OM606- Good Engine?
 

I'm now seriously considering a OM606 non-turbo 3 Litre wagon and was wandering what the 'driveability' is like with this engine. I'm used to peppy small displacement turbocharged 4-bangers.

Any known problems? Do they blow head-gaskets like the 6-cyl gassers etc?

They are a very good engine and not to bad to fix. Get a turbo if you can the extra power is nice, also their is more room in the engine bay with a turbo believe it or not.

unfortunately there was no turbo 606 in the uk in the 124 chassis i'm looking at, due to the right-hand drive. I don't like/can't afford(!) any of the models post 124.
I guess i'll just have to test drive one and see how it is.

Hi, we got a 1995 E300D non turbo OM606, 166000Km on it. We are the second owner and looking back at all the records there was drivetrain problems at all. The car had little stuff like bad sunroof switch and burned out bulbs. Ohh, and I think the oil sender unit was replaced.

On the other hand if you need new glow plugs, the intake manifold has to be removed. Just before we bought the car, the previous owner installed new glow plugs at 158000km, it cost him $1200 canadian. Other than that it seems like they are durable engines. I know of some mercedesshop fellows that have some high km on the engine. One member, which unfortunately I forgot his screenname has about 500,000 km on the OM606!

Would that be me by any chance?
 

I’m not sure how one defines “good”, but I’d have to say that with 338,000 miles on her, mine is still amazingly “good”. Recently did the head gasket & valves; you could still see the factory honing marks in the bores. This engine only had minimal servicing by the PO including oil changes at 7,500-mile intervals. (Per factory recommendations – ugh.) It was primarily all freeway mileage that accumulated on the car however.

If you like your small displacement turbo four-bangers, then you will find similarity to this engines’ driving characteristics, at least as far as you can compare a diesel to a gas burner. Not a lot of low-end torque. It likes to rev (again, it’s relative – it likes to rev compared to other diesels) in order to make power. Where my 617 has more low & midrange torque, that engine runs out of breath where this one starts opening up it’s lungs. It just loves to dive for 5000 RPM’s all day long. And talk about smoooooth… Yes, it’s a sweet engine. And if it’s attached to a 124, it’s a sweeeet package.

The only thing better would be to find a wrecked 98 or 99 E300D & Frankenstein the turbo engine & trans into my 124 – now that would be fun! (Provided I could eliminate all the OBD-2 garbage from it, that is...)

I like the OM606 motor. I think it was one of the first 4 valve per cylinder diesel engines. The motor revvs nicely to around 5,000 rpms and sounds great. Good power and torque. Good mileage. I have 137K miles on my car, bought it with 85K miles...put 50K miles on it in 2 1/2 years.

Shifting Points
 

Hello,

Since we are on the RPM subject, I was wondering at what RPM do you guys let your tranny shift.


From a standstill, if I let the car shift from 2nd(2nd gear start) to 3rd gear at about 2000-2200 rpm, the OM606 doesn't seem to pull that strong . I read in the manual that the peak torque is made at 2600RPM. Now if step on it a little bit more from a standstill, it pulls nice. The tranny shifts at about 3200RPM. I guess it all makes sense, following the torque curve. It's a DOHC so it probably likes to rev higher. However, I rarely let the tranny shift at 4500-5200 RPM, thinking that I am stressing the engine

Anyways I was wondering about your driving/shifting habits in the W124 OM606.

Interesting question. Most of the time driving around town I don't pay much attention to the shift points. But if I'm merging on to the highway I floor it and hold it...motor will rev to around 5K in 1st, 2nd, 3rd. Other times I'll manually shift the trans.

re: stressing the engine. From everything I've read these cars need an italian tune up from time to time.

Yes, I also hear about the italian tune up! I guess a good highway run should be able to clean out the crud from the engine!

The tach has no redline, why is that? Is the redline around 6000 RPM, the end of the tach?

I just wanted to make sure, these cars start in 2nd gear right?

Ohh, another thing I noticed, the 5 spd tranny in an S320 will have the engine hover at 1500rpm while the car travels 70km/h. THe 4 spd tranny, 60km/h=1500 rpm

Not sure why there isn't a redline...but I think if it was marked it would be lower than 6K. The owner's manual might say.

The speedo is marked for max speed in gears by numbers for 1, 2, and 3. If you floor it you'll see the trans upshift right around those numbers on the speedo. I don't think shifting manual is any faster but allows you to prevent an upshift too early if you're not flooring it.

No, I don't think these cars start in 2nd.

Redline should be 5250. Yes, in 24 valve non-turbo form.