OM606 reliability? - PeachParts Mercedes-Benz Forum

777funk · #1 05-31-2017, 10:38 PM

I've had plenty of 617s and a 602 and 603. I enjoyed all of them and the fact that the car would run without the battery connected. Are there major issues with the newer 606s? Any years to avoid? Is it possible to run them with a cable instead of drive by wire?

VW1300 · #2 05-31-2017, 11:07 PM

Not sure about the '95 but the '96-'99s are definitely drive by wire only.

My 606 has been fine, 239K miles and counting. There are people here more knowledgeable than me but my impression is that reliability is good provided you keep up with maintenance.

777funk · #3 05-31-2017, 11:17 PM

I worry about MB electronics. I've heard too many stories about flaky transmission and engine controls. I've experienced it first hand in some cases and I know I've had few MBs where the cruise or other luxury feature electronics actually worked. This makes me nervous to trust MB to electronics that will contribute to engine reliability.

jake12tech · #4 06-01-2017, 12:35 AM

Nope no reason to avoid an OM606. I owned four and have three of those still. Excellent engines in the w210. The electronics are 90% of the time reliable. I've never had any issues. Sometimes you have to replace the K40 relay once when you own the car cause they seem to go bad sometimes. Not a big deal. I haven't had it yet, but I've replaced them on other w210s.

They tend to leak fuel at the delivery valves like the other om60x motors, and the plastic fuel lines need to be replaced every few years as well or will start leaking. Glow plugs require extra work to do. Read a thread from member packerfan, I walked him through the glow plug removal process without breaking any glow plugs using air tools. That's the thing you will hear around here people complaining about is the glow plugs. But they aren't a big deal.

tjts1 · #5 06-01-2017, 12:43 AM

For what it's worth my 97 om606 is in the midst of a 1500 mile road trip and all the electronics work. It throws the occasional p0715 code for the shut off valve but it also clears on its own after a few cycles and the electronic 722.6 is smooth as **** from a ducks ass. It's the perfect road trip car.

torsionbar · #6 06-01-2017, 01:07 AM

Mechanically the 606 is bulletproof. As others have mentioned, it's the electronics that occasionally misbehave- but it's so well documented and understood at the hobbyist level now, that there isn't much you can possibly run into that others haven't already found a solution for. Owning an OBD2 reader is a must. Even better if you have one of the more advanced ones that does MB specific transmission, airbag, etc.

The w210 body is known for weak paint, so rust is a potential issue. Inspect the body thoroughly, and walk away if it looks like the rust has set in. The front spring perches are known to break off resulting in a costly repair, if their mounting points have begun to rust.

I've owned a non-turbo 606 for 10 years, and a turbo 606 for a year, and I really like them. They offer modern creature comforts, and they're not difficult to work on- oodles of DIY info on the web about these models.

PS. in Finland, they swap the electronic 606 IP for a mechanical 603 IP, and tune the crap out of it. They're getting 500+ horsepower from a 606 with bolt-on mods. Amazing stuff, and a testament to the durability of the 606 internals.

777funk · #7 06-01-2017, 07:28 AM

I read of a recent thread poster who said he couldn't get the 98 electronic control for the transmission to quit acting up after trying many things. He said he'd never own another MB after owning 4 (mostly mechanicals previously).

It seems like the newer 606 equipped cars can leave you stranded. I considered one that would not start unless the stop solenoid was jumped and at that wouldn't drive.

This is what makes me nervous.

jay_bob · #8 06-01-2017, 07:28 AM

One very important point about diagnostics on a W210.

This was the first model MB designed with OBDII and as such does not have a full implementation like on later cars.

Only the engine controller and transmission controller are accessible through the OBDII connector. They use the older ISO9141 protocol so make sure your reader supports this.

Due to the regulations in force at the time, only the emissions related codes are passed through the OBDII port from the ECU. A limited subset of transmission codes are also passed. The transmission fault codes are distilled down to a couple generic OBDII codes.

The remaining electronic modules on the car are only wired to the 38 pin diagnostic port under the hood in the left side fuse/relay/SAM box. Each module gets a dedicated pin and communicates via single wire serial in proprietary MB format.

The air bags, climate, or any other body electronic function cannot be accessed via the OBDII port with any tool on the market. The wiring simply does not exist from point A to point B.

In order to diagnose anything else besides engine fault codes and the limited transmission codes requires proprietary MB tools.

There are two devices that work with this vehicle:
- the HHT which is a dedicated tool that plugs into the 38 pin port. If you can find one of these they are often over $1000 and will only work with the 210 (and probably the 202 and a few other related models from that era).

Note that the 38 pin port used on the latest gas powered W124s is the same physical connector but the pinout is different. The modules use simple blink diagnostics that can be accessed with a simple blink check LED, resistor, and pushbutton.

The other tool that can be used on the 38 pin connector is the Xentry system. These are a dealer only tool. However the enterprising Chinese have figured out how to bootleg these and a kit that goes for $750-1500 on EBay can be found.

You can also use a Bluetooth OBDII dongle, an Android device, and the Torque app to get real time data. The data set is very limited but the parameter you need to fix the problem may well be available.

