Talking about an 86 420SEL with 203k miles.

Another problem I am having is with the transmission. Long story short it worked fine before the car was stolen. I suspect some awfully hard driving when in the hands of the perp.

So now I have a tranny that seems to work reasonably well about 70% of the time and only when easy on the gas pedal. During its good times I can sometimes feel a little slipping in 2nd (main start up gear) and it will occasionally stutter when it shifts into 3rd.

The other 30% of the time it feels like it is slipping quite a bit in 2nd and will hold second for an extended rev range before searching for 3rd.

Now if you get agressive at a light it slides into 1st like a champ, gives you a good case of whiplash, slides into second like a champ and stays there for the next 3-5 miles. It won't go back into 1st or climb higher than 2nd. If, instead, you romp on it once you're going fast enough (20 mph) to not drop into 1st it works just fine and doesn't seem to slip or hesitate shifting.

The other oddball is that when it is acting up if you turn off the car and then restart it usually calms down and cooperates. I'm also wondering about a possible vacuum leak as it seems to idle around 850 rpm and I'm sure it was idling at about 600 before.


So the first and most expensive question is: Am I looking at a new tranny? If we can answer "No" (oh please do) to that one then the next logical question is: What am I looking at to fix it. I have read about the B2 piston problems but I think that is for the diesel variety and the description doesn't cover all aspects of my scenario.

At this time I am continuing to drive it and trying to catch it when it slips and ease off. My gut says new tranny but I can't believe how well it works at times. Just like the old days. I'm sinking all sorts of money into this car after the theft, much more than the car is worth, but I love this tank.

Thanks folks for all your wisdom and willingness to share.

I was having similar problems with my 380SE. I had visions of expensive repairs, but it was just low fluid.

I have had similar problems with my 300SD. Low fluid was the problem; solved everything. Hope this is your problem.