Dark

I’m a NOOB. Lurked while I owned my W115 300D I had been driving the last 3 years & recently sold.
I appreciate the knowledge being shared here & hope someone can answer a couple of questions about the W124.
I bought a 1987 300E with 91K miles. It has a solid body & clean interior. It was garage serviced but probably not as often as it should have been. It was a city car (Charlotte, NC) & only got about 5k miles a year. I started with oil & filter, & a new air filter. I plan to put in new plugs & wires next week end and change trans fluid/filter & rear diff also.

Questions:
1. Should synthetic tran fluid be used?
2. Should synthetic rear diff fluid be used?
3. At idle it misses & when you try to engage the cruise control it speeds up but doesn’t engage, vacum leak? I just drove it 400 miles today & it got 26+ MPG so I don’t think it’s running to bad while driving, just at idle.

Any suggestions appreciated. I’m very excited about this car, nice solid feel & pleasing to the eye, just needs a little TLC.

Kestas

I'm not a big fan of synthetics, with the exception that I believe they should be used in the differential. Synthetic diff fluid will give an incremental increase in gas mileage that will offset the initial cost of the fluid. Since only 1-2 qts are used, this cost is negligible compared with engine or trans oil. I base this on the fact that the trend among manufacturers is to use synthetic for factory fill in the diff to boost CAFE measurements.

You can't go wrong with synthetic trans fluid. You're doing it yourself so you're saving lots of money to begin with.

Clean the throttle body bore. Maybe the idle will perk up. If not, hunt for a vacuum leak.

Don't forget the fuel filter, brake fluid, coolant, and perhaps the ps fluid. This gives you a fresh start with the car. That would be my style with a new purchase.

Dark

Kestas, thanks for the suggestions. I agree, a fresh start would be good, I'll get to know the car better & know where the service stands then.

Will gum out or a spray type clean the throttle body bore? Or perhahaps some injector cleaner in the fuel would help?

Again, thanks for the input.

Kestas

I wouldn't expect much help from the injector cleaner in the fuel on the throttle bore. It's best to take an old toothbrush and some solvent and scrub away. You'll have to do a lot of scrubbing, the deposits don't just melt away, they're very tenacious. Any solvent would work... throttle body cleaner, carb cleaner, WD-40, mineral spirits. Also clean the butterfly valve edges.

Dark

Over the week end I put in new plugs, plug wires, rotor & distributor cap, cleaned the air intake and the air filter is only 2 weeks old. The idle is now smother (not silky smooth but smmoother) & the tach won't bounce, but I still feel like it is missing when I let off to slow down for a stop, at the stop it is better but not perfect & it doesn't start as easy as I think it should.
I'm getting 24 mpg combined & 27.5 mpg hwy.
Any ideas to get it "silky smooth" as I've heard they should be would be appreciated

Thanks in advance

Dark

Oh, one more thing. I came across some old post in which people were offering copies of the W124 service CD for $10.
Anybody out there still able to provide a copy?

Thanks

Kestas

Yes, I can provide a copy. PM me if you're interested.

Dark

Kestas, Thanks much PM'd you