I have oil-fouled plugs. Does the engine need a valve job?

I am assuming it is oil fouled rather than fuel fouled. Oil fouling is usually due to valve stem seal leakage. Most engines have the oil return on the cylinder head at the rear. When the engine is shut off, some oil pools at the rear of the head. If the valve guide seals are worn, then the oil will leak around the stem of the #4 valve and eventually foul the plug. If there are no real issues with the engine other than this one, it is usually best to keep a clean plug or two available and swap out the plug periodically when fouling is detected. Then clean the fouled one and keep for reuse later. If it is happening too often, getting the cylinder head reconditioned is a good idea.

What you are probably experiencing is oil fouling of the plug due to valve stem seal wear. GM engines drain oil from the heads at the rear of the engine, so the #3 and #6 cylinders are most prone to this problem as oil will pool there on its return to the oil pan. The only solution is to replace the valve stem seals, but, knowing this is not a serious issue unless the oil fouling is excessive, you can simply clean the plug or swap it out periodically until engine rebuild is warranted.

Wow.. 1967 ... 427.. I would start by checking the dist cap and spark plug wires and coil. .. this is such a valuable car you want to go first class on parts.. Performance cap rotor, plug wires like accell or better.. Bascially give it a good tune up..it is a carb car check the level of the flotes in the carbs. excess gas could be fouling the plugs.. Valve seals is a good place to look for oil comsumption.. If it is the Valve stem seals.. it will smoke when you first start it after sitting overnight or over day/.. during the night oil runs down the valve stem and collects on the top of the piston.. Last one these i rebuilt the machine shop installed the wrong cam bearings and the oil did not make up to the valve train.. had to pull motor and dissemble and replace the cam bearings with the correct ones.. seems like sometime during the year Chev, changed the location of the oil feed holes for the cam.

Usually one of 2 causes. Most common is a bad valve stem oil seal allowing the oil past the valve stem when the engine is shut off.Second is a broken or bad oil ring on that piston. Be blessed.

This is likely your spark plug tube seals. They come with valve cover gaskets because you will need to replace both in a job. You should also probably replace the spark plugs themselves, as the ends are probably fouled.

If you are interested in doing this job yourself, I would suggest going down to your auto parts store of choice and purchasing a repair manual for your car. Haynes is the book of choice, typically. It will show you pictures of the valve cover being removed.

Was the plug fouled again after you made repairs? Did you install a new plug and run it? If the plug itself is fouling you probably also see blue smoke in the exhaust pipe. Get the engine warm, check compression and do what is called a cylinder leakage test, it puts a volume of air into each cylinder with the valves closed and how much air leaks out determines the over all health of the engine. Does the engine have excess oil consumption? The oil entering the cylinder and fouling the plug can enter from a worn valve guide or guide seal, a worn or damaged oil control piston ring or a worn or damaged piston bore or piston, none of which are going to be inexpensive to fix.

Good luck, i hope this helps.

Oil is getting into the combustion chamber and fouling your plugs. The overall problem is that the engine is 20 years old, specific problem is that you need a ring job and/or a valve job to keep the oil out of the combustion chamber. Check for a price on a rebuilt engine exchange, if not available or too expensive then you need to find a junkyard which has old Isuzus and find a similar engine with much lower mileage and swap it in. Either situation means you are going to spend more money than the vehcile is worth to fix it so you might just want to scrap it and find one about 5 years newer.

There is a PCV valve, but it does not keep oil from the plugs. The oil rings on the pistons do that. You will need to rebuild your engine if you are getting that much oil on the plugs. :-(

Blue smoke is never a good thing....

Blue smoke is caused by engine oil entering the cylinder area and being burned along with the fuel air mixture. As with the white smoke, just a small drop of oil leaking into the cylinder can produce blue smoke out the tailpipe. Blue smoke is more likely in older or higher mileage vehicles than newer cars with fewer miles.
How did the engine oil get inside the cylinder in the first place? The car has many seals, gaskets, and O-rings that are designed to keep the engine oil from entering the cylinder, and one of them has failed. If too much oil leaks into the cylinder and fouls the spark plug, it will cause a misfire (engine miss) in that cylinder, and the spark plug will have to be replaced or cleaned of the oil. Using thicker weight engine oil or an oil additive designed to reduce oil leaks might help reduce the amount of oil leaking into the cylinder.

your engine has worn valve guides, piston rings An engine that burns a lot of oil (more than a quart in 500 miles) is an engine that needs to be overhauled. Normal oil consumption should be a quart or less in 1500 miles. Most newer engines consume less than half a quart of oil between oil changes (every 3000 miles). So if your engine is burning oil, it's essentially worn out and needs to be repaired.
Because the cost of overhauling or replacing an engine often exceeds the value of an older car or truck, many people will just keep on driving a "mosquito fogger" in spite of the blue clouds of smoke it leaves behind. Never mind the pollution it causes, oil is cheaper than a new or rebuilt engine they reason. That philosophy may be okay if you live out in the sticks somewhere. But in urban areas that require periodic vehicle emissions testing, an engine that's burning oil usually won't pass the test because of excessive hydrocarbon (HC) emissions. You may get by on a waiver after you've spent some money (in vain) on a tune-up, but the fact remains you're still a polluter.
An engine that burns a lot of oil will also eventually foul the spark plugs. Thick, black oily deposits build up on the plugs until they cease to fire. Then the engine misfires and loses power. Cleaning or changing the plugs may temporarily solve the problem, but sooner or later they'll foul out again.
Forget about "miracle" oil additives or pills that claim to stop oil burning. They don't. Better to save your money and put it towards a valve job and new set of rings.

Valve guide/seal, Piston rings, head gasket. Getting oil fouling on plug?