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1993 400E
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Discussion Starter #1
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This is a picture of my 400E distributor dust cover. I wanted to take it out to have a look at the back side of it because I know that they can become degraded and cause issues. My car is relatively new to me and wasn't running properly when I bought it. Because of the area where i purchased it, I had to take it to a regular mechanic shop to diagnose the issue. They ended up replacing both distributor caps and rotors and they also "sealed the dust caps with silicone" because they found a bunch of condensation inside the distributors. After I got the car back, it ran great for about 500 miles but now it's not running right again; sort of the same problem as before, the car cuts out and or misfires during normal driving although it starts fine now after driving for a while where it didn't before. My though was too pull out the dust caps to have a look at them and possibly replace them but when I tried to pull out the first one, it's stuck. I don't see any silicone anywhere but I'm thinking they maybe coated the back of the dust cover and now it's stuck there where it resides. I don't see anything else holding the dust cover where it's at right now unless I'm missing something? Shouldn't it pull right out after taking off the rotor? If it is being held there by silicone on the back side, could this be causing my running issues? Any suggestions? Also, pretty sure I still have the eco junk wiring harnesses which I plan to replace soon too so that's a whole other story....
 

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1993 400E
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59 Posts
Discussion Starter #2
Also, the new distributors/rotors are Beru brand.....the shop didn't say anything about replacing the dust covers so not sure if they are new or old but they look new and are black in color like the new cap; most of the ones I see are orange so these might be new dust covers.....I just can' take it out to look at the back side......the inside of the cap looks good to as far as I can tell anyway....
 

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W124
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5,296 Posts
No comment about your mechanic's aptitude.

These cars have run hundreds of thousands of miles without having someone seal the distributor. Good luck trying to get them off - hope you can without too much trouble. Get a metric hex head set and remove the rotor mount. Then replace the dust shields yourself. Inspecting them isn't going to be a foolproof tactic.
 

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1983 BMW 633CSi {yeah i know},88 300CE, 93 300TE, 94 SL500, 98 ML320, 01 cl500, 02 ml320
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No comment about your mechanic's aptitude.

These cars have run hundreds of thousands of miles without having someone seal the distributor. Good luck trying to get them off - hope you can without too much trouble. Get a metric hex head set and remove the rotor mount. Then replace the dust shields yourself. Inspecting them isn't going to be a foolproof tactic.
i worked in the foreign car wrecking business over 25 years. and honestly silicon seal was a red flag to triple check anything mechanical on the car before selling. that is not even shade tree mechanic quality. your wiring is the culprit here if not already replaced.
 

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1993 400E
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59 Posts
Discussion Starter #5
Yeah I have a feeling that the issues are related to my upper wiring harness which I wll attempt to replace soon. I just wanted to make sure that silicone on the backside of the dist dust cover wouldn't be causing any issues but I can't even pull it off; pretty sure I have the rotor mount off too as was mentioned unless I'm missing something, I'll post some better pics tomorrow
 

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W124
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Looking at your photo again. I am not familiar with that black shield that is in your distributor. The factory dust shield is orange in color and much flatter. I think you have some hybrid set up.

The textbook failure of M119 dust shields include one or all of the following:
1 Reliable cold starts but misfires develop within a few minutes.
2. Misfires develop and degrade to the point the car won't idle
3. Perfect cold start, normal running for ten minutes, shut the car off and it won't start or has bad misfires

Not sure what your original symptoms are. Changing distributor caps and rotors can improve the situation for a short period (one of your symptoms). Since you can't get your shields out (and they look like someone cooked them up) break them up and get the pieces and the silicone out before you suspect anything else.
 
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