1995 E320 Wagon stubbling, rough running.

[DinNC]

Hello all, I hope everyone is well....

I am having some issues with my 1995 E320. A few weeks ago I replaced the air filter, plugs, and the connections from the coil packs. I noticed that I have three different coil packs, and I believe I put Bosch Platinum plugs in, which I understand the M104s do not like. Right after I did those things, the car would have an occasional misfire. I checked the connections, and one was a bit questionable, so I re-connected and it got better. This morning when my wife went to drive it, it started like very rough. She turned it off, then back on after calling me, and it was better, but not great. It seemed to smooth out after it got warm. The car was parked with its nose down hill( I know this sometimes comes up with the diesels). When I got home I went out to look at it, turned it on, all seemed fine,and gave it some throttle. at about 4000 RPMs(a little under), it acts like a rev limiter is kicking in. It stumbles pretty bad. My CE has been on for a bit with codes 6 and 12. Also the wiring harness has been done. I am stumped, is this a throttle issue, an ignition issue, and fuel issue? Due to the skip, I am thinking coil packs, but the stumbling at 4k has me perplexed(mass air?). PLEASE point me in a direction! The car only has 140k on the clock.

[DinNC]

OK, I am wearing myself out thinking about this....when in traffic the car temp will climb above halfway, seems like the fans take a while to cut on, I didnt rev it past the stumble, so I dont know if it clears out or not....and what the hell is an OVP?

[Arthur Dalton]

Are you talking 4K rev limit in N or P ???

[macdrone]

You dont have an OVP your car is too new. Check the cap and rotor for cracks moisture and buildup. Put the right plugs in Bosch F8DC4's, they are non resistor plugs copper core. They are the closest thing you can get to the right plug. Overseas uses an even hotter plug but cant seem to get them here in the states so i am told.

I would check you A/C charge and/or the sensor as that kicks your fans on low speed.

Coil paks are a really good idea to replace. I am sure they have been on there since you have owned the car, my cars were original when I got them. Plastic covers just kinda keep them out of sight out of mind.

Might check fuel pump/pumps and the filter and check valve just in case as it could be pressure related. Run some chevron through they use a little more detergent in the gas.

Your EHA/ETA could be an issue as our cars are "fly by wire" and its all electrical. If you go to benzworld.com and look up rewiring them youll see they suffer from the same wiring issues as the wiring harnesses.

Good luck hope that helps, tried to go cheap to expensive; small to big deal.

[Arthur Dalton]

< >

Wow , lot's of Incorrect info on this one , too..............

1- Not only does this chassis have an OVP, it has the infamously troublesome one that was Factory changed from part 000-540-52-45 to 000-540-67-45.
A '95 124.092 E320 without an OVP would be wishful thinking......

http://catalog.peachparts.com/ShopByVehicle.epc?q=1995-Mercedes--Benz-E3--0--Wagon-Body--Electrical&yearid=1995%40%401995&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6392%3ABT%7C6%3AMBC%7C1522%3AED%7C10000022%40%40E320+Wagon&catid=241959%40%40Body+Electrical&subcatid=242003@@Overload+Relay&mode=PA

If you have the Original OVP part#, change it to the Modified part #, regardless.

2- This chassis has DIS Ignition system, so it has NO rotors or caps. It is Distributorless Ignition.

3= You do not have EHA system...this car is HFM/SFI full electronic.

Which is exactly why the OVP is suspect.
It is located behind panel to the rear of the Battery. Tall, aluminum relay w/fuse on top. Part# is on the side..if it is made by Siemens, it is the faulty one.
And get rid of the Plats . Never use Plats in a 104 Waste Spark Ignition system.

Don't even bother looking for caps/rotors cuz there are none, but you will find an OVP right where I posted.

You also want to get the existing codes from pins 8 [ HFM-N3/4 module] and pins 14 [ Elecronic Actuator module]
The codes you have posted are Emmissions codes and the actual codes you want now are in the Engine Management ECU. The codes you list are only CE lamp activation/emmissions codes from the DM -N/59 module.

On the 4K limit, that is normal default torque converter RPM protection in N or P gear selection...so, an answer to that question/post is required for proper diagnosis. You can verify that by driving >8MPH and putting into N ..the 4K limiter default will then be over-ridden and higher RPMs attainable.
Back to N or P at standstill and the 4K limit will default again. Normal.

Go here :
This will tell you how to get the correct codes and the charts for each module.

E320 16 PIN DTC Charts inc. pin 8, pin 14

[DinNC]

Originally Posted by Arthur Dalton

Are you talking 4K rev limit in N or P ???

