Turbodiesel:

If you started using oil after the chain/tensioner change, check for leaks at the front cover and tensioner. Both are known for leaks.

A broken blowby tube is VERY common if you try to take it off -- broke mine the first week I had the car, so just put a bit of heater hose over the two ends. Will replace it when I do something else that requires removing the valve cover, and will replace the grommet at the same time -- rock hard.

Variable and unpredictable boost is most likely in the boost control circuit. Check it all for leaks first, and replace the ALDA if it leaks (you can swap the one off the parts car, at worst it will be out of adjustment a bit, no more). On the 603, it's not mechanically tied in, just pushes against an operating rod in the pump -- captive nut at the bottom, hold ALDA with a wrench and use another to unscrew the captive nut, remove, install the other.

Don't forget the wastegate controller hoses!

If the boost regulation system is good, the turbo is sticking. Usually worse cold, and eventually will stop altogether.

ANY binding of the turbo means the bearings are shot. You may or may not have play -- if the problem is coked oil in the bearings from not cooling it off properly after highway runs, you have NO clearance! Seals can go bad without the bearings going, too -- and until you are using considerable oil, no blue smoke!

Turbo rebuild will vary from $400 or so to $750 or so at a reputable diesel shop. New bearings/balance will be around $400, a cartridge will be $750. This will be with a years warrenty -- be prepared to change oil supply and drain lines.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!