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Step by Step - R&R of Suppressor/Distributor Cap & Rotor

8902 Views 6 Replies 3 Participants Last post by  LTYLER
Morning W124 Owners. I have put together this little step by step for anyone who may need it. It’s definitely not textbook but I fault it may help anyone like me who is just trying to maintain the W124 without having to go and spend a fortune at the dealers or Indy’s every time a piece of plastic comes loose! This is quite a simple procedure and it took me about 1.5 hours to complete.

I completed this work yesterday after finding my Suppressor cap or distributor cap dust cover was loose from the distributor cap. I found out that the distributor cap Plastic connectors that hold the suppressor in place had snapped on the right side. As I needed to remove and replace this I also changed the Rotor and cleaned the Distributor cap of any corrosion inside.

1) Remove Suppressor cap by Pulling left & Right side ends out from Distributor cap. This is held in place by two plastic connectors. Be careful.

2) Carefully pull Spark plug ports (Ignition Cables) out of distributor cap (Make sure you remember the sequence numbers of each one

3) Now for the fun stuff: There a three hexagons sockets that need to be removed. One in the left and one in the right side of the top and one at the bottom right hand side “This one is an absolute bitch� Get underneath this area with a wet rag and scrub as mine was very dirty and completely clogged. I could not even see it until it was cleaned. Unscrew these three Sockets. The bottom one will take a long time as there is no clearance the fan in place. Some people remove the fan and rad but I choose not to, Depends on how you can work.

4) Pull off the distributor cap and remove black plastic casing revealing the orange Distributor. Mine had some corrosion on the metal connectors inside so I used a file to remove this. I also cleaned the unit of any dirt and dust. A new distributor is around $ 100 + bucks but I felt this part could be salvaged with some cleaning (The choice is Yours)

5) Remove the Rotor by removing 3 Small Hexagon Sockets. Be careful that these don’t fall or get dropped; there is a lot of room for these things to get lost.

6) Now please bare in mind that this is just what I did. I felt it necessary to clean this area, as it was filthy. There was a big build up of dirt/Oil Engine gunk deposit at the bottom end of were the distributor sits (Next to the surp Belt) so I went in with a towel and got all the thick stuff out and used Brake cleaner to remove all the remaining. This made the whole unit look great and very clean. Back to it’s original finish.

7) Installed the rotor and replaced Hexagon Sockets x 3 (take extra caution when tightening these sockets and one could snap and you will be screwed) This item cost between $30-$40.

8) Installed Distributor cap and cover and replaced hexagon sockets x 3 New cover was $12.
9) Re wired Spark Plug (Ignition Cables) in correct order. Also relined the plastic channel where the spark plug wires (Ignition Cables) run on top of the engine (left side as you face the engine).

10) Re-fit the suppressor, (Distributor cap dust cover) and clean engine bay, Make sure that you have not left any tools lying around. Start her up and make sure everything is ok. Mine fired right up and she normally does.

I have included some pictures of my procedure. I hope they help. Also see the Braingears link below courtesy of 67_250SE.

If any one has any corrections to make or suggestions please feel free to do so. As stated I am a beginner to all this DIY Mercedes at home maintenance stuff.


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Lee, I am glad that you were able to get the job done. I should have taken pics of my own procedure, but once I get going, I forget to take the pics. I am glad that the info in the link was helpful.

Lee, regarding your step #3. It is not necessary to remove the fan AND the radiator. I only removed the fan and the shroud, that gave me plenty of clearance.

Doesn't your car run that much beter now?

what year is your 300E?
Yes I’m glad too!!!! Thank for all your help. So far i have changed the water pump "8 hours work" Coolant fluid flush. Front rotors and pads and now distributor cap/rotor so i am managing to do these little jobs myself without destroying the car !!

She is a 1990. It's quite a story how i ended up with her. I was living back home in the UK and was in the process of moving over here to be with the wife. She was driving some Geo Trakker or some POS like that So i told her to go out with the father in law and get me either a C class or E class. I told her go between years 1990 and 1997. I gave her $8000 to spend and not to go over 90k on the miles and i wanted a very clean car. I knew absolutely nothing about the U.S. used car market all i knew was that iv grown up with Mercedes and i wanted one here.

So i get a call from the father in law saying he found a 90 300e Black on Black with 73k in mint condition for $7500. I was like great go get it. So he went off with the wife and test drove it and all that fun stuff “wife fell in love with it" Car was mine 30 minutes later for $6000.

So i get here in the U.S. and go to the DMV to register it and when i pull the title it states Salvage restore !!! I was livid that a car was bought with that title and for that price. I done a complete history check from carfax and even got in contact with the MB dealer in LA. to find out some more info. They told me the car was owned by a doctor there and basically it was his wife’s car. It went there every 3k. He owned it from new $51275 back in 1990 !!!!! Basically the car was MB dealer serviced and maintenance performed. They sent me over the full history which matched everything in the log book up to 72k

The car fax states it was in a collision in may 2001. The dealership told me that in Late may 2001 the guy who owned it went in there and bought a 1995 E320 in mint condition and said that my car was salvaged by the insurance company.

So my guess is the place my wife and father in law bought the car from basically bought it at auction for a grand. Fixed it and made 6 on it. I called him and he did state that he informed my wife that the car had a salvage title!!! He told me that it was involved in a collision in LA, Front left fender/hood and screen had to be replaced and some frame pulling needed. I must admit they done a very good repair job. The paint job they have done is immaculate you can not tell in any way no matter how close you are.

I must admit i wanted rid of the car as soon as i found out but i just cant let go. I love the way this car drives and looks. I can’t think of one car today in the $30-35k bracket that would have a better build qauilty and feel as good. Obviously i would take a 500SL over it any day of the week ! But im a 24 yrs old guy who just wanted something a little better than a civic or Camry.

She needs a new A/C compressor that i will try and complete when i have a long weekend available but apart from that the car runs great and looks great. Going to upgrade to 8 whole MB rims pretty soon but everything else is going to be kept stock.

I’m actually in the market for another 300E as i can't stand the Durango "The Greedy gas guzzling pig" But that’s no big rush, i will just wait until a good deals comes along and a real nice ride.

Have a good day

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That is a great story. A lot of people don;t care about a salvage title. As long as you can get insurance for it, who cares. It just means that when you sell it, you have to inform the new buyer, that's all.

If the repairs were well done, then you are good to go.

Price is a relative thing. Sometimes I thinkt hat I paid too much for our 300TE. But the PO had done a lot of work on it, he works for the local Benz dealer and because of his discount, he was able to do a lot of this work for a reduced price. For example, it came with really nice eight hole alloy wheels (including the spare wheel/tire).

He also had a complete valve job done.

This car will easily last another 200k miles!!!

Good luck with your car and keep psoting pictures of your work. Maybe this is the time to get Euro headlights. [:D]
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leetyler, in your last few photos i see this reddish wire coming out where your spark plug wires are and going to some sensor(?) on the exhaust manifold. what's that? i'm not looking at my engine at the moment, but i'm pretty sure that my car doesn't have that.
merc-one - 4/11/2006 1:11 AM

leetyler, in your last few photos i see this reddish wire coming out where your spark plug wires are and going to some sensor(?) on the exhaust manifold. what's that? i'm not looking at my engine at the moment, but i'm pretty sure that my car doesn't have that.
EGR ???
I have no idea, Iv never really looked into it, maybe someone on the forum will be able to assist.
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