Actually after more reading it should say how critical is the changeover valve? I have no idea how to adjust boost and since lots of folks talk about but it doesn't seem taht anyone has explained it... Unless I missed something.
Anyway here is my original message.

I have read and read but there seem to be conflicting opinions as to how critical the overboost protection might be in these older turbos.
Some appear to be saying that with worn wastegate spring and other factors that the turbo probably can't make enough to hurt the motor but on the other hand I have read where these turbos can make up to 40 psi in manifold pressure which is not good.

The reason I ask is that when I first got this car it screamed in the 0-70 range. After doing some work, valve adjust (all were so tight you couldn't insert a feeler gauge), timing, and fuse replacement the car started running like a pig. I mean in the top end it felt like a naturally aspirated 300D.
This lack of power has been driving me mad for the last couple of days. Can you imagine? You adjust things the way they should be and it runs worse...
Anyway...
I went out for a road test this morning and just out of curiousity pulled the plug on the overboost switch on the firewall (actually the changeover valve) and low and behold the car took off!!!

Now I am not one to want to blow this motor as it only has 159K on the clock but then again I don't want to drive a pig either.

The PO should not own a car. This thing was destined for the scrap heap but I am trying to resurrect it.

__________________
'99 S420 - Mommies
'72 280SE 4.5 - looking to breathe life into it
'84 300SD Grey - Sold
'85 300SD Silver - Sold
'78 Ski Nautique