Dear Ole Mechanic;
The other day I was driving to town in my old ranch truck to get feed, when the truck quit. It seemed to be running fine when I left the house, but after a few miles it seemed like it was struggling to get up the hills. Then it started slowing down even though I had my foot almost on the floor. When I pulled over and pushed in the clutch, the engine quit and would not crank over. When I opened the hood, it was like I had stuck my head in an oven. I let it cool while I looked things over and noticed a vacuum line off of the intake manifold. Then is when I also noticed a split in the upper radiator hose. Sure enough, the radiator was empty. I got a lift from a neighbor back to the house and got some water and duct tape. By the time I got back to the truck, the engine had cooled down, so I taped up the split hose, filled the radiator with water, and put the vacuum hose back on the fitting. I left the radiator cap loose, so the tape wouldn’t get blown off from the pressure in the radiator. The truck cranked over slow, but it did start, so I headed into town to get the feed and a radiator hose. A few more miles down the road was a stop sign at the highway. As I was shifting into second gear after getting on the highway, the truck started missing bad. When I looked into the rear view mirror I couldn’t see a thing for the cloud of smoke. I turned around and made it home, but it was missing and smoking all the way. The truck is a 1982 Ford pickup with a six-cylinder engine and a three-speed manual transmission. I know I got the engine too hot, but why is it missing, and why is it putting out all of that smoke?
North of Town Rancher
Dear North of Town;
Yep, you got it too hot. It almost sounds like you got the piston rings so hot that they lost their tension and are letting engine oil get past them and into the combustion chamber. Once there, the oil would try to burn and put a lot of smoke out the tail pipe. However, there is something else going on, too. With the vacuum hose off, there was some extra air getting into the fuel and air mixture in the intake manifold, and one or more cylinders was getting a mixture that was too lean. That could cause things to run hotter too. It was like a cutting torch--get things hot, add more air, and you can cut steel or melt aluminum. Combine that with an overheating engine, and I would bet that there is a hole in at least one--and maybe more--of the pistons.
How do you find out how bad things are? By running a compression check on all of the cylinders. A compression tester is like a tire pressure gauge. It will hold a pressure reading until you read it and reset it. A compression gauge can be purchased for less than $20 at most auto-parts stores or in the automotive department of most big chain stores like Wal-Mart or Tractor Supply. To use it, remove all of the spark plugs from the engine, and then check each cylinder one at a time. Hold or screw in the gauge in a spark plug hole and crank the engine over three times. Write down the gauge reading, zero the gauge, and check the other cylinders the same way--one at a time. All cylinders should read at least 100 psi, and they should all be within 10 psi of each other. Low readings of say 50 psi on all cylinders, probably mean that the rings have gotten way too hot, and the smoke is coming from the oil getting past the piston rings, causing smoke out of the tailpipe. I suspect what you will find is that one or more of the readings will be a lot lower--like 20 psi or less. That would tell you that there is a good sized hole somewhere. It could be a burned valve, but more than likely it is a hole in the piston.
Can it be saved? Maybe, if the block and head are not cracked from the overheating, but it is going to take an engine overhaul plus a bunch of new parts. That means expensive--in the $2,000 to $3,000 range. Finding a junkyard engine out of a wreck would be a little cheaper. Just do not get a later model fuel injected engine as the heads are NOT the same, and adapting the electronic fuel injection would be even more expensive than an engine rebuild--unless you do all of the computer wiring and adapting yourself.
My recommendation would be to go shopping for a new old ranch truck as the $2,000+ spent on an overhaul would probably find you a decent new old truck.
Herr Professor Nuzanbolts