E500 is shaky when parked, spark plugs?

[cheinze]

Hello guys,
I am probably the newest guy in your forum and very pleased for being here. I just recently bought an E500 Limited Edition 1995 in Mexico, yes! the only one here! it has 225K KMS a lot but not for the unbeatable W124.

Before changing distributor caps, rotors, cables, engine harness, all filters, all new fluids and sparks I was feeling some strange behaviour when parked and the engine on, the RPMs are not very steady, if I go out and hear the rear muffler you can hear a little bit that one of the pistons fails a little bit (misfire). Another issue is that when I am just about completing a final stop in a stoplight it seems that the engine might die but it recuperates and still on. It shakes a little bit.

After changing all those components my car still having the same behaviour, is there something I am missing? I used the following electrical pieces as a replacement:
Bosch F8DC4 Original Equipment Type Copper Spark Plug
Bosch 09366 Premium Spark Plug Wire Set
Bosch 03367/1235522430 Dist cap
Bosch 04271/1234332422 Ignition Rotor

Someone told me I should use original MB sparks, I don't read any failure codes, can anyone have a clue of whats going on?
many thanks!

 

[jnes]

Re: E500 is shaky when parked, sparks?

Hi,

Welcome to board! At first, check the fault codes. You can check them by blink code reader. How does the distributor insulator caps look like? If there are cracks, they could cause misfire. I used on my misfiring repair bosch parts except ignition wires..

-jnes

 

[gsxr]

Re: E500 is shaky when parked, sparks?

F8DC4 plugs are correct, no need for OE/dealer plugs. You should clear all codes and then see if any return quickly; existing codes will likely be useless. Since your ignition system is all new (except for the insulators behind the caps, I'd start by checking all the vacuum hoses/tubes. Shaking feeling is almost guaranteed to be failed engine mounts, but that would not cause the RPM's to drop at idle.

BTW, welcome to the forum!

 

[cheinze]

Many thanks guys. Yes, caps are Bosch brand new, old ones had cracks on it.
Will check for codes next week, do you think this codes could pop at a MB dealer? They can scan it for me for free.
We CH are the insulators behind the caps? Any part number I could use to buy and change them?

Vacuum system looks like a possible issue, any good guide to check it?
Many thanks!!

 

[jnes]

A119 158 01 88 is the part number for insulator plate. They are stupid expensive from the dealer. Mine costs about 115 € per piece if I remember right. If you decide to replace these, change also o-rings. They are between rotor caps and insulator plates. PN is A 020 997 05 48.

Bend the vacuum lines little, if they crack or there are cracks then they need to replace. If there are major leaks in vacuum system then headlight adjustment won't work or the backrests won't fold. I'm not sure does your car has euro headlights, if not then you don't have headlight adjustment.

 

[cheinze]

Many thanks for your prompt responses. I already changed the caps and checked some leaks on the vacum tubes and things improved but not totally. So I made the last step, the coils, and yes, it worked! no more shakiness in my car. It even runs more smoothly and powerful. thanks again for your help guys!

 

[J-Sauce]

There is a difference between "caps" and "cap insulators" on these cars. The insulators are plastic rings that go BEHIND the rotors, and caps go in front of the rotors. Their purpose is to protect against arcing from the rotor to the cylinder head by providing a non-conductive barrier. It is worth checking to see if yours are damaged, even with hairline cracks, as this part is often overlooked and will likely be original.

 

[AMGTesTDriverNJ]

Post Pictures!

 

[Hotbasco]

+1 on vacuum lines
then do motor mounts (& trans mission mount)

 

[need2speed]

+1 on motor mounts....and please post pictures!