Thinking my 240D might be on it's last legs. Over the last month or so its become increasingly difficult to start it in the morning. Though once I get it going its fine for the rest of the day. This morning It took almost five minutes of cranking before it fired up, with a large cloud of greyish blue smoke. Just wondering if the symptom indicates a worn out motor?

I mean it's ok when warmed up. My job requires me to drive around a lot during the day so once it's warm I have no issues but that first cold start is becoming almost impossible.

- Peter.

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2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S

Time to check glow plugs and adjust the valves.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Are you losing oil? Holding oil pressure ?

Could also be air in the fuel system, all the cranking primes it, but in doing so it also pushes some oil past the rings?

sounds reasonable to me. if it were my car, I'd start with glow plugs like diseasel300 said, then if glow plugs are all functional, pump the hand plunger primer pump until you hear the overflow valve release to see if its losing prime

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1982 300D (w123, "Grey Car")
1982 300D (w123, "Blue Car")
2001 Ford F150 "Clifford" (The Big Red Truck)
1997 Dodge Ram 2500 12V Cummins
1996 Dodge Ram 2500 12V Cummins
Previous Vehicles:
1995 E300D, 1980 300SD, 1992 Buick Century, 2005 Saturn Ion

glow plugs....classic symptoms.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

If you pull the glow plugs, do a compression test. 330K on a OM616 is starting to get close to expected life time.

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“Whatever story you're telling, it will be more interesting if, at the end you add, "and then everything burst into flames.”
― Brian P. Cleary, You Oughta Know By Now

I know it's long overdue for a valve adjustment. I plan to do one this weekend. I also have a GP issue. I replaced the plugs about two years ago with Monarks, but subsequently when troubleshooting my antenna I messed something up with continual cycles of the ignition system and my GP light now doesn't work. Though I can hear the relay clicking off after 26 seconds when I'm trying to start it. So don't know what's going on there. I'll probably troubleshoot the GP's as well while I'm "in there" with the valve adjustment. Don't have a compression tester so that will likely be beyond my ability for now. Air in the fuel system is something I'd not considered. Might be an idea to change the fuel filters as well but there's only so much wrenching I can tackle in a weekend.

- Peter.

__________________
2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S

As long as you're at it you might as well check your battery voltage. It should produce about 12.6V, but may start down to 12.4V or so depending on weather. If your battery is nominally holding a charge, you could have similar symptoms.

Dkr.

I sure wouldn't jump to a conclusion of "worn-out engine". A better test for that is to judge blow-by coming out the oil filler hole when idling (see youtube). In my 5 cyl, a designed-in indication of "failed glow plugs" is that the glow-plug lamp doesn't light when a certain number (2?) have burned out. I imagine your 4 cyl has similar, so that lamp is telling you something. Don't dally, it takes me 1 min to check all glow plugs. I pull the plug in the engine bay and measure ohms from each of the 5 pins to gnd w/ my free HF multimeter. If bad, they measure infinity, good <5 ohm.

I just found a bad one in my 1984 yesterday and replaced it. The old one had an "M" symbol, which could mean Monarch, and I probably installed it ~20K miles ago. Previously, I recall most/all failed ones were Bosch, but maybe just what the PO's used. I installed a cheap VSP one (ebay) and have used for ~3 yrs and don't recall removing any failed VSP's yet. The engine started faster and idled smoother cold with all 5 glow plugs working.

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

I shall be checking battery voltage and glowplugs this weekend amongst the other stuff.

Sure do hope it's not terminal as I've just fixed a bad power steering fluid mess from the failing PS pump front seal last weekend by replacing it with one from a junkyard 300D with 100K less miles on it than mine so I was feeling pretty good about it.

- Peter.

__________________
2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S

+1 on the glow plug light being a indicator. sometimes mine doesn't light if there is 1 plug out. but seems more likely when more plugs are bad.

