Maladjusted valves won't cause slow cranking. Got to be another problem. Are the connections to the starter ok? Sounds like a poor starter or battery to me.

__________________
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 your primary filter darkens quickly, you may have fuel issues, critters living off your diesel. Replacing, replacing, replacing, will help that situation, add some bio-cide, perhaps.

__________________
83 SD

84 CD

thesst - check connections including grounds and main ground
Zerohour3k - check glow plugs

__________________
1981 300TD - SOLD
1981 Euro 300TD 4 sp. parts car
1982 300 SD - SOLD
84 300 TD 4 sp n/a 241K - SOLD

Slow cranking is a good way to not start in winter. Only a couple of factors here. 15w40 could be a bit thick for 30ish temps. 5w40 Mobil1 might help. 50 amps for starter? Is that on a bench or turning the motor over? Sounds way low for spinning a diesel engine. Like they said above, check the condition of the cables/connections from the battery to the starter...hot and ground. Battery should not drop below maybe 10.5 volts when cranking. Even higher voltage is a lot better. If battery and cables are good, starter is next. If you can get one cheap from a boneyard, do it.
If the engine starts but seems to hit and miss with the series style plugs, I would think valves. They make a big difference as they change the compression presure.
My son is driving my '76 300D. He said it has started every morning as long as he let the plugs glow till the light went out (probably 60 seconds!). Not a perfect idle, but I'm sure I need to adjust valves again.
My '86 SDL is sitting outside this week so I guess I get to see how it will start tomorrow-supposed to be the coldest night yet. I just replaced the glow plugs, so they are good. Battery is old and weak. Means I gotta start on first try.

Well, I got my new replacement "pencil" type plugs today. I made jumpers to go between each plug from 10ga wire, and hooked them up via the old connector. I may put in a solenoid relay to handle the current, I'll see if it blows the fuse. I have a spare.

Not too bad of a job, really. I left the hard fuel lines in place, it might be easier if you removed them. This was on a 616 also, a 617 might be hard to get to those center plugs.

If you need the pencil style plugs for a older engine with the loop plugs, they are Bosch #80035.

Car started fine, but it was still warm from running earlier. I let it glow for about 10 seconds. I am excited for shorter glow times!

I will report back once I get to start it cold. Thanks all for your help!

__________________
'79 240D 4 speed manual 105k miles

Well, it got down to about 32F last night, I think. A little frost on the top of the car this morning at 7:45AM. I hopped in, glowed my new plugs for about 30 seconds and cranked. Fired on the second or third revolution and ran pretty good. So far I am satisfied. We'll see how it is once it actually gets cold.

One thing though.... the engine sounded......different, cranking this morning. Maybe a faster crank? Anybody else do this job and notice the same thing?

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'79 240D 4 speed manual 105k miles

We should probably work up a "Sticky" for the check list on this subject. Most of the issues are already noted above. But the main things are:

Battery, battery terminal/ground connections and charging system. Diesels are tough on batteries. Have the battery checked for taking and holding a charge. Hot, humid summers and aging corrosion resistant coatings make for higher resistance connections. Means potential for real voltage drops at the connections, which leads to heating, which leads to even higher resistance. Check the connections by disassembling and wire brushing each contact surface and threads, then put them back together greased with a good assembly grease. Also, make sure the charging system is fully functional - more than 13.6 V with the blower on and the high beams on, at idle.

The oil. I recommend Mobil Delvac 1 all year round, but especially in the winter. My 1975 240D spent 1976 and 1977 in Anchorage, Alaska. Mobil 1 just came out back then, and it was a life saving product for cold winter starts. I "was converted" and have never used dino oils since. When all of Mother Nature's forces are against getting your Diesel to start, leaving an oil in the crankcase that demands another 5% of the starter is going to make the likelihood of success lower. And, since most of us on this site are aware of the need to change oil frequently, we do. The added cost of a good 5W-40 Diesel rated synthetic oil is trivial compared to the trouble of not starting in cold weather at the mall or at work or at home.

