I have a 1983 300SD and I think my turbo just went out. I was waiting at a fast food place and the engine was at idle. I heard a sound like my extra radiator fans came on but I was at 80c so that was not it. I didn't notice anything wrong going home, about 1 mile away. I got home and changed my diesel vacuum shut off valve that was giving me problems and my rear brakes and rotors. When I road tested I noticed the engine was sluggish, I can only get up to about 75 mph. and at that only very slowly. The only thing I can figure is that my turo went out. Any advice?

Sounds like you better recheck that vacuum shut-off valve. It is probably interfering with free rack movement. It might be as simple as loosening all the bolts and shaking the valve off the rack. It shouldn't touch except at shut-off.

Do you think I damaged anything? I already tighten down the vacuum valve.

No I don't think you damaged anything. I have also seen vacuum shut-off chambers that stick (they don't move freely because the guide binds on the arm that moves. If loosening (and retightening) the screws doesn't help then remove it and suck it fully short and see if it releases freely when the vacuum is released.

Thanks for your help, I'll try that today.

Well, don't I feel silly. I had knocked a vacuum line off a little vacuum/electrical switch on the firewall. I hooked it back up and all is fine.

Thank you very much for all your help Steve, I owe you one.

I'm learning, slowly. I've never owned a car with sooooo much vacuum.