My diagnostic tools for the W210 are a cheap Autel MaxiScan 300 that can be found on the big online book store for about $20, and a Foseal Bluetooth dongle (also on the book store for about $15) and a cheap Samsung Galaxy 3 Android tablet that's about 5 years old we got for an incentive to go back to cable tv.

777funk · #9 06-02-2017, 07:40 AM

Went and looked at a 96 yesterday. I could smell unburned diesel in the exhaust while driving. The rocker panels were rusted through. The wheel well under the hood had a big rust hole in it. There was paint bubbling throughout. The power was ok for a NA diesel. I used to think these held up better than Fords of the same age... not sure about the W210. I'd say a 96 Taurus might be a better car. I owned a 98 Taurus wagon up to a couple years ago that was way cleaner as far as rust than this car was.

pimpernell · #10 06-02-2017, 08:59 AM

Quote:

Originally Posted by 777funk

Went and looked at a 96 yesterday. I could smell unburned diesel in the exhaust while driving. The rocker panels were rusted through. The wheel well under the hood had a big rust hole in it. There was paint bubbling throughout. The power was ok for a NA diesel. I used to think these held up better than Fords of the same age... not sure about the W210. I'd say a 96 Taurus might be a better car. I owned a 98 Taurus wagon up to a couple years ago that was way cleaner as far as rust than this car was.

The E300d series have two MAJOR problems: Spring perches, and glow plugs getting broken off in the head. I had a 96, loved the car, ran great and was a great ride. Parked the car in front of the house in the evening, woke up the next morning to find that the passenger side spring perch had failed, breaking the spring, and leaving the front fender on top of the front tire. A week prior to that, the car was up on a lift, and the perches look fine, with no sign of rust. If I had been doing 70-80 mph I would possibly have been killed without a doubt. Unless you can find a pristine vehicle never driven on salted roads, I would stay away from this particular model.

tjts1 · #11 06-02-2017, 10:52 AM

Yeah I wouldn't own one of these that's lived in the rust belt. That's just asking for trouble.

The GP replacement issue is due to the fact that people are using the wrong procedure. Remove the intake manifold, start the engine, bring it to operating temperature, shut it off and immediately hit the GPs with the impact gun. They'll come out intact. Trying to remove them from a cold cylinder head is just asking for trouble.

nelbur · #12 06-02-2017, 08:59 PM

Quote:

Originally Posted by tjts1

The GP replacement issue is due to the fact that people are using the wrong procedure. Remove the intake manifold, start the engine, bring it to operating temperature, shut it off and immediately hit the GPs with the impact gun. They'll come out intact. Trying to remove them from a cold cylinder head is just asking for trouble.

Do you use a torque stick, or any other technique to avoid high enough torque to break off a really stuck plug?

jake12tech · #13 06-02-2017, 10:09 PM

Quote:

Originally Posted by tjts1

Yeah I wouldn't own one of these that's lived in the rust belt. That's just asking for trouble.

The GP replacement issue is due to the fact that people are using the wrong procedure. Remove the intake manifold, start the engine, bring it to operating temperature, shut it off and immediately hit the GPs with the impact gun. They'll come out intact. Trying to remove them from a cold cylinder head is just asking for trouble.

I found out the same technique for myself and walked a forum member thru the process... this is 100% the only way to remove glow plugs off the om606. It's the design of the plug and chamber as well that causes the breakage of the plug. Plus the fact no one knows how glow plugs work or the advantages of aluminum.

As for the rust everyone is saying... It's a matter of care taken from the original owner. These cars have been around for 20 years and held up that's pretty good. If you don't clean your cars in winter and clean the undercarriage, expect rust. What else did you think would happen?

I've never had serious structural rust on w210s. My '98 was the car that required the most rust repair and it's cause it wasn't taken care of by the owner. I welded arches and sections of both rockers in. Then on the other hand, my 99 with 433k has barely any rust on it and was cleaned and detailed religiously. Both northern cars from jersey

tjts1 · #14 06-03-2017, 06:03 AM

Quote:

Originally Posted by nelbur

Do you use a torque stick, or any other technique to avoid high enough torque to break off a really stuck plug?

No. The plugs are only really stuck when the aluminum head is cold and tight around the plug. When the head is hot it expands and loosens t's grip on the plug. An impact gun can apply a very high torque but for a very short period of time. It's the repeating short impacts that help loosen the whole plug without breaking it. I think on a cold engine an impact gun can damage the plugs but I removed all 6 without issue with it hot. I got the idea from this video.
http://youtu.be/E5ztQ5JetUM

777funk · #15 06-03-2017, 10:41 PM

I've read the IP can be controlled with a PWM signal... that makes me think it might be easy to say bye bye to the computer. Any Arduino can program a PWM output that can be varied with an input into a microcontroller for about $20 in resources.

The later model transmissions however would be more of a chore to sort through in DIY programing. Then again, they're probably just like everything else with solenoids. MB was late to the game with electronic transmission controls.

I don't trust MBs electronics. Too bad they couldn't have stayed mechanical for a longer period.

How are the VW TDis? Mechanical engines on the early generations I'd assume? I'd guess the 05 and later models must be electronic control.