Glow plugs. Healthy glow plugs draw current from the battery that is then not available for running the starter so multiple glow cycles are not always welcome - make sure the plugs and controls are in good working order and your battery is strong before doing a multiple glow or longer glow cycle. Unhealthy glow plugs (higher resistance) draw current but never get hot enough to do their job, or, burned out ones just don't work at all. This is another "system" check, involving the fuse, the connections to the glow plugs, and the type of glow plugs. Early models had really poor performance "loop" style plugs, and a similar filament on the dash that drew enough current to actually glow. Bad system, and it was replaced by the newer, parallel glow plugs of the pencil design, that have no visible loop. From all accounts the old style plugs and controls and wiring should be trashed and replaced by the newer systems. I never did this on my old cars, but in retrospect I probably should have. In any case diagnostic testing of the newer, parallel pencil type plugs is much easier than the old, series connected, loop type plugs. In any event, good plugs are a prerequisite to a cold start.

Starter. Check connections and then, if the battery and charging system are sound, the battery connections clean, the oil a decent synthetic selected for winter starts, and the engine is turning over too slowly to start, you may have a bad starter. They get abused in the winter months, and have to work harder in a Diesel anyway. So they fail. Don't be shocked. Also, don't buy rebuilds from random rebuild houses. Rebuilding an electric motor, or alternator, is typically limited to replacing mechanical stuff, and brushes if they are part of the package. Winding checks, at operating temperature, are rare, and rewinds are even harder to find. At most some places will clean the windings with solvents and then dry them and "dip" them to recover the old insulation with a new coat of varnish. This is typically temporary at best. The added varnish keeps heat in and leads to thermal degradation, and the dip is only effective at repairing an insulation weakness if by dipping the starter the defect is covered. Poor starter performance shows up as slower engine rotation and cannot be tolerated in the cold. As the piston compresses the air charge in the cylinder, the air heats up. With a warm engine the air temperature reaches the combustion temperature needed for the Diesel fuel injected. In a cold engine the air around the injection point in our prechamber equipped models is heated by the glow plugs and the added heat of compression makes the temperature high enough to support combustion of the fuel as it is injected. If the engine turns too slowly, the heat of compression is absorbed by the freezing cold block as quickly as it is made and the glow plug turns out to be unable to do the job alone. So, you get a response that could be mistaken or confused with bad glow plugs.

General condition of the engine parts that generate compression, meaning valves and rings/cylinder interfaces and timing. If the valves are closing at the wrong time, you may be pumping a portion of the air on the compression stroke out the intake or the exhaust. So you end up with the wrong volume at the start of the compression stroke, and the wrong final pressure and temperature. This issue is typically a valve lash adjustment and an examination of the timing chain/possible change, away from being fixed. Once you go this far, check injection timing too, and if you have reason to suspect the condition of the injectors, check them as well. Bad injection timing or injectors just means another strike against you when the weather chips are down which is when you can typically least tolerate not starting. These issues, other than valve adjustments are not yearly expenses. They are a once in several tens of thousands of miles needs on an otherwise reasonably well maintained car.

If the valves are leaking, or the ring to cylinder seal is leaking, especially with a weak starter or battery, you end up leaking away too much of the compression stroke to generate enough heat to get a temperature high enough to support igniting the Diesel fuel. The fix here is more involved and costly.

With everything nominal, these cars start reliably in zero degree weather and below without block heaters. It is, after all, cold in Germany in the winter. Munich is at the same latitude as Montreal, as I recall. And, once everything is nominal, keeping it that way is not going to cost an arm and leg. These cars were famous for being taxi cabs in Munich, and the taxicab drivers owned their own cars back in the 1960s and 1970s. So, they were a frugal group of stead MB Diesel customers. Good luck, Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

OK, I still need to check my battery groundings (main ground was good), but I discovered the following:

- Charged battery to 100%, then let it sit overnight connected to car. Checked in the morning, battery charge was 60% (yikes!)
- So, then I charged it again to 100%, let it sit overnight disconnected from car. Checked in the morning, battery charge was 80% (still a 20% loss).

So does this likely mean that my battery is simply no good, since it loses 20% of it's charge unconnected and 40% connected (meaning that perhaps the minimal load of the car's clock, etc. was causing big drainage)?

