvoline 40w an just let it warm up before i take it out?