e320 help
 

When stopped at the light with car in drive and foot on brake,
car has very significant shakes/surges, but stops as soon as I move on. These aren't the vibrations caused by the engine mount problem. Wondering if it is a tranny issue or....????

thanks guys.

Does the vibration go away when you put the gear in neutral or park?

What year is your car? Do you have a W124 chassis E320, or a W210 chassis E320?

yes it does go away in P or N. It is not really vibration but jerkiness ...thanks buddy

Sorry it is an e320 coupe 1994 W124

Any ideas???

If it was just a vibration, I was going to suggest it was your motor mounts.

But since you describe it more as a shake / jerkiness / surging, it sounds like the car is misfiring.

Sounds like you might have a bad connection between one of the three coil wires and the resistor boot.

Do you know if your engine wiring harness has been replaced? It causes all sorts of weird problems. Degrading insulation is a problem on '93 to '95 E320's...

Thanks buddy...I will look into that...

do you find the problem??
let me know

I looked around....I am scheduled to take it into a shop on thursday.......I will let you know..thanks.

I am back!!! R-C imports (Rick ) rockville...did a very solid 90,000 mile service on my coupe. The jerkiness described went away. He says it was to do with the tranny needing a fluid change etc.
That was the good news..after a week it is back again...so I can't post anything solid here. I will have to take it back for him to look at. From what I am hearing, it could be a tranny problem. Thank God I bought that warranty...!!!we' ll see...

I had the same problem. I bet you need new resistor ends on your spark plug wires! That and the correct (F8DC4) spark plugs will correct your problem. Easy DIY and cheap, too.

Wow...I took the car to a very highly rated guy on this site and I can't believe it could be something as minor as you indicate.
I will look for the parts from MB and try it..I will post after...
thanks in advance.

It happened to me. My mechanic at the time missed it. I had similar symptoms as you, and took it to a well-regarded shop in town that specializes in European cars. He has been working on Mercedes since he was 16. He couldn't fix it and had me take it to the dealer.

The dealer quickly diagnosed the problem as one coil wire with a bad connection to the boot.

Needless to say, I have a new mechanic.

well...which is which? these ar two different solutions right?
Coil wire or spark plug wires?
Could be both I guess...might have to take it to a dealer for diagnostics then unless these ar the same solutions...?

thanks in advanceh

Spark plug wires aren't cheap. Resistor ends are about $50 at the dealer. THey also have the correct plugs. Coil wires I haven't replaced. I'm not sure they can diagnose the exact location of the errant electrons. If you're under warranty, let them fix it, whatever it is. Just point them in the right direction.

You have three coil wires and three high tension leads that piggy-back to the next cylinder. So each coil wire is responsible for firing two cylinders.

The coil wires are made of solid copper and virtually never wear out. I don't remember how much they are off-hand, but I'm sure they are over $200 for a set.

The coil wire ends (or boots or connectors) are about $7 to $10 each, depending on where you buy them.

95% of all missing or misfire problems on M104 engines are due to a bad connection on these resistor boots.

I forgot to say that I wouldn't recommend replacing the coil wires because they just don't wear out.

If you do, only buy original MB wires with the star logo on it because they are made of solid copper.

Aftermarket wires, even Bosch, are much cheaper but are not worth it as they are made of a copper / silicone blend and will wear out.

You get what you pay for.

So..is the resistor end part of a new plug wire? or is it a separate item?

Thanks.
I need
the spark plugs
the new spark plug wires
new resistor ends?

Resistor ends screw off and on the end of the plug wire. They are what attach to the spark plug to the spark plug wire. They are about the size of a small tube of toothpaste. Get the plugs while you are at it. No "R" in the part number of the plug. Means resistor. Will burn up the wire ends from too much heat.

You are calling them spark plug wires, but they are technically coil wires.

I wouldn't recommend replacing them, but you can if it makes you feel better.

Remember, it's not the coil wire that goes bad, but the connection with the resistor end.

guys..really...thanks a lot.
So since the car just had a new service..I will go ahead and get new resistor ends and new spark plugs as stated...
I will post when after I do that...

I was about to buy the resistor ends when I was thrown a curve ball. How many do I need? point is there are six cylinders but there are three coil wires and three plug wires?
ANy ideas?
thanks.

There will be three of each type, six total. One type for right under each of the three coils, and one type for the ends that attach to the longer wire.

If you're buying at the dealer like I did, they will understand.

Exactly. There are three coil wires and three "high tension lead" wires, so there are six resistor ends - three for the coil wires and three for the other wires. They are two different types and they are priced differently.

The main fail part on these ignitions is the little spring connector between the resistor and the spark plug tower. This connector spring is part of the resistor boot under each coil. The resistor itself and the top coil connector are usually fine. But the bottom connecting spring fatigues from both the heat that is trapped at the plug BC this cavity is encased by the coil and it is simply a compression contact. Not the best electrical connection, but BC the coil is on top , that is the design they used.
Once the spring looses its tension , the connection becomes weak [ as it is simply a compression contact].
Results are mis-fire at that plug, plus a possible mis-fire at the
other plug due to this being a series coil circuit. [ If the spark jumps to ground at this weak connection, the other plug will fire, however]
The other 3 resistors do not have this problem as they have a snap connector at both the plug end and the coil end and the plug cavities are open to some cooling.

So , mostly. you can rectify the mis-fire conditions on these by simply replacing the resistor boot connector under each coil.
About $7 ea..........

Did the problem went away after you replace the part ?? I have pretty much the same problem but it just happen once a while. I can put my on "P" or "N" and the surging will be gone, question is how that got to do with the spark-wires if it's bad, the engine should have rought idle and mis-fire all the time right ??

Good day.

Kenny:

It may not seem intuitive, but it works. My car only "lurched" under load. Never any perceptible difference at idle in P or N. Change out your plugs with Bosch F8DC4 only and replace your resistor ends.

Thanks...the problem is gone. I had the plugs and wires replaced.
it cured the problem. I tried doing it myself but it was too much hassle..so Ifound a mechanic to do it.

make sure you have the correct parts..

Just want to make sure that I'm going for the correct parts.

Are the part numbers 000 159 36 42 (about $11) and 000 156 71 10 (about $18) ??

Thank you.

Allan