The Stovebolt Site Forums The Shop Area Engine Shop Diagnostics Help Needed

This is a 53 1/2 ton, all original. The 216 engine has always smoked some on startup and burns oil. After a couple hundred miles, the #6 plug fouls but all the other plugs are nice and clean and look good. Recently I installed Fenton headers. Now the blue smoke comes only from the right exhaust pipe. Also, a fine spray of dirty oil or oil and gas comes out of the right exhaust on startup and at idle. When the engine is cold, it occasionally backfires from the exhaust...not big bangs, just several small pops, like maybe raw gas is collecting in the pipe and igniting.
Oil pressure at the dash gauge is normal for these engines. I don't have a compression gauge, but I used a vacuum gauge and the vacuum seems steady at around 20, and the other vacuum tests don't seem to show anything wrong. It looks like the #6 cylinder has a problem. Could it be that the valves are sticking, or maybe the valve seals are shot and oil is leaking into the combustion chamber, and burning, and the gas isn't completely burned on ignition? What should I check? Thanks

Nothing is as easy as it looks!

If it doesn't bother you, drive it. If it does, you'll have to pull the head to see what's going on. While you have it out you'll probably want to have it done. That will lead to other things and other things will beget more other things and the next thing you know, you'll be doing a total rebuild and will have spent thousands of dollars to simply find out what was wrong with #6.

Spark plugs and oil can be inexpensive when compared to a full rebuild. Doing only the head is like getting to first base on a hit and then having the game cancelled for rain. It was good initially, but in the long run you'll wish you had run all the way to home plate.

You could luck out and just replace the head gasket, but after reading this page for years, I doubt that's the problem. Read the post linked below about Tony's hell to find out how small things somehow just keep growing when you start tinkering.

Horror Story Part 1
Horror story Part 2
Horror story Part 3

OK, for what it is woth.--- What you are discribing is - a bad valve guide and/or a bad valve seal. The valve seat on #6 intake is probably just a little bad also. There is an easy way to remedy this. Remove your head and replace "all" valve seals but "do not" do a valve grind. Chaeck and see how all valves and valve seats look, if they appear pitted or carboned use a little valve grinding compound and a hand( a wooden handle with a suction cuo on both ends) valve grinder and smooth them out just a little, make sure you do this valve grinding primarily on #6 (as this is where the problem has been). Re-esemble and you are good to go again without big problems later on. Do not do a total valve grind unless you want to do a total rebuild, it increases the pressure on the rings and bearings to much in an old motor. If you don't fix this problem it will only get worse for you and your engine. The oil you are burning is because of the poor valve guide. The popping is because #6 intake is probably fouled and allowing gas to "after-fire" in the chamber. If you need more infomation on this please ask.

Do you get excessive blow-by from the road-draft tube or the oil-fill cap?

My guess would be the same as Oly. I would add a can of Restore engine treatment and see if it slows down your oil burning. It usually works good on valve seals.

Also, what weight oil are you using? When I first had a 216 I ended up using 20W-50, it leaked a lot less oil.

Thanks for the ideas so far, guys. I don't see any blowback from the oil filler cap, and the road draft tube puts out a little light smoke, but nothing real heavy, at least at idle. I use straight 30w, non-detergent, and go through a quart about every 200 miles, plus a sparkplug. Agree with the advice that it may be easier to put up with it that try to fix, but I also read somewhere that replacing a valve seal isn't all that difficult. I'll try the Restore first.

sounds like the guys are correct in that you have a bad valve guide and or seal.You can get what is called a non-fouler for your spark-plugs.It is like a spacer/extender that keeps the plug away from the oil and not allowing it to foul for a longer time.You will eventually need to pull the head and deal with the problem,but I would run it for now if it doesn`t smoke too excessively.