sitting engines, rust on valvetrain?!?
 

I have a 1989 5.5L M117 and a 1976 OM616 sitting in my shop and I decided to look in the valve covers tonight and what did I see?

Rust!

on the M117 I saw it on the top of a cam lobe and the OM616 I saw it on the part of the cam between the lobes

is this normal?

what should I be doing to deal with this?

lots and lots of WD40. and keep them cleaned.

how did this happen?

this engine was perfect when I pulled it from my 560 last year

How long have they been sitting? The oil will dry off any engine is it sits long enough.

Did the cars come in out of the cold into a nice warm (and perhaps humid) shop? This could be a condensation problem.

they have been sitting for about 6 months,

they came from hot to a non climate controlled shop, now its super cold and winter time.

seconded. you always have to keep the parts lubricated. what you might try is fogging the engines. its a marine term. an additive in the fuel produces a "fog" of oil that coats every part of the engine. its used for putting boats away for the winter.

neither engine is connected to anything to make it run, how might I do that?

Given your circumstances, I would take a small brush and paint grease on the cam, it's not for real lube but for protection. Open the plug holes and glow plug holes and squirt a fair amount of oil in the cylinders.

I have a friend who has some very expernsive engines and he just fills the crankcase to the top with 30W oil after he has put oil in the cylinders, painted the cam and replaced the valve cover. He's toyiong with hooking a small pressure pump to one of the oil lines to pump grease everywhere. But he takes them 100% apart when he works on them, so he's not typical. Plus he has space and MONEY.

alrighty, I havent pulled the valvecovers to know if all the lobes have this on them, but I would like to hope they arent

I'll make sure to put oil in the cylinders, they both currently have full sumps

I'm not sure if this is what strelnik suggested, but I've heard of some people prepping the engines for storage by filling the engine with oil until it can take no more. This would immerse the valvetrain in oil.

Seems odd.....we've had one of our diesels sit for 4-5 months before and there was still oil on the cams when we took off the valve cover.....we run it with synthetic. No rust at all.

yep, as long as the valve cover doesn't leak

Also realize that cast iron is more prone to rust than steel.

I might try using assembly grease on the parts - what you would use on a freshly assembled engine (or new cam, etc). There are varying opinions on whether or not you should change the oil within 500 miles of doing this...

But what should he do about it?

Should he remove the cam and carefully clean the affected lobes with x-fine steel wool and oil? Maybe try something like stainless steel polish or naval jelly to dissolve the rust, or just oil it and turn the motor and let it sort itself out?
Would he risk compromising the hardened/polished surface if he tried to clean it?

When I did my head gasket I sprayed the cam w/ WD-40, wrapped it in paper and the put it a couple socks and it still got some areas of fine rust which I lightly went over with x-fine wool and oil. But it was very light and easily wiped right off. If the rust is bad enough that it shows any visible pitting at all I'd be leery about using the cam (or the rockers if they're the same).

Any rust on the lobes usually clears up after a few seconds of running.

if I use a engine building grease on the lobes that have surface rust and pre-oil the valve train and pistons for a few days, will that damage the engine?

the diesel looks better than the gas engine from what I observed, these won't have a chance to run for another 4 months so I am a little worried

would hate to have to buy new engines since these were both top notch plants less than 6 mos ago

I agree that the rust will burnish away during use. It's really a judgement call as to how much rust and pitting can be tolerated.

Well, the problem is, "surface" rust doesn't grow on the surface, it is oxygen that combined with metal, is porous and occupies more space, and therefore sticks above the original surface of the metal over what is a pit. This is the way it is on a magnified level. The question is, will the oil film remain intact over the pits, and is there enough "high metal" between the pits to carry the load, until such time as the whole thing evens out from wear? only a "line" along the cam is actually in contact with the cam follower at any given moment during operation, and the pounds per square inch along that line are spectacular. The oil film sort of "floats" the cam on the cam follower. If the metal was actually touching, it wouldn't last, no matter what kind of metal it was.

IMO, lube it well (even with assembly lube), run it, look at it in a hundred miles, and if it's OK, forget about it. If not, there was nothing you could have done to "fix" it after it happened.

thanks for the advice :)

is there anything I should be doing now to stop it in its tracks for the 4 or 5 months till I can get an opportunity to get these fired up again?

I see a number of options, depending on how much trouble you want to go through and what is available to you.

- fill the cylinders and engine with oil as discussed above.
- remove the valve covers and slather the parts with grease, oil, or Fluid Film. Or better yet, use Safecoat if you can get your hands on it, which is specifically made to prevent rust on parts that are later lubed.
- place the engines in a humidity-controlled environment.
- bag the engine with dissicant.

Fog them with spray WD40
 

I have an open 240D sitting in my garage and they will rust. Cold at night and the garage being uninsulated can warm up nicely during the day allowing for a nice film of water to lay on that cold steel. I spray them down with WD40 once a month and keep them covered with oily rags and old towels. That will keep the warm air from the cold steel and stop moisture from forming. The WD40 is a second line of defense. I went out and re-oiled mine today.

more good advice :)

can I get Safecoat from any chain retailer or should I just order some online?

I could probably bag the engines but really cant get them into a climate controlled environment

I'll spray down the valvetrain with WD-40 and when I can, fill the cylinders with oil

Keep it shinny, no mess
 

You don't have to fill those cylinders with oil. Geepers, that would be a mess. Spray them good with WD40 and then stuff rags into the cylinders, spray it again over the rags and cover it up with a clean floor mat or old overcoat just to keep it from getting hit with warm air and to keep dirt and debris out of it also. Guaranteed to be bright and shinny in the spring, as bright and shinny as they were when you put it away.

how do I stuff rags in there if the engines are completely intact?

spark plug holes can't be that big?

Well, OK
 

I thought you had an open engine, heads off. If not, spray WD 40 into each cylinder and replace with a spark plug (glo plug). You won't get rust in a closed engine because there is really no air flowing through it. Put the valve cover on it and cover it up the best you can and try to keep the humidity down. Everytime you bring in a snow ice coverd car with a warm engine, you are adding some slight heat and humidity. Water dripping on the floor from the car is a big factor. It is this warmth and humidity floating around your very cold garage that causes the problem. So cover it up with old cloth, rags, carpets or throw carpets or old overcoats, but keep it covered.

the shop is sealed for the winter, so luckily it should be as controlled as I can hope for

I'll spray in WD-40

Wait until you get a warm balmy day during the winter. The warm humid air will hit the cold metal and cover everything with dew. This happens once in a while in my garage. When that happens, everything is wet... my cars, tools, fastener collection...

An old school trick for an engine that was going to sit for a while was to pour a quart or two of good old fashioned trans fluid down the throttle to coat the intake valves/pistons/rings and turning the the engine over manually a few times. In your case, I'd remove the valve covers and pour a bit over all the valve train parts as well. It'll stop the rust and prevent any new stuff from forming.

As has been stated earlier, any fine surface rust will dissappear quickly once the engine runs for a bit - much like the rust on a brake rotor. You'll probably want to change your oil after a few hundred miles though, as there will be very tiny rust particles circulating through your engine.

I hate that. Why is it some metal smells like puke when it oxidizes? I've been tossing in the little silica packets that come with stuff in my tool cabinet(s) drawers and that seems to help a little...