Roy's Garage: '90 2.4-4G64 5-spd D-50

[royster]

BradMPH has provided a great information resource for valve guide seals HERE.

Oil consumption is discussed HERE.

And thillskier testifies HERE about oil consumption/smoking eliminated by replacing valve guide seals.

As so many of our problems seem to be from engines smoking heavily...many of them are up to a pack-and-a-half a day ...it has been my observation that 85% of the problems can be traced to worn valve guide seals. That is definitely the case with my 2.4.

I also discovered two valve guides have slipped out of place, and in the worst location: #4 and 3 exhaust, which are at the back of the engine in the area oil gathers most when the engine is shut off. These guides slipping down caused the valve seals to dislodge and become useless. The symptom was extreme engine smoking at cold start-up. Once the engine was warmed, the smoking was minimal: an occassional cigar at worst.

If your truck is smoking, and a nicotine patch isn't working, look into replacing the valve guide seals before you panic about an expensive rebuild. They CAN be replaced while the head is still on the engine, though caution must be taken to assure valves don't slip into the cylinder when the keepers and springs are removed. The Chilton manual suggests setting the cylinder you're working on to be set at just-before TDC, the spark plug removed, and the cylinder stuffed with nylon rope. Once rope is stuffed as much as you can, turn the engine gently to TDC. The rope will support the valve while you replace the guides. After each cylder is serviced, back the engine to just-before TDC and remove the rope. (See the book or ask here if this suggestion isn't clear).