We live SW of Boston. My wife has a 90 300D that has had this problem for over a year now. At first it started when the car was cold and would only happen once or twice while warming up. Now it's pretty much constant at low speeds.

The car will bog down for a few seconds, then blow out a plume of blue smoke from the exhaust and then run normally. It may do this two or three times in succession. Occasionally it will just blow out smoke constantly for about 30 seconds but have no loss of power.

The car does not seem to be overly using oil. We have the oil changed every 3-5000 miles and do not have to add oil between changes. She has on occasion gone 8000 between changes and still has not had to add oil.

We took the car to Foreign Motors West in Natick, Mass and had a diagnostic ran. The results were:
-Cam Timing - Good
-Glow Plugs - Good
-Injection pump - off by 3 deg, (acceptible)
-Intake Manifold ports - good (small deposits)
-Valve seals - good
-Valve guides - good
-EGR - fuctioning and not clogged
-Compression - all between 22-23 bar

They offered to completely break down the engine and go through it piece by piece, but said that would cost at least $4000.

Right now it's not looking good for the 300D. My wife needs a car for commuting and if I can't get this one back on the road soon we will have to trade it in. So any help anyone could offer would be greatly appreciated.

Has anyone seen this issue before and knows a repair that doesn't run into the thousands?

Or does anyone know where we could buy a rebuilt engine for a 300D, and how much it would cost?

Thanks