Should I be scared of a W109 with the M189 engine?

[billhard]

I have come across a 1967 300SEL for sale locally and really like the looks of the car. My only experience to date has been with the 280SE 4.5 I now own, so how shocked will I be with regards to cost and availability of parts? Is the M189 wading into the deep end of the vintage mercedes pool?


Any of your thoughts, encouragement or words of warning would be greatly appreciated.

Bill

[rbtoj]

I don't have any experience with this engine, however I don't imagine it will be much different from other d-jetronic engines of the period.

[CTD]

Make sure there are no cracks in the distributor cap.

[Tony H]

I think it is a very expensive engine and car to maintain with it's rare engine and air suspension-much more than the value of the car. A member on the MBCA forum/featured in the STAR magazine installed a 5.6 in his and converted the air suspension to a modern system.

[berfinroy]

I agree with Tony H that the 189 engine can be very expensive to repair if its fundamentals are not sound. You should have an experienced mechanic thoroughly check it out.
As for the air suspension system, it, too, can be expensive to make right, but is amazing and durable once sorted out. There are several sources for rebuilding leaking control valves (one rear, two up front plus the main distribution valve...), which is the most common problem.
Rare car. Only 2369 made world wide. How many sound running examples are left now? Probably a handful at best. Remember, this is the same basic engine that powered the legendary 300SL.
It has mechanical fuel injection.

[ScooterABC]

Originally Posted by billhard

I have come across a 1967 300SEL for sale locally and really like the looks of the car. How shocked will I be with regards to cost and availability of parts? Is the M189 wading into the deep end of the vintage mercedes pool?

Any of your thoughts, encouragement or words of warning would be greatly appreciated.

This is not something I would purchase casually. The air suspension issues are well-documented. It can all be sorted out and could set you back $10,000 to do so, or maybe just $3000. Or maybe it's perfect as it is.

Then the M189 - it's a wonderful engine and highly reliable. Having said that, there are issues and if you have an issue it is prohibitively expensive to repair. I think Metric Motors wants ~$40k to rebuild the engine IF they can get the parts. The generator-water pump combination is unique to this and parts are not available. The heat exchanger on the driver side of the engine tends to get bolts rusted in place, cooling lines rusted, and contaminate the water with oil. If that's the case then fixing it involves pulling the engine unless you get really lucky and are able to get to all the bolts by removing other stuff. Then you have to have a new one fabricated. (Or bypass the whole thing and come up with a different oil cooler)

I purchased a rust-free 1965 300SE lang (like the car you are looking at except a Fintail). I bought it before I knew much about the engine, and I spent two years cleaning the fuel system and injectors and pump to the point where now the engine will start. I _do_ have oil/water contamination and I'm probably not going to address that, as my interest in working on the car is diminishing. The only reason I bought the car is because it was a LWB fintail. If it were a W108/W109 I wouldn't have touched it.

So I guess the questions are:
1. What kind of condition is it in today?
2. Do you really want an air suspension car?
3. Is it totally rust-free?

If it's in anything other than good driver condition I would look for another. Or get a 4.5 or 6.3. Or even a M130. The nice thing about the W109/W112 is the better interior, increase in wood and trim, etc. The not nice thing about the M189 is it's expensive to fix. The not nice thing about air suspension is that it's expensive to fix if it needs it.

that's my 2 cents.

[berfinroy]

With regard toScooterABC's comment concerning the cost of refurbishing a W109 air suspension, I submit that the cost is likely to be a lot closer to $3000, $5000 tops, and that's if you do nothing--like removing and reinstalling air control valves--yourself. The air bags themselves, which cost around $400 each, are rarely the problem, even if they have superficial exterior cracks.
Martin Werminhausen's site <600airsuspension.com> is probably the best resource for everything you need to know about these systems.
As I said before, once sorted they are durable and produce a ride that is remarkable even by today's luxury car standards. Only Citroen's revolutionary hydro pneumatic system developen for DS series cars in 1955 is comparable.

[billhard]

Thank you all for the opinions it's much appreciated. I am clear on the perils of the air suspension, but the motor is still an unknown to me. From what you all are saying it seems like a great motor, very reliable, but if it breaks you are screwed. I currently live with a Porsche 928GTS which makes me very familiar with being in that situation. Here are a few questions I still have:

Does the M189 have an impact on the car's value either good or bad?

