86 420 sel

[walt12]

Hello People,

I have just got 86 420 sel and I love the car. I would welcome any tips on what I should do first as far as maintance.
T
he car has 240,000 miles on it. It runs pretty good. But as a newbie to Mercedes I just want to know what I should do first. I have 4 Porsche 944 and the first thing I did when I got them was to change the timing belt. Do I need to do something like that to the Benz?

Also the cars has radio problems I would like to keep the Becker Grand Prix, to avoid the hassle I may just put in an aftermarket unit.

Thanks

[Two560Two]

Replace all fluids and filters and DEFINETLY have the timing chain/guide rails checkd out. At that mileage, the chain and tensioner should of been changed at least once of twice alreadly. If Not then I would do the job right away. If you have front end noise then check all the ball joints and bushings including the shocks. As for the becker radio, I have one here from my 87 laying around so if you are interested just PM me. Radio and cassette DO work. I upgraded to a MF2910 mercedes unit from a more modern mercedes.

[Jim B.]

There are a few tips for you at www.mbcoupes.com buyer's guide

If there are no prior records or books with the car, you should definately do the timing chain, tensioner and guide rails, even though there is nothing in the owner's manual about that, because there could be serious damage if the timing chain jumps the rail....don't go there. After some years and mileage the guide rail (made of plastic) gets brittle anyway, and is ready to crumble.

The radiator originally had an unreinforced upper hose neck, so it would sometimes crumble and/fail after some years, so if I were starting out, and had the original radiator, I'd suspect it would be a good idea to replace it, with a BEHR unit.

Why not take out the plugs and inspect them also? If it needed wires, the Beru ones are supposed to be very good.

I also agree with the poster above who said change all fluids and filters, that would establish a ground zero time and mileage point for taking care of the car.

These cars are not too bad to maintain, but expensive to "catch up" if maintenance has been deferred.

Good luck
Jim

Oh yeah, the Becker radios of that era were kinown to be troublesome, so it's
not a bad idea to get a replacement stereo for the car.

[Hit Man X]

I agree 100% with the upper guides and tensioner. Chains hardly ever break, so that's for you to decide. I probably wouldn't mess with the chain until 300K or so as then it'll be stretched and at that time you'll need lower guides too. I doubt that M116 in there is on the original chain/guides. Mine came apart around 221K. Now it's getting an M117 transplant.

Also, a newer radio is smart. Stronger FM tuner, CD capacity, more than six FMs, etc.

[STORMINORMAN]

Try to find a good indy shop in your area: have them check out your car as described above. Start to develop a long-term relationship if you can. Find other W126 owners in your area for their advice.

A tranny service is cheap compared to any tranny repair: did you get any service records with your '86?

Synthetic gear oil can help your mileage and you probably won't have to ever change it again. IMHO, almost any HDEO 15W-40 oil works just great in these W126 cars. Dino or synthetic, take your pick depending upon your desired OCI. Hengst oil filters are cheaper if you buy a supply.

If you replace the belts and hoses now, you will have replacements you can use if the new ones ever fail: I carry a set of used hoses and belts in a bag in the trunk on a long trip.

After the timing chain issue is settled I would recommend a series of Auto-Rx treatments: you can search here or go to "BobistheOilGuy" for all you ever wanted to know.

If you have the room and the $, a running parts car has the potential to extend the life of your car for a long time.

Cheers!

[Daryl Baines]

walt12

I agree with STORMINORMAN I am a long time user of Auto-Rx for sludge and main seal leaks it has worked great for me.

[Rockman59]

Walt12 said: Also the cars has radio problems I would like to keep the Becker Grand Prix, to avoid the hassle I may just put in an aftermarket unit
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Update your audio with a new AM/FM/CD player. You can get a great sounding unit installed for $200 or less. The older Becker Grand Prix is one of the worst sounding audio systems in the world. And you can save the Becker in case you ever sell the car and the new owner wants the stock system.