What does fogging the cylinders mean?

Rob -- It's taking out the spark plugs and spraying a little engine oil into the cylinder volume to lube the cylinder walls (and the finer the spray, the better -- hence "fogging") before doing some hand crankshaft rotations.

 

That MUST be a Brit term.

 

Well over here in Michigan I bought some "Fogging Oil" at my local auto parts store. Not sure if it was imported or not...

I'm actually just going to fill the cylinders of my long-dormant Suburban with oil & try to remember to pump it back out before I try to run it!

 

Are you sure you didn't buy it at a head shop?

 

I had been told fogging cylinders is something you do before an engine is put in storage or packed away for the winter. It was supposed to entail spraying oil into the intake(s) until the running engine stalls. This lubed the combustion chamber, the walls, the valve seats, etc. etc.

 

I spray fogging oil into my boat motor in the fall, before storing. Supposedly it protects from corrosion. As was mentioned earlier, just spray into the intake until the thing stalls. In the spring, you simply put in a clean spark plug, and off you go. I'd suspect that you'd do about the same for a car.

 

I just put in the plugs and went. It was a little smoky for a minute or so. Turning it over with the plugs out will get rid of some, but hopefully, it its done its job, most of the oil will be clinging to the cylinder walls.

 

fogging a cyl is common for engines that are stored for long periods. It mostly is used in smaller engines that are put away for the season like snowmobiles, jetskis, lawnmowers etc. Ill bet it would work for a car the same way. I wouldnt pay anyone to do it. take out all the plugs, get a good fogging oil from a motorcycle shop, spray each cyl, crank for 2-3 seconds and replace plugs. The key is the oil, use the wrong oil and you will only foul a bunch of plugs when its time to "defogg". Maybe marvel mystery oil or the like.

 

Marvel Mystery Oil is excellent for this...Mercury Racing also makes a special product for the big outboards.

 

I'd be careful about "1 size fits all" here -- i.e., introducing an oil into a carburettor is OKish (where it will get washed off downstream fairly quickly by the fuel when you bring it back to life), but I wouldn't put any oil into a port-injected intake system (e.g. a K/KE-Jet).

 

I think it is even less well advised to do it to anything with MAF's. And don't forget if you are putting in enough to make the motor die, consider what is being done to the cats.

 

We use to "fog" boat engines as part of a winter storage service. We had an old spray paint gun with an 15" rubber hose jammed on the gun's outlet. We removed the spark plugs, put the hose in the spark plug hole and sprayed in the oil. A little fog came out of the carb and exhaust with the application in each cylinder. It always seemed to work well and there were never any "spring start up" problems.

 

I fog my jet ski's engines for winter storage, then in the spring, i will have a charged battery and start the engine with the old plugs and let them run for a minute or two, it will be blowing tons of smoke out the exhaust while the oil is cleared out of the cylinders. Then i replace the spark plugs with new ones and then off the the lake.... Or should i say in your terms, off cruising.... I would think that would be the same for a car too....

 

Not sure about fuel injection but for carbs you are supposed to spray it into the air intake with idle rpm at fast idle until it stalls...It will smoke up the whole "hood"....Then remove plugs and spray a small amount in the cylinder and crank over couple of times. Put rag over holes or it will just shoot out.
Put plugs back in and store..This stuff is a very sticky oil which will coat the internals and offer corrosion protection and still be there when you start in the spring..It is highly recommended and inexpensive. In the spring remove the plugs and crank the engine a few times..This is VERY important as any "foggin" oil left on piston tops will be compresssed and you can snap a rod...Then put plugs back in and start..Let run until smoke clears and then preferrably replace plugs with new ones.. 2 strokes are different...

 

http://www.yamaha-motor.com/accessories/apscitemdetail/3/122/349/All/1/detail.aspx

 

If fogging and not "de-fogging" be sure that the red plasctic tube thingy
doesn't go into the spark plug hole and drop in

 

Rob -- What model? On an injected car, I'd be equally worried about the fuel system. I don't think that you can really predict too much -- e.g., the "damage" could be very dependent on the atmospheric conditions (moisture condensation, salt content, etc.) during the storage period (and I'd guess it unlikely that a "perfect" car was parked for 12 years -- unless they just found it and the dead driver was still inside ). As a buyer, I'd assume the worst (total rebuild required) unless proved otherwise by the seller (i.e., at least bring the thing back to life enough so that a leakdown test could be done).