Hi all, there may be trouble in paradise. On the 1977 F-150 with the 460 I've got a dead cylinder. What I mean is plenty of fire but fouling the rear passenger plug. Looks like a small amount of oil and I hav'nt had a chance to do a compression test although I ran a vacuum gauge off the intake and had a steady 20# at idle. Rev it up and the needle stayed very steady.I believe because the truck sat 2 years it may be a stuck ring or at least I hope so.The old guys always said to run a quart of trans fluid in the crankcase and I've also heard run brake fluid or Marvel Mystery in the oil. Any and all ideas will be greatly appreciated.Don't have the money or time for a rebuild right now.Also the truck levels out at about 1500 to 2000 r.p.m. and no blue smoke. Thanks again.

 

Since the truck sat for so long one cylinder may have rusted. This rust may clear out after a while. It may also have broken a ring from sticking in the rust. It will probably run a long time like it is because it is a Ford!

Otherwise you can try this trick to free a stuck ring.

Try making your truck into a mosquito fogger. This can upset the neighbors tho.

Pull a vacuum line that leads directly into the carb unless the dead cylinder is downstream from another easy access vacuum line. Put an extra length of line on and dump it down into a bottle of transmission fluid. Start the engine and the vacuum will pull transmission fluid into the engine. If you can't find a suitable vac line just pour a thin dribble thru the carb.

The transmission fluid will act as a top lube and will also lube the rings etc. It will put out extreme volumes of white smoke. It will also show every exhaust leak in your system. When you have run it like this for a few minutes shut the engine down and reconnect the vac lines. Pull the plug on the bad cylinder and pour another couple of tablespoons of tranny fluid in that cylinder, replace plug. Let the truck sit for 24 hours if you can, then start it up and be prepared for another 10 minutes or so of white smoke before it clears.

Good luck!

[link:www.ford-trucks.com/guidelines.html|FTE Moderator]
over!

 

[updated:LAST EDITED ON 11-May-02 AT 08:58 PM (EST)]My truck was same way,drove for years on other 7 plugs replaced #4 every 500 miles or less.Had broken compression rings in that cylinder.Nothing in a can will fix that.Almost replaced rings in that cly & put it back together but rebuilt it while out(88,000 miles).Try what Torque 1st says,it worked great on a mower I bought once.Brian

 

One more thing a Smokey cylinder can be, is the little rubber Valve stem seal on either the Intake or exhaust valve.
That can be replaced kinda easy. I got a tool from AutoZone, and the seals and I did all eight cylinders on my 460 in a few hours.

 

Skeeze,
You need to do a compression check. Until then every thing will be speculation. A bad valve seal/guide/seat could give similiar symptoms. I would soak the cylinder in marvel mystery oil for a week. Then start up the motor.
Don't put auto tranny fluid in a motor that burns oil! The combustion gasses escaping past the compression rings will burn the high detergent fluid and create and carbon powder that can seize a piston.
If this makes no difference, then pull the motor.
KingFisher

 

I have heard of that carboning happening when tranny fluid was mixed with the engine oil.

If I want to clean out an engine from the crankcase side I have had good luck with Rislone on several occasions. I have never used the Marvel Mystery oil but many people swear by it. I have also used a couple of quarts of diesel fuel or kerosene in a warm engine and let it idle a while and a little faster under no load to splash it around good b4 I drained the oil. This will not clean out heavy deposits and also runs the risk of breaking junk loose and spinning a bearing or seizing a pump. Even if you change brands of oil that can happen :-(

Good luck with the rings, but as it has been noted, it may get better and it may also run for years. It's a Ford!


[link:www.ford-trucks.com/guidelines.html|FTE Moderator]
over!