Chrysler Repair: 1988 Chrysler New Yorker 3.0 - Oil in the vacuum line, chrysler new yorker, vacuum line

Question
The car was running rough and died a lot. The first code showed a bad MAP Sensor. I replaced it and the issue appeared to be resolved, but it happened again. The new codes indicated that pressure to the MAP Sensor wasn't changing. I removed the vacuum line going to the MAP Sensor and the vehicle didn't die. The vacuum line had oil in it. I cleaned the vacuum line, the code cleared, and the car ran well for a while. After driving it for a week, the same thing happened. When I clean out that vacuum line, it will run well for a week or so. The MAP Sensor is mounted on the strut tower. This vehicle only has 44000 original miles on it. It has had a full tune up, had regular oil changes, and the PCV valve was replaced. I have no idea what is causing this and would greatly appreciate a solution. Thanks!

Answer
Hi Tim,
How is the oil consumption of the engine (miles/qt)? The main concern I have heard about the early years (before the  90's) of the 3.0L engine is that the valve guides wore out prematurely leading to excess oil losses which of course can cause oil that gets into the combustion chamber to recirculate via the egr system that then gets all over the intake system including the vacuum lines (at least that is how I picture that consequence). So that may be the source of the oil you are finding. Do you get blue exhaust smoke after a deceleration and then when re-opening the throttle? If you replace the valve guides with redesigned ones it is said to solve that problem. In the meantime, I would check all the hoses involved in the pcv system in case one of them is clogged up. Checking the rest of the vacuum lines might also be worthwhile because there is no reason to believe that the MAP line is the only one affected. If there is an underhood sticker, just use that as a road map for the effort. Perhaps the functioning of the PCV system can be improved and thus reduce the build-up in system.
Unfortunately it may require the heads to come off to do the valve guides, but you can verify that with a machine shop. Maybe the time to do it is when a head gasket goes or the timing belt needs replacement thought the latter doesn't require removing the heads. This is all I can offer which is based on what I have heard from other owners of the early 3.0L, though your problem with oil in the MAP line is a new one.
Roland