84 D150 318 smoking issues
 

I recently purchased an 84 D150 318 2bbl that runs strong, idles smooth, has good oil pressure but smokes at start up and a little under acceleration from a dead stop. (blueish oil burning smoke)I am thinking the valve seals are dried and worn since this is a realtively high mileage motor and has been sitting for many years. I was also thinking possibly the intake manifold gasket? but i am a bit reluctant to attempt to remove it since i must also remove the driver side smog pipe running to the exauhst manifold that is a bit shabby looking and if i break it i dont know where to get another one. I tend to think the smoking is a top end issue rather then a ring issue and does any one know where i could find these smog pipes or will i have to hunt salvage yards :confused:


Give me some thoughts !!!!

Welcome to the forum!

Your oil burning is probably the heads saying that they need to be rebuilt. For some reason the cylinder heads off of a 318 and 360 motors in trucks in the 80s seem to have seal problems. A friend of mine has rebuilt his share of cylinder heads for people with dodge trucks. I highly doult it is the intake leaking as that would effect the way the motor would idle and run.

As for the pipe, I would say look on e-bay and local junk/salvage yards. You may even get lucky with a local parts store being able to get it or having it on hand. Otherwise you will have to make one. Maybe out of copper.

The intake leaking is probalby not so and as for the heads, they may need to be done so this weekend i am gonna do the valve seals and see whats going on under the springs and take it from there.

I'd go with valve seals also.

3x on the valve seals

If you are going to do the seals, you might as well get everything cleaned in a hot tank if you can.

If you have never rebuilt heads or don't have the tools to do it, I would just take it to a local machine/engine shop. Some places like Robbins or Sanels have small machine shops in the back that can do that kind of work and usually only takes them a day or two to get it all done. Plus they usually don't cost that much unless you need valves. I had a set of AMC heads done and it only cost me $200 and they looked new when the guy was done with them.

I must be cheap, I leave the heads on the engine...lol:D

You need to do some diagnostic work to find out what the problem is. Is there spark to the plugs? Is there fuel? To check if it jumped time you will need to rotate the engine until TDC on the compression stroke and then see if the distributor rotor is pointing to the spark plug wire tower on the cap.

With it smoking on acceleration I would suspect the rings Usually valve seals burn oil when decelerating, high vacuum conditions where it will suck the oil past the seals.
Another possibility would be the rings are gummed up from sitting ? May help to run some cleaner in the oil.
Either way a high mileage motor needs new valve seals