DUOH!!!

[DinNC]

Originally Posted by Arthur Dalton

< >

Wow , lot's of Incorrect info on this one , too..............

1- Not only does this chassis have an OVP, it has the infamously troublesome one that was Factory changed from part 000-540-52-45 to 000-540-67-45.
A '95 124.092 E320 without an OVP would be wishful thinking......

http://catalog.peachparts.com/ShopByVehicle.epc?q=1995-Mercedes--Benz-E3--0--Wagon-Body--Electrical&yearid=1995%40%401995&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6392%3ABT%7C6%3AMBC%7C1522%3AED%7C10000022%40%40E320+Wagon&catid=241959%40%40Body+Electrical&subcatid=242003@@Overload+Relay&mode=PA

If you have the Original OVP part#, change it to the Modified part #, regardless.

2- This chassis has DIS Ignition system, so it has NO rotors or caps. It is Distributorless Ignition.

3= You do not have EHA system...this car is HFM/SFI full electronic.

Which is exactly why the OVP is suspect.
It is located behind panel to the rear of the Battery. Tall, aluminum relay w/fuse on top. Part# is on the side..if it is made by Siemens, it is the faulty one.
And get rid of the Plats . Never use Plats in a 104 Waste Spark Ignition system.

Don't even bother looking for caps/rotors cuz there are none, but you will find an OVP right where I posted.

You also want to get the existing codes from pins 8 [ HFM-N3/4 module] and pins 14 [ Elecronic Actuator module]
The codes you have posted are Emmissions codes and the actual codes you want now are in the Engine Management ECU. The codes you list are only CE lamp activation/emmissions codes from the DM -N/59 module.

On the 4K limit, that is normal default torque converter RPM protection in N or P gear selection...so, an answer to that question/post is required for proper diagnosis. You can verify that by driving >8MPH and putting into N ..the 4K limiter default will then be over-ridden and higher RPMs attainable.
Back to N or P at standstill and the 4K limit will default again. Normal.

Go here :
This will tell you how to get the correct codes and the charts for each module.

E320 16 PIN DTC Charts inc. pin 8, pin 14

AH-HA! I have some direction...and I am off! I will check the OVP first, then order coil packs and correct plugs. I will work on building a code reader...thanks a million, I will keep posting as I learn more.

[Arthur Dalton]

Don't get coil paks until you get the codes from Pin 8 of HFM module...that will tell you if all/any of the coil paks are NG..that is the reason I am sending you to HFM module for Engine Management codes...see?

[DinNC]

Originally Posted by Arthur Dalton

Don't get coil paks until you get the codes from Pin 8 of HFM module...that will tell you if all/any of the coil paks are NG..that is the reason I am sending you to HFM module for Engine Management codes...see?

I see, said the wise man....

[DinNC]

Code reader seems simple enough....I will be stopping by Radio Shack shortly..wish me luck

[Arthur Dalton]

Very Basic...


A good chassis is an empty 35 MM film container...easy to poke a couple of holes in to mount the sw and exit the leads.

Only trick is read the instructions on the LED b/c they are polarity sensitive..if it does not work, you most likely have the LED leads reversed...common mistake.
When the tool is assembled, an easy verification test is to simply put the red + and black- across a car battery and press the switch...if the led lights , you are good to go. If No, yoo are reversed on Led lead/ wiring.......

[DinNC]

Originally Posted by Arthur Dalton

Very Basic...


A good chassis is an empty 35 MM film container...easy to poke a couple of holes in to mount the sw and exit the leads.

Only trick is read the instructions on the LED b/c they are polarity sensitive..if it does not work, you most likely have the LED leads reversed...common mistake.
When the tool is assembled, an easy verification test is to simply put the red + and black- across a car battery and press the switch...if the led lights , you are good to go. If No, yoo are reversed on Led lead/ wiring.......

If you were anywhere near me, I would buy you a beer!

[Arthur Dalton]

Where were all you Beer Buyers whan I used to Drink ????

[DinNC]

Originally Posted by Arthur Dalton

Where were all you Beer Buyers whan I used to Drink ????

Good for you. Well on your way from NH to FL, or vice versa, stop by for a milkshake I havent made it to Radio Shack yet....the damn car seems to be running fine now(KW)

[Arthur Dalton]

OVP are intermittant, so I would at least see if that one has been upgraded to the new part#..if No, change it anyway, cuz it will fail. [ and possibly leave you standed in Baltimore................... ]