In October I took a chance on a basket case 1996 Bronco for $850. The PO had just put 4 new Michelin MTXs on it so I figure I only paid $250 for the truck . I had set aside $2500 to go shopping so even if it had lunched something expensive I'd still have been mostly inside my budget. It had many, many issues but one of the minor ones was oil consumption.

It had 190K on the 351 and lost about 1qt of oil per 1k miles. I changed it over to Rotella 10w30 and kept it fed for the first 5k interval. At 195k I decided to spike the Rotella with 1qt of MMO. I've used MMO as a general purpose lube and a fuel system cleaner before but never in the crankcase. Again, since this was a beater that I didn't have much hope for anyway I'd give it a shot. Well, I'm almost to the 200k mark for the next oil change and the consumption has gone down to almost nothing. I haven't had to add any oil in the last 2k. The combination of the diesel add-pack in the Rotella and the solvents in the MMO have cleaned up the rear main so that I'm not seeing drips there anymore. The oil itself doesn't look that bad so there must not be that much sludge, just a lot of varnish but I won't know for sure until I get the filter cut open.

The moral of the story? Good oil changed regularly can work "miracles". Who knew?

 

Dunno what is/was in MMO, but it was a standard treatment for intermittent (lightly) sticking exhaust valves on Ironhead Harley Sportsters and worked well on a couple of them I observed. It's a fair penetrant which may have something to do with that.

 

seen it work miracles with sbc's sbd's and sbm's with sticky valves...... good stuff granted changing the oil with a good oil bfore **** starts stickig helps :P

 

I too am a fan of Marvel Mystery Oil. I don't use it all the time, but feel is a very useful product for the cost. I've also had a mechanic tell me using the smaller container of MMO every month also helps modern vehicles that have the fuel pump in or near the gas tank. It provides lubrication when mixed with gasoline. Also, gasoline itself is a "coolant" for fuel pumps and you should always run a modern car or truck with at least 1/2 tank of fuel for proper pump cooling. People who consistently run their vehicles at or near empty all the time, or consider a "fill up" :>) to add gasoline which takes the level in the tank to the 1/4 mark, run an unnecessary risk of burning up a fuel pump. They run much hotter than normal = premature failure.
Marvel Mystery Oil and keeping your tank at least a 1/2 tank full all the time, or more, is one of the best things you can do for your fuel system.
Plus, truckers also say MMO helps to prevent diesel fuel from gelling when temps are at zero degrees or lower in winter conditions.

 

Just going from whatever was being used to Rotella T 5W-40 stopped all my oil consumption. This is no exaggeration. I don't know what was being used in it when I got it at 109k miles, but it's almost to 130k miles now, and has had Rotella T Synthetic 5W-40 ran in it for the majority of the time, with Castrol GTX 10W-30 being the first couple of oil changes. It used to consume oil. No smoking or anything, just used a little, well, a quart every 1500-2000. Over the last 2 oil changes, it hasn't used a drop. I'm at 2500 miles on this oil change and it's exactly where I filled it to.

I'm surprised to say the least. I guess it's the oil cleaning up and maybe helping the seals at the same time. Who knows, maybe in another 10k miles, my rear main will start leaking like a waterfall. Time will tell.