Hello One and All! My name’s Scott and I am a mechanoholic. I am trying to be in recovery but then I bought this MB.

As I Get Older I really can't afford to be pulling out any more hair, so when I started trying to diagnose this current problem I decided to turn to the Internet and google led me here.

I am certain we will be frequent visitors in the years to come. I have always been a pretty fair mechanic, but without shop manuals it has been a pig in a poke under the hood of this 500SEL.

This is my third MB. After spending thousands restoring my 280C and finally after a few years of enjoying her then seeing her go down the road without me, I thought I would never again be in this market. But this pristine and near-perfect 85 500SEL just waived its wipers at me and here we go again.

I used the excuse it was a Christmas Present for My Wife!

She has 192,000 well cared for miles, The MB, Not My wife. My brother and sister-in-law owned her from birth and were meticulous about her care. His wife drove her until we got her in 2003.

My wife now drives it and for several years now she drove it one block to the gallery and one block back each day. Now we are in our new home four miles away and she drives that all highway. About once a month we will take it to the valley about 50 miles away and I will work it out a little on our coastal roads. Blow out the carbon if you will. I also take it to the store on occasion if I am not in work clothes.

For the last few months, When she started it (Starts first time, every time!) it has required more and more time to warm up before she can put it into gear and head down the one block. It would not die, just, best description, "choke out?, Bog?" and return to an idle when she let off the gas.

Now I have been tracking this for months when I could give it some time. As of the past two weeks it also has a power loss warm, when at the low end of the RPM range and when pulling hills. Big time on hills. It reminds me of a nearly plugged catalytic converter, but I have not gotten into it that far as of yet. I believe I have read all the threads but nothing fits exactly as this is.

I have already done the following;

I think Unrelated?, Replaced the cruise control switch, it would set itself on bumps due to being broken inside. (Note: Shop replaced switch, now it will not work at all, Shop mechanic says he has no idea why and cannot fix it!) But it is better than taking off on its own when my wife is driving her. So I will look into it when I have a manual.

Replaced the rear fuel filter.
Replaced the Plugs with Bosh Platinum’s.
Replaced the Distributor Cap with Bosh Cap.
Replaced the Rotor with Bosh Rotor.
Ran a bottle of injector cleaner thru it.
Cleaned Air Filter.

Pulled the Electrical Plugs on Cold Start Valve, Temp Sensors and several other sensors and burnished the pins and then put oxguard on them to prevent corrosion. Here at the beach this is a good Idea anyway.

Checked all the vacuum hoses easily accessible for cracks, but I hear no vacuum hiss from anywhere.

Checked Plug Wires, Clean and good continuity.
Oil Level OK and Near Fresh.

Ran the motor and looked at and listened to everything carefully and seen nothing out of place or unusual. It is full factory. All but one air cleaner mount rubber is in place.

O.K. HELP!! I don't know what to do next. As I do not have manuals, I first need to secure them.

I have read some terrible reviews on the Chiltons, Haynes Paper manuals and the ALLTECH C.D. Rom Manuals. I have tried to see what kind they have in the Fast Lane reviews but those pages won't come up. Any recommendations. eBay has some offered for $10.00 but they have not responded to my inquiry about who wrote theirs before I buy. I guess anything will be better than nothing but what is good?

Thanks in advance for your assistance, I promise, as I tinker I will share also, as I guess I should now get the SL I have always wanted and make them a hobby. Unless you know of a good twelve step for MB Program.

Scott

Sounds familiar. I'd do a search on platinum plugs and see what that turns up.

__________________
1987 300e manual 250,000 km (sold)

Carefully checked gap twice. Plugs that came out were platinum4's

Might want to check the fuse on the OVP (do a search on OVP) should be behind the battery (behind the black plastic cover?) a relay with a clear plastic cover on top with a 10 amp fuse underneath the lid... might want to take it out and shake it to see if it rattles at all ( the most basic and primitive of all OVP tests)
Did the hill power problem correspond at all to the platinums?
Even if not you might want to get those out of there and replace them with Bosh coppers ( about$1.00 each) Mercs don't seem to like those high quality plugs as much as the cheepos. Check with your dealer for the right plug # but they should probably Bosh D7 D8 D9 DC7 DC8 or DC9.
Good luck.

Edit I see this thread is the active one You might want to delete the dublicate.

__________________
-Marty

1986 300E 220,000 miles+ transmission impossible
(Now waiting under a bridge in order to become one)

Reading your M103 duty cycle:
http://www.peachparts.com/shopforum/831799-post13.html
http://www.peachparts.com/shopforum/831807-post14.html

Hey, Thanks all.

I just put in the new platinum’s, cap, rotor, etc. Once it became a road hazard for my wife to be driving I have had to pour attention into this.

You know the drill. Wife complains about squeak, spray some oil at anything. Becomes dangerous for her, spray oil on everything. Until this week I took a peak for the squeak, but was not real serious.

That relay, one by that description is in the fuse box. Has a 10 Amp new style U.S. fuse flat on the top. Or is it behind the battery? There is a vacuum valve with an electric wire in the latter and some other devices down in there!

Scott

Try putting some Bosch coppers in place of the platinums. Not too expensive.

Hello,

When looking for the OVP relay, I was unable to find a relay behind the battery, but one matching that description was in the fuse box. According to the owners manual that is an empty space as I show in the picture below.

When I first shook it, it rattled a fair amount but with subsequent shakes it quieted down. I would expect some rattle when FD&H (Fat Dumb & Happy) as it is referred to in electronics. This is when no influence is applied. Also I would expect pieces of a blown relay to find a resting place inside when shook and then it would quiet down.

I metered the legs, the coil has continuity. The other pins are open. I do not know what it should be when FD&H. I measure no resistance in cross leg checks, I would have thought there might be some as the diagram on the relay cover shows some resistors on cross legs unless I am reading it wrong.

Any more information on this relay?

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