Hey folks. This is my first MB and diesel. Instead of continuing to throw money at the wrong things, I wanted to run some things by you to get a better feel of how my car's aging and to see what's "normal" and/or acceptable and what's not.

1. Mileage: 170k. 100k on new short block replaced in 1979.

2. Compression: 290-310 psi. Jumps to 320 across all 4 when "wet".

3. Valves adjusted to spec.

4. New timing chain rolled in. Uncertain as to where they adjusted the IP, but I think they left it slightly advanced.

5. Oil consumption: slight. I've put about 1,000 miles on it since summer and there's some decrease in oil level. Some oil loss could have occurred when they rolled in the new chain(?). Regardless, I have some blow by.

6. New fuel filters and performed a diesel purge.

7. Sent Bosch injectors off to be pop tested and adjusted if necessary (they didn't need to be).

8. Starting: warm summer day = no problem. Sometimes doesn't need glowing. Now that winter's setting in (garage temp is 35-40F) - did require 5 glow/start cycles and then the battery went flat on several occasions (diagnosed as dead). After replacing the battery - three 30 second glow/start cycles until it can light off completely and idle on its own. This is without using the block heater. Haven't tried with.

9. Smoking: White smoke at cold idle which goes away when warm and then dark grey smoke when hard on the accelerator or going uphill. Occasional wisps of dark smoke visible at idle when warm, though, all other times there's a noticeable "haze".

10. Power - 0-70mph as indicated on the speedo is about 30 seconds. Looses power quickly going up hills. A local 4 mile grade at 8-9% has me starting at the base going 75mph. It crests doing 50 and with my foot on the floor and passing gear engaged.

11. Fuel economy - Too much fluctuation with repairs, tank drainings, and whatnot to get an accurate feel, but probably 25mph highway on rolling WV hills.


I've also had the the car painted, mounted fresh Bilsteins, and will have new tires going on next week. A stereo will come within the next few months. At the expense of embarrassing myself, I've spent well more in repairs than I paid for the 240 to begin with. But I enjoy it...

Anyway, the MB indie noted some "sticking" in the IP. He also said that the governor bellows had a pin hole. He seemed to think that both of these would contribute to a smoke problem but wasn't concerned about it.

I'd like to have the IP gone through and rebuilt. I'd also like to consider Monark injectors. I think that doing both would help with the smoke/starting/and power issues. But is the expense worth the return at this point?

Given what I listed above, can anyone give me a rough idea of how my engine is doing in terms of aging well/badly and some recommendations on what, if any, work should be done next? I lack the experience and frame of reference and need some pointers.

Thanks!

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1974 240D "Boldie" 170K.- New timing chain/freshly rebuilt IP/replaced valve seals/injectors/upgraded stereo/new Bilsteins with Yokohamas/fresh paint and rocker panels plus lots of welds.

Well if you could pull a used injection pump from a pick and pull really cheap. Take it home and submerge it in diesel fuel in a can with a lid. Just in case your current one becomes really excessivly problamatic at some point. This would not hurt. Easier to find when not required right away usually and cheaper.

Also either test or install a 0-30 pound liquid dampened fuel pressure gauge. In hilly area you want 19 pounds fuel pressure in the base of the injection pump. Make sure this way that you always have good operational fuel pressure.

Twenty five miles per gallon in your hilly area sounds reasonable. You have checked the level flushed and replaced the separate oil supply in the present injector pump?

Thanks for the info, Barry. I haven't focused on fuel pressure but have siphoned out and refilled the IP oil.

I've tried to track down an IP but haven't had success in determining exactly which model I have. I even posted here once with no luck. Regardless, there's no pick and pull remotely close.

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1974 240D "Boldie" 170K.- New timing chain/freshly rebuilt IP/replaced valve seals/injectors/upgraded stereo/new Bilsteins with Yokohamas/fresh paint and rocker panels plus lots of welds.

Bellows hole can cause smoking. Good thread on that here within the last 8 weeks with video of the smoking. Describes the bellows/diaphragm replacement. My recollection is that a new diaphragm is not available.
I'd put in pencil plugs. I don't think the existing relay is compatible with pencil plugs. I'd convert to a Ford starter relay and push button system.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

If you want IP information have a look in the W123 non turbo part of the FSM

Chap 07-001 states

PES 4 M 55 C 320 RS 47 (M) was used in the OM615.912

PES 4 M 50 C 320 RS 14 (M) was used in the OM615.913

You should be able to find the these numbers on the pump - this is the front part of the "IP" - the back part which is a bit bulkier is the governor and that has a different number...

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Thanks for that.

I'm aware of the glow plug conversion but am trying to keep the car as original as possible.

It's not a daily driver so I'm ok with temperamental cold weather starting so long as it's not indicative of something serious.

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1974 240D "Boldie" 170K.- New timing chain/freshly rebuilt IP/replaced valve seals/injectors/upgraded stereo/new Bilsteins with Yokohamas/fresh paint and rocker panels plus lots of welds.

Just so you have a lofty goal, here is a rare example of how these cars are supposed to cold-start, even with the old-style glow plugs:

Mercedes Benz W115 1968 200D first start in almost 6 months - YouTube

In fact, most of the diesels from the 60's to the early 90's with the Bosch mechanical pumps from Mercedes, VW, Toyota, Peugeot, International, Cummins, etc., would all start in one second if everything was perfectly in spec. When I was growing up, my family and many of my friends' families had these diesels and I always marveled that they'd start better than carbureted vehicles, provided you preglowed for about 20 seconds.

Well, that is, down to about freezing. Below that, things would get a little rough and smoky. Below about 10F...good luck starting if you didn't have the block heater plugged in.

My 240D has never started that perfectly except when the engine temp is above 100F. I think I have multiple problems including timing, worn injectors, linkages, valve stem seals, glow plug filaments that aren't putting out their full heat, and that strange little choke-like device in the intake that doesn't work like it should. Not to mention significant blow-by.

Mine always has been taking about 3 seconds to fire and then idled rough, like on 3 cylinders, for about 10 more seconds, and always requires about half throttle (or idle adjuster turned all the way up) during that period or it would stall. After that, it runs great.

This last weekend I had the starting problem you described for the first time. Temperature was about 35 - it took over 5 seconds to start, then immediately died. Had to repeat this two more times with full throttle to keep it running. I was low on fuel though.

Fuel problems are most common so I plan to check the lines & filters first, then go after pump timing, linkages and injectors. I figure that ought to improve things even though I know my compression isn't optimal.

I would say in your case...the same...check filters, o-rings, clamps, and lines to make sure everything is tight. Try diesel from a different station or some fuel additives (see whunters posts about the bad diesel). I had severe nailing for a while which is gone now and I didn't do a thing....so I'm thinking I may have had some imperfect fuel.

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1976 240D "Katja"