I still need to check the wires to the starter and the starter grounding, but what I've discovered so far SEEMS to point to a bad battery.

Any thoughts from the more experienced here?

What were the voltage readings?

In general it seems you have a weak battery and it is either dry inside or just worn out. Is it a sealed for life battery?

In any case the loss of 20% of the terminal voltage with no load just sitting is not a good sign. Did it see a very large temperature change from "charged" to "next morning" measurement?

A good shop will do the same test and also see how the battery responds to being loaded. Yours sounds like it will fail that test.

Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

There was not a large temp. change between the "charged" and "next morning" measurements (maybe 10-15F at most).

It is a "zero-maintenance" sealed-for-life battery.

The voltage reading when it was charged was 12.8-12.9. The voltage reading in the morning was 12.1.-12.3. When the car is running at idle the voltage reads 13.9-14 (indicating a working charging system).

Yes I think a load test is in order.

My 300CD will reliably start down to 15F without a block heater. I have (THANKFULLY) never tried to start her in colder weather as it just does not get that cold in Atlanta. Even at 15F it lights off quickly after 2 glow cycles (just to be safe.)

15F starts should be a breeze if you have:

- Good glow plugs
- Reasonably fresh battery
- Strong starter
- Regularly adjusted valves

I even run Rotella 15w40 dino oil, year round - never felt the need for thinner oil in the wintertime.

An ohmmeter does NOT always tell you the full story on your glow plugs. Every circuit in my glow system tested fine w/ my meter but I still had no glow plug light on the dash earlier this summer. Never did figure out which one was not working - I just replaced all five plugs as a preventative measure.

OK, so I tried something out, I don't know if it's a meaningless test or not though...

With the battery output reader hooked on, the output was 12.3V (battery was discharged to 55%)... then, I switched the car to the glow plug cycle and the output dropped to 6.8V... is it supposed to drop that low, or does that mean that I simply have a bad battery that has a "surface charge"?

OK, well I just purchased a new battery for the SD. I got it from Kragen for about 100 bucks. It's "Autolite" brand, has 1,000 CCA's, a 1-year free replacement warranty and an 84-month repair warranty.

Hopefully this helps.

I have never had any starting issues before in the 84 300D. Even below 20 F she cranked like a champ. I have recently (last 8 months) introduced B-20 biodiesel and have been running it consistently. I have changed the filters, replaced the battery, and had an oil change (Jiffy Lube diesel weight). However, recently on cold mornings (<40 F) she has been difficult to start and multiple glow cycles don't seem to help. When she finally has fired up, lots of grey smoke and rough idle. Yesterday morning she would not start at all, even after about 10 attempts. She turns over strong, but will not fire.

I suspect glow plug failure (I believe that they are prolly original and the car has 215K miles), so I will try replacement and report back.

__________________
I may sound like an idiot, but don't let that fool you...I'm not as smart as I seem.

'84 300DT Light Ivory 215K

Atlanta Metro, GA

thesst,

Did your new battery solve your problem? Seems like it should have taken care of the weak battery you identified. If the battery was more than three or four years old, then there probably is no other "lurking" issue that caused the battery to die prematurely.

InDiesel,

I am not presently using any BioDiesel mix, so I have no first hand experience to pass along. I am not sure but I thought others on this site had noted using much more than a 5% mix of BioDiesel with 95% dino Diesel can cause flow issues, and starting depends strongly on a good flow fuel through the nozzles of the injectors to atomize the injected volume. Globs of injected fuel are just not going to ignite, and neither will a drizzle. I thought you had to heat the fuel in cold weather to get it to behave, but I could be wrong. Which would mean heating the fuel lines between the injection pump and head so that volume, which is your starting volume, will work. I am pretty fuzzy on the details but at higher mixtures I thought you needed two tanks and you shut down on dino Diesel and started up on dino Diesel, just to avoid these kinds of issues. You may get by by adding a fuel conditioner to prevent gelling.

Nothing kills a starter or a battery like a Diesel that won't reliably start.

Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)