W126, Accessories

I just got hold of an 84 300SD with 87,000 miles on it. I haven't started any of my initial maintainance yet (filters, hoses, compression test etc). There were no maintance records with the car so I will be replacing a lot of the "minor" stuff. It starts great on only one crank and shuts down perfectly as well. Not having owned one before I don't know if what I am seing is normal or not. When you press down on the accelarator there does not seem to be a direct response from the engine(rpms). It does climb up there though.

w126 1985 380se white smoke exhaust after sitting and cold. white smoke goes away once engine is warmed up. someone told me that this indicates antifreeze in the cylinder. any suggestionws?

I need some help in a bad way. I have a 300SD and the oil pressure gage is doing strange things. Once the car warms up and I am under power, say more that 1500 rpms the oil pressure gage will just drop to zero. If I let off the throttle and slow the car down the gage then will immediately peg to 3 then come down to between 1 1/2 and 2 at idle like it should. I only have this problem once the car warms up and when the gage drops from 3 to zero it is like someone just flips a switch and then also the gage will just jump around sometimes. My question is do I have the oil pressure sender failing or is my oil pump failing?

I have an 81 300sd with 334,000 on it. Have changed the flex plates and recently had the driver's side rear wheel bearing looked at because i was experiencing a clunk when i put the car in reverse. The mechanic said the bearing was going, but tightened it up and now the clunk is better ( a temp. fix... part is on the way...) but i have been noticing a 2 stage clunk when i accelerate after the car warms up. if i depress the accelerator quickly and let up quickly it clunks on the depression and release, also when the tranny downshifts when there is no load on the drive line, like when i am coming to a stop going up hill. any clues?