Help! 92 300e 2.6 mechanical Q's
I recently acquired a 92 300e 2.6 w/ 120k Miles... The car was a Palm Springs car, and has appeared to have synthetic oil most of its life (under the oil-fill cap, the metal has virtually no sludge whatsoever!).. i have some questions about this car, that hopefully maybe someone can voice their opinions on...:
1st issue:.. Air does not come out of the Center vents. The dealer whom i bought this from has an independant (not an MB specialist) mechanic that he goes through, and his mechanic's opinion is that there is a sort of "valve" that needs to be replaced- and that its located wayy in the back of the dash (and its a apprx. $900 (!) repair).?? does this sound right? I must mention that air does blow fine out of the side vents, and the switch assembly does seem to be working properly. This symptom happens reguardless of the temperature setting... $900 seems like an AWFUL lot to get this problem taken care of.. The dealer said they'd be willing pay roughly half of the bill, *if its not that expensive*... Should I consider taking this to a independant MB shop in town (instead of the dealer's "regular" mech.)? heck,i'd possibly like to tackle this myself, if its not *too* hard for the DIY'er.. ..Any opinions??
2) car has a *slightly* uneven idle.. almost like there's a baby/tiny intermittant miss in the engine. Not excessive, just barely noticeable. I replaced the Spark Plugs w/ Bosch HCDC-9 (btw- should I have used the heaver-duty "0" model plug?).. I did notice that the plug wires have some heat-stress marks on the wire insulation.. I suspect these to be the Original wires. Do the Wires usually start to lose their efficiency by this point in time? Should I also consider replacing Dist. Cap/Rotor?(I am guessing the car still has its' originals)... I did run a bottle of Techron cleaner, which helped a little bit.
3)The trans seems to have an occasional firm shift from 1st-2nd gear.. (not bad, just that it kinda softly "snaps" into 2nd).. Is this just a common trait of this transmission? Does changing the ATF to Synthetic help in some cases? (i've heard mixed reports).. Other than the 1-2 thing, it seems to shift great. My guess is that it could use a fluid change anyway, if synthetic might possibly help, i might give it a shot..
4)Every once in a while (and seemingly only in the mornings- 45 degrees or so btw), i will hear & feel a slight "clunk" from (i'm guessing here).. the rear of the vehicle, after i have shifted into Drive gear (after reversing out of the driveway)...Could this be a bushing/flex disc issue possibly.. ?? As soon as the clunk noise stops, the car moves forward fine. seems like the noise/clunk happens first though, before i can start moving. Weird! For the rest of the day, the car is fine- no clunk.. just that initial one in the morning.
5) Lastly.. I just got the oil changed to Chevron DELO 400 15w40. However, the place that did the oil change seemed to put a little too much oil in the car.. its approx 0.25 inch above the full mark on the dipstick. I'm not sure if i like that..Is this bad? Also since the oil change, I notice in the mornings, their is now valvetrain noise for the first 2 seconds -a light "tapping"..which soon disappears..which did not seem to appear w/ the old oil in the car (which, btw from all indicactions was Synthetic, and at the proper oil level).. could having too much oil in the crankcase cause this? Or, Being dino oil and/or at the wrong viscosity? i'm stumped!
Thanks for any and all help, you guys are wonderful!!!
1992 300e 2.6.. 120k Miles