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Discussion Starter #1
Hi all, I'm a proud new owner of a brilliant green 95 E420 AMG. I started out wanting to purchase a 300TD for fuel mileage, and started doing research on the W124 platform which brought me to the E420.
I found this one with 152K miles on the clock, in very good shape. This was actually from a dealer (not my first choice to purchase a car), but got a very good deal.
Well, I have been driving the car for the last few days, and everything has been running pretty well, engine had great power, trans shifted pretty smooth, overall great experience. Today, during my commute home from work, I got a sudden lack of power after getting on the gas pretty hard. I pulled into a parking lot, and at low speed could tell something wasnt running right (hitting the gas at low speed in drive). I even took it back into the road and went manually through the gears starting with 2b, and same deal. It seems to bog, and even after getting into the rpm's it lacks tremendous amounts of power.
I let it cool off for a while, and it actually seemed to almost retain 99% of its power, but once warm, same thing. (Warm being around 80-90).
I had planned on giving it a tuneup, changing oil, trans fluid, plugs, fuel filter etc.
It does seem to run slightly rough at idle, but it has since i first purchased it.
Ive checked for smoke( possibly head gasket), and checked engine oil dipstick, with no indication of any coolant. The engine is relatively quiet revving it, with a little bit of tap, possibly sticking lifters or valve tap. Very faint, but it is there.
There is no check engine light, so I am stumped as to what it could be. While I am a mechanical car guy, I dont have much experience with this car or mercedes in general. I planned on a service manual when I did my tuneup.

Any ideas as to what the problem could be? I have searched the board, and the only thing I could come up with is a post regarding a clogged catylitic converter. Almost same symptoms, even lacking power when warm.
Any ideas/suggestions? Thank You
 

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New Project: 1994 E420-------1986 300E (SOLD)
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53 Posts
New sparks, rotor and distributor is a good start.

Do a search for ASR issues. Does the pedal feels like 1/2 way down?
 

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2000 e320 4matic
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3,401 Posts
has the wiring harness been replaced?
 

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1995 E420
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56 Posts
Do you have ASR option? If so, you could have problems with that system. As PESUAZO states above, the issues are well documented. The other consideration is the wire harness. Again, the topic and troubles are well documented.
 

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W124 400E, W126 500SE
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971 Posts
distributor or a coil, change it now or you WILL ruin something (oh, and change the O2 sensor...)
 

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58 Posts
today i bought a 95 e420
it has the same exact problem
i as a mechanic realized it is the wire harness that is bad
you should start with the engine wire harness
 

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Discussion Starter #7 (Edited)
Guys , sorry I have missed your posts. I have not checked the board lately , or my email.
Well, I finally got around to changing the plugs, and fuel filter. I also cleaned the MAF sensor, and breaking a vaccum line in the process. I still have to replace that (thinking of going with rubber hose instead).
This hasent completely fixed the issue, although it seems to not happen as frequently as it had before.


I recently had my front passenger side wheel bearing replaced (no time to do it) at local shop, and wanted to have them inspect it. However, the emissions were too high, and they could not perform the inspection. They have no way of testing it, and I will have to take it to a mercedes dealership for a proper diagnosis. I'll be fixing the vaccum line this week (have it plugged now which fixed the erratic idle) to see if that will help anything.

If it is in fact a wiring harness issue, will this show up on a scanner? My thoughts are wiring harness,dist and/or coils ,O2's , or plugged cat/s.

BTW, I don't have ASR, so I know that isnt an issue.

One of the deals I got when i bought the car is they guaranteed to pass inspection. There is no way I am giving this car up though :D
 
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