Hi, long time lurker here but asking for help, now. I have a 2000 ML320 that has basically been trouble free. It has 89,000 miles and has suddenly started running really bad. No warning, it just happened. The CEL came on and the engine started running really rough, like it was not running on all six cylinders. I drove the car home and could only achieve about 40 mph in 2nd gear, floored. I hooked up a OBD-II reader and got P0100, P0110, P0300, 301, 302, 303 and 306. I replaced the MAF sensor. I cleared the codes and started the car again. Immediately got a P0302. I swapped the ignition coil from cyl 1 and cyl 2. I cleared the codes again and started the engine, P0301. I bought a new coil pack and replaced the one on cyl 1. No change, the car still runs bad. If I try to drive the car, I get P030* codes on just about all of the cylinders. Plugs are original but look clean and are gapped right. Wires are good. Right Cat was replaced about 8 months ago. I'm stumpped and looking for advise. Help please......

Plugged cat?

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Ric
Ann Arbor
2000 ML320, 172k

If you think education is expensive, try ignorance.

I would try replacing the plugs. My car has 96,000 miles and all of the sudden it started running like crap one day about 1000 miles ago. I looked at the plugs and they looked alright, but I replaced them with NGK Iridium IX (or something like that name) and the car runs muuuuuch better. one wire was bad on my car so I just opted to pay the $190 and replace all the wires. They just arrived yesterday so I have not installed them yet, but it should fix all rough running problems.

at 89,000 miles your car is due for a plug change, so I would try that first and see how it goes.

Thanks for the replies. I gave up on the car and sent it to the dealer. I actually had to have it towed because it would not move under its own power. I talked to the dealer today. They're not sure what is wrong with it but said that they have to replece the plugs and wires to rule them out as a problem.

I guess I cannot complain, this is the first repair that I had to pay for. I know that others have had issues with their ML's but ours has been a good car so far. When I hear what the solution was, I will post it here so that others here may benefit in the future.

Last I was at the dealer they wanted $500 to replace the plugs, not including the wires....OUCH....(dealer in Ann Arbor, Michigan)

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Ric
Ann Arbor
2000 ML320, 172k

If you think education is expensive, try ignorance.

It was the MAF. The new one that I put on was apparently bad. Dealer replaced the plugs, wires and MAF. All together, plus towing was $1800. I'm okay with that, I guess, but my wife was rather shocked by the repair cost. I can usually fix anything so we're not used to shelling out that kind of money for auto repairs. Well, live and learn...

I'm curious about your purchase of a 'new' MAF and it being bad?? Did you get it on-line or from a dealer?

I am struggling with a similar issue, codes P0170 and PO173. I've purchased a supposedly 'new' sensor off e-bay. But I took the old one out, cleaned it with brake cleaner, and after a couple of starts the CEL went out. So I will hold onto the recently purchased sensor, but am concerned that it may be 'bad' but I would never know.

Joe

I purchased a new one from an auto parts store. It appeared that it was actually a remanufactured one, but it was still a Bosch like the original one. Both the orginal one and the one that I purchased were clean inside and looked identical. The dealer then installed a new MB part and the car suddenly started running right.

If you suspect that the one you purchased is bad, install it in the car and try it out. Worst case is that the car runs bad and the MIL comes on. They are real easy to swap out.

One more thing, I never saw any P017* codes, mostly just misfires and a P0100/0110. Oh, and my car ran so bad that it would not even move under its own power.

Good luck, JML!

included in your $1000 bill was a crankshaft position sensor,

I bought one for $70 when miine had about 90,000 miles. cured it.

you also may need to clean out the EGR Tube. mine was plugged.


did you get iit fiixed ?

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Steve Danville
what i did myself.
CPS
rear shocks
MAS x 3.
SparkPlugs (twice)
Fuel pump & Filter
Window switch
replaced both failed horns with Honda horns.
Cleaned ERG Tube
Oil changes
Oil consumption Fix
Brake Pads
A/C Recharge
Anti-Freeze change X 2.
Front Shocks. Monroe. $90
Mercedes Warrenty Work:
Harmonic balancer,power steering clamp. Cat converters.Drive Shaft Bearing.s
Replaced Outer Lower Tie Rods and front lower ball joints at 156,000 miles

I had the exact same problem with my 2001 ML. I purchased the MAF from Ebay, but it was a bosch brand new (sealed). Took it to the dealer after scratching my head and trying everything else. Much to my chagrin, and theirs, when they replaced the MAF, it started running like a champ!

Lesson: Never assume the MAF you just purchased is good (and sometimes you can't fix everything)