More smoke on startup with 10w30?

I got a lot of smoke on start-up with my BB512i when I tried Mobile1 5w50. When I went back to Castrol TWS 10w60, the start-up smoke went away...

 

A little oil seeps past the valve guides/stem seals and pools. This is to keep them lubricated (at least on my car; I'm assuming yours is the same). The lower the viscosity, the more will slide by and the more smoke you'll see on start up.

I would think lubricated valve guides is a good thing to fight wear on startup; when they're TOO worn, it will smoke on acceleration as well.

It's not a bug; it's a feature!

Ken

 

I once was given a Honda Civic for free because of what it did when you started it. It would start smoking a few seconds after it started, and would pour out thick clouds of smoke, that would litterally engulf the entire car so thick you couldnt see anything. Half a minute later it would clear out and run fine all day, no more smoke. But start it up cold and it would repeat the process. I ran some Gunk Motor Flush through it and changed the oil and it never smoked again. I can only assume the rings were fouled in some way.

I had simular though not as dramatic experience with a high mileage 300E. That car had records from new, with me being second owner at 165K miles. The car had 7500 mile oil changes with 10W30 Pennzoil. Same trick and a lot of oil changes fixed that car too.

But most of these F cars have low mileages, are doted on with frequent oil changes, and the oil everyone is using is generally top shelf, no matter the brand.

More anecdotes? I owned a MB 300 diesel for a while. It wouldnt use a drop of oil in over 2000 miles. Yet by 2500 miles it would be down a quart. Change it and it was good for another 2000 miles, then instantly start burning off a quart in 300-400 miles. You could keep adding and driving, but the stuff kept burning off at the same rate until you changed it. Obviously something odd was happening at the molecular level, and I am sure the same thing is going on with these F cars smoking on different brands.

Could be different ring manufactures, different piston design or ring design, or a different surface finish on the cylinder. And those differences could be reacting in some odd way to different oil formulas. And beyond that, no one will ever know.

 

I've have very good "luck" with the Valvoline VR1 series.......I use their 10w30 in the 72'Vette, 20w50 in the Pantera, and did use the 40W in my HP boat motors when I had it. Never a failure and when i've sampled bearings the wear was fine.

Their VR1 also has a high zinc content thats great for the bearings. (I would also comment that even when an engine has sat for a while, lets say I've pulled a valve cover or oil pan, the components have all had a nice "slick" coating of oil on them....... just saying it didnt all drain down to the pan). After a regular drain, lets say 3000-4000max the oil still has a good feel to it. Some others I've tried, even after 1000 miles on a more demanding hot day, car events...etc, they seemed to thin out a tad.

I think the M1 or compatable......RedLine, RoyalPurple....etc are outstanding products but they also find every seal to come out of, or, around guides...etc.

 

I currently run Kendall GT1 20W-50 in my '79 308GT4. I changed the oil myself about a week into ownership with Mobil-1 0W-40... WAY too thin - oil pressure was not high enough when fully warm, and it leaked much more after the change (no leaks when I bought it...big drips after the M1 change). Now, the leaks have all but stopped, and my fully-warm oil pressure is much better.

Didn't have any smoking issues with the 0W-40, though...