Will a specific weight oil MIGHT help cut down blow-by?

[Jon K]

NT, i switched to regular non-synthetic oil, 5w30, and im burning this **** off real bad. every like 300 miles im getting an engine oil low dinger.

[Bill R.]

high enough where your at a straight 40 weight might reduce some consumption, otherwise i'd run a 20w50, When running dino oils i always seem to notice the least consumption with castrol or valvoline on heavily worn engines and the most consumption with pennzoil. But if your using that much oil then probably none of these are going to help much, and if its bad valve guides causing it then you may find that you kill the cat converter pretty soon too. Bmw's recommended limit is about 800 miles to a quart, usually if you consume more than that there's a problem.









NT, i switched to regular non-synthetic oil, 5w30, and im burning this **** off real bad. every like 300 miles im getting an engine oil low dinger.

[Dave M]

Jon, have you done the regular investigating? The reason I ask is that I had similar oil consumption in my M50 and found one cylinder periodically soaking its plug. Thought it might have been seals/guides but it never smoked at start up and the same cylinder failed the wet compression test. Oh yeah, the car also periodically visibly burned oil after decending long hills in gear at high RPM (vacuum conditions). I'm having a rebuilt bottom end shipped next week for a project for next winter. The original bottom end has 500,000km on it and I'm guessing maybe a busted ring. Oh yeah, I tried 20/50 etc. and still burn quite a bit. Car runs like a top though.

Anyhow,

I'm interested in what you end up finding, keep us posted,

Good Luck,

Dave M

[632 Regal]

Jon try the 15w50 Mobil1, just make sure you dont drive hard at all until the engine is completely warmed up.

[632 Regal]

Jon, now that I just realized that you are running a Boost setup you almost have to run the 15w50 M1. In the racecar I could squeek by with the thin stuff but still had a TON of blowby, not the burn oil kind but the blow the breathers off the valve cover thing, that is naturally asperated not boosted or Nos. Im sure if it was driveable it would have used some oil though. With boost you definetly want the thick stuff for more protection from the heat the pistons are generating....

something like that.

[Jon K]

Confused: Winfred says 0w40, is that a thicker engine oil? Jeff says 15w50. Its my impression that these oils are far apart on the weight table. I think I want less-thin oil to keep it from going past piston rings. so is 0w40 thicker than 15w50??

thanks guys I really suspect a piston ring is letting blow by. Can I use a catch can and drain back to oil pan or no?

[ryan roopnarine]

Confused: Winfred says 0w40, is that a thicker engine oil? Jeff says 15w50. Its my impression that these oils are far apart on the weight table. I think I want less-thin oil to keep it from going past piston rings. so is 0w40 thicker than 15w50??

thanks guys I really suspect a piston ring is letting blow by. Can I use a catch can and drain back to oil pan or no?

if the products you mention above are mobil 1, that 15w50 is kinematically more like an extremely fat 15w40 and ow40 is a borderline 30/40 weight. is there any reason you don't want to use a very fat oil like the 20w50 dino bill suggested? i know i certainly wouldn't like to see mobil 1 evaporate that fast in my car. was going to pipe in earlier until i heard how much you were losing. was going to suggest german castrol syntec 0w30. was using m1 5w30 (ignorance) before, consumption was about 1.1 qt/6000 miles. if my valve cover was still healthy, i got .6-.7 quart per 6000 miles on the german castol, which is k'matically about 40 weight.

[632 Regal]

bigger numbers means thicker. The first number is the oils flow rating at a cold temperature and the second number is how thick it is rated when hot. There's just too much information to learn on oil so to keep it simple bigger number=thicker.

[Jon K]

bigger numbers means thicker. The first number is the oils flow rating at a cold temperature and the second number is how thick it is rated when hot. There's just too much information to learn on oil so to keep it simple bigger number=thicker.


Would the 20w50 or whatever, the fat oil, would that cause issues in my supercharger? The supercharger takes standard oil, no special gear lube.

[632 Regal]

Unless the supercharger manufacturer specifies a certain oil weight range I would personally stick to the M1 15w50 with your setup. I dino might help with something as mentioned but in using a supercharger I would absolutly stick with synthetic. The days of pistons and rods on the ground comes into vision when I see that word "dino" oil.

[TheDuke]

There is a really good article in May issue of Import Tuner about engine oils. It doesn't explain it all, but it touches most widely asked questions about motor and tranny oils.

[632 Regal]

There is a really good article in May issue of Import Tuner about engine oils. It doesn't explain it all, but it touches most widely asked questions about motor and tranny oils..