I'd highly doubt its "worn out", especially with it being a little cooler recently, this is the time of year all the starting problems tend to show up for me as well.

I did the resistor mod to show when the plugs are actually active by GP light at half brightness, I love that setup, because if the light doesn't come on at all, a fuse is blown or something is awry, but if it comes on half bright, then I know I've got plugs out.

I've had a bad rash of bad diesel recently, took out my grey car and blue car, clogged primary filters multiple times, and then when I finally got the primary to stay clean and the car still ran like junk I discovered the tank strainer clogged solid.

My dodge survived (to my belief anyway) thanks to a giant goldenrod mesh strainer I put inline with the fuel. it has captured nearly a cup of watery slime during this diesel debacle around me.

I'm slightly curious if tanks got contaminated with water during the hurricanes and such and all that fuel got shipped to East TN. or if the tanks here took on water with all the rain and aftermath we caught.

I've since purchased more giant goldenrod filters and will be locating a spot on both of my cars to place them.

__________________
1982 300D (w123, "Grey Car")
1982 300D (w123, "Blue Car")
2001 Ford F150 "Clifford" (The Big Red Truck)
1997 Dodge Ram 2500 12V Cummins
1996 Dodge Ram 2500 12V Cummins
Previous Vehicles:
1995 E300D, 1980 300SD, 1992 Buick Century, 2005 Saturn Ion

Interesting, I'd not heard of that before. That sounds like an excellent idea. I doubt' we have a bad diesel situation here as the problem occurs exclusively at cold start in the morning. No issues for the rest of the day.

- Peter.

__________________
2021 Chevrolet Spark
Formerly...
2000 GMC Sonoma
1981 240D 4spd stick. 347000 miles. Deceased Feb 14 2021
2002 Kia Rio. Worst crap on four wheels
1981 240D 4spd stick. 389000 miles.
1984 123 200
1979 116 280S
1972 Cadillac Sedan DeVille
1971 108 280S

There are only two brands of glow plugs that on average offer decent lifespans. Monarchs are not one of them to my knowledge.

You should address this as soon as possible as the starter and battery are not appreciative of the start cycle currently being used. Bosh glow plugs are about the only good ones easily obtainable for these cars.

Periodic valve clearance checks and adjusted if needed are also pretty high on the list going into colder weather. If not done almost forever best to do it several times in short order.

Personally I also believe the fuel system should also be examined. There are components that weaken or become problematic with age in many cases hiding there. Although in your case the probable major issue is the monarch brand glow plugs. Just checking the resistance of each one should locate any open ones. If you locate any open ones replace them all with bosh.

As for a worn out engine. Usually I base this on base oil consumption with these engines. Never a certainty but if you are going through excessive oil consumption with no leaks things are not great.

I personally like to see better than 1000 miles a quart or less usage on the 616 engines. They burn more Base oil on the highway because the piston speed is much higher than the five and six cylinder diesels. I always assumed their oil control rings where not the best.

I do not know if the glow plug relay on the 616 has any feature that indicates issues. Since I have never lost a glow plug on a 616. Also people assume all kinds of things. Any milage indicated by the odometers on these cars is suspect. Unless there is some reasonable proof it is accurate. Your engine could as easily be a replacement with another than as not. We get these cars usually with few to no service records and past history. Good used lower milage engines where a dime a dozen not that many years back for these cars.

Never buy glow plug brands other than Bosch or Beru, which may in time end up with a swollen tip that eventually may fall off. In an engine such as your's, a broken off tip will just wreck the pre-chamber, in engines w/o pre-chamber, it will wreck the piston, valves, head, block.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Glow plug(s)...your frequent starts during the day cut the "calendar days" kind of longevity measurement.


Over the years with daily multiple starts (4 +) & on two - three year intervals, one or two plugs within a replacement set (bosch & beru) go out, making for hard morning starts. The car never sees <40* F, Even at 50* a single bad plugs makes for an old jalopy like start.

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1986 300SDL 440,xxx