This car being a 1967 seems to have a number of switches and controls that are different from the later 109's. For example the interior lights, air suspension raise control to name just two. Were these from the earlier W112 cars or are they specific to this car?

[ScooterABC]

The air bags are cheap. The valves I was _thinking_ are under $1000 but over $500 each to rebuild - 3 for the car plus one main one makes 4. The compressor and tank are usually fine, but not cheap if they are not fine. If the lines are bad then ????

Regarding your questions on the M189 impact on car value - I don't think it improves things because it adds anxiety. Particularly if there are other engines (3.5, 4.5, 6.3) available. On the early M189 cars the option was a smaller 6 (220 MFI) which was less power. Also, the purity and heritage of the car being original and having the "special" engine isn't that important since the car itself isn't in high demand. If it were a cabriolet then it would be a different story, and I think having the "cool" engine would be a plus. But the "cool" engine in this car would be the 6.3 not the M189.

The air suspension switched from two settings to three settings probably around the time of your car. I think the settings are Lock and Normal, and then Lock, Normal, High. It is more complicated and expensive to rebuild the EARLY valves (like my 1965 has and maybe the 1967 has). I'm not aware of other controls being different. The light switch should be the same. If it's a 6.3 it would have a tach, maybe with a 3.5. Not with a 4.5 or the 6 cylinder engines. In that case the tach goes in the hole where the clock is, and a rectangular clock (like on a fintail) goes on the level where the switches are, I think to the left of the steering wheel.

Early W108/W109 dome lights are different from later ones, but it isn't related to the 108 vs. 109. Later cars are more likely to have rear reading lights on the C pillar, but it was an option in both the SWB and LWB cars, pretty much always on the US-spec LWB cars after 1970 or so.

[strelnik]

Originally Posted by berfinroy

With regard toScooterABC's comment concerning the cost of refurbishing a W109 air suspension, I submit that the cost is likely to be a lot closer to $3000, $5000 tops, and that's if you do nothing--like removing and reinstalling air control valves--yourself. The air bags themselves, which cost around $400 each, are rarely the problem, even if they have superficial exterior cracks.
Martin Werminhausen's site <600airsuspension.com> is probably the best resource for everything you need to know about these systems.
As I said before, once sorted they are durable and produce a ride that is remarkable even by today's luxury car standards. Only Citroen's revolutionary hydro pneumatic system developen for DS series cars in 1955 is comparable.

I agree with you completely about the Cits, but I am biased, since I own several.


I have owned two 189s and found the biggest problem to be past negligence, causing irreparable damage or requiring replacement of highly expensive worn parts.


If you can examine the engine at length and the main workings seem good, you might get away with re-ringing and replacement of all lower-end bearings. Just my two cents.


And yes, check the distributor and the Bosch injection pump innards, especially the cam.

[alabbasi]

Originally Posted by rbtoj

I don't have any experience with this engine, however I don't imagine it will be much different from other d-jetronic engines of the period.

Very different

[ScooterABC]

Originally Posted by rbtoj

I don't have any experience with this engine, however I don't imagine it will be much different from other d-jetronic engines of the period.

The fuel system is nothing like the d-jetronic systems. It is basically the same as the mechanical fuel injection system found in the other 6 cylinder cars from the 60s and early 70s, and the 6.3 V8.

[billhard]

Thanks for all the input, unfortunately whilst I was hand wringing a gentleman from the Philippines bought the car. I called yesterday to set up a PPI and was given the news. It seems the car sold for $26500, about what I was going to offer, the ask was $32K. I am upset to have acted so slowly but live and learn I suppose. Here is a link to the car if you all are interested.

Thank you all again, at least I'll be ready for the next car. I suppose my 1984 Wanderlodge still has plenty of projects that need tackling to keep me busy.

Cheers!

[ScooterABC]

Originally Posted by billhard

Thanks for all the input, unfortunately whilst I was hand wringing a gentleman from the Philippines bought the car. I called yesterday to set up a PPI and was given the news. It seems the car sold for $26500, about what I was going to offer, the ask was $32K. I am upset to have acted so slowly but live and learn I suppose. Here is a link to the car if you all are interested. !

You didn't act slowly. You did research as quickly as possible and got some good feedback on something you didn't know much about. In this case it at least looks like it was a really nice car. The guy from the Phillippines didn't get an inspection. Who knows what surprises he bought. You did well.