I started all three of my diesels this morning around 5am at 17 or so degrees.. Both my 99 E300 and 92 300D have had issues with coughing and misfire at cold start and some grey smoke. The 92 300D had always done that, I thought it was just wearing rings and the black car hadn't had issues with smoking at all until two weeks ago. Well, followed the dieselgiant steps and found out I had 4/5 dead glow plugs on my 92 300D and 3/6 on my 99 E300. Both started without issue, a little extra crank time but didn't stall out once. I would like to think the white car has great compression for its mileage at that point.

Looks like I'm doing the om606 glow plug nightmare, and om602 shouldn't be half as bad. I think if I run the 99 nice and hot on the highway and plug it in and keep the motor warm and use air tools, it should get those glow plugs out no issue.

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Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

Recalls when I helped start a fellow Boy Scout dad's diesel (Ford Bronco or such, forgot) at Lake Tahoe after a ~0F night. Even though in a garage, we had to run a blow dryer down the intake for 30 min to get it started. He later found it was just bad glow plugs. Winter in the Sierras can be a wake-up. Good luck. I read that changing glow-plugs in newer engines is much harder than my 80's OM617 engines.

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

OM606 is easy. Remove the intake manifold, run the engine at idle until it reaches operating temperature, turn it off, hit the plugs with the impact gun, done. Use the natural expansion/contraction of the aluminum head to your advantage rather than working against it.

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CENSORED due to not family friendly words

Interesting story, Bill. It doesn't seem too bad on these cars. It requires intake manifold removal, other than that, cake. I've never done them on an om617.

Tits, any idea how bad it should be on the OM602? Thanks for the advice. I've read so many horror stories. I think it can't be that bad, it has to be the mechanic who's doing it to cause the issues that I've read.

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Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

617s light fast when glow system is working and engine running well. 00 Dodge Cummins kicks faster but that is because of more modern electronics. Both are beautiful engines. Dodge falls apart around the engine and takes work to bring back. MBZ should never be let go but they have been and need work also.

Edit: Synthetic oil makes the difference in cranking speed on the 617.

I sent a Cummmins oil sample to Blackstone at 12,0000 mi. They said to run up to 15,000 and check again. Running full synthetic of course. Nice to change oil once/year.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

The 60x series engines seem to be pretty tolerant of starting, even with major problems. I'm pretty sure if you kicked the wheel hub hard enough, they'd start...

My poor SDL has an average of 350PSI compression and it fired up when the IP was 360˚ out of time, on 10 year old diesel, 2 injectors seized shut, injection pump with ruined bearings, and glow plug relay that thought 1 second of glow time was adequate. Still started on the 4th or 5th compression hit...

Now with new DV seals, balanced injectors, and a glow plug relay that works properly, I let it glow for ~10 secs in the morning and simply blip the key and we're off to the races. That car is less cold-natured than my Honda and 25 years older...

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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!)

I would do some reading here before hitting the glow plugs on an OM606 with an impact wrench. Most I have learned is use a torque wrench that lets you set the specification in the CCW direction also. I forgot at what amount of torque they snap (major problem) but there are plenty of threads on it here. I plan on pulling mine mid summer if they need it or not, and not looking forward to it.
P.S. a 13 degree F start on first compression stroke around an hour ago.

My early '02 Dodge starts in cold weather even when I forget to glow it though it runs better if I do. And I've had little trouble with mine "falling apart around the engine" though I do maintain the truck. At 235K miles I have zero complaints - I LOVE that truck!

On the other hand, I have to glow Mutt's 617 every time I start it, even when warm. It runs fine and obviously makes great power but it DOES want some heat to fire up. The compression, while a bit low, is pretty normal given the miles on the engine, the IP is in tip-top shape (it did this with the stock pump and with the SuperPump), the timing is spot-on, and I don't know what else to check. Evidently this is just a quirk of my engine.

Dan

I've discovered the glow cycle time is a tad short in my 603. I think I have an issue with the relay because it doesn't glow very long in cold weather or ever. I think the maximum time is like 30-45 secs but my light will actually go out after around 15 secs maximum.

So basically if my relay is working correctly on the coldest days you get a full 30-45 sec glow which is great and heats the plugs fine, but then power is cut to the plugs as soon as the starter is engaged. So the plugs immediately begin to cool while you are cranking and moving cold air into the cylinder. This is rare design flaw IMO.

This was an issue with me because the car would start with the short glow and no afterglow but would run rough at first. Kind of embarrassing in some situations and probably not great for the engine.

I've found a nice long glow is usually beneficial if it gets below say 20 °F. Then I prefer at least 30 secs of glow time and a few seconds of afterglow on a cold engine. A shorter time will start the car but why stress the engine if you don't have to?

So in comes Jeremy's purple wire mod which is great for improving cold starts, the afterglow helps a lot to get the engine running smoother quickly. Sometimes on very cold days I'm not sure I could start my car without afterglow.

When it's really cold below 10F or so I always glow for a good 45sec-1.5min and use the purple wire mod to ensure I get afterglow. To do this I end up cycling the ignition at least twice each time I start the car. Once first for 20-30 seconds to heat the plugs, then I quickly cycle the key to start a new glow cycle, then when I think I'm about halfway through the second cycle I hit the starter, thereby ensuring I get a good 15 seconds of afterglow and the plugs are hot from the first cycle and first half of the second cycle. This has resulted in the smoothest cold starts for me, although it can stress the battery, if it is small or old.

FWIW I've been using Auto lite plugs for 4 years now and during that time I've also been using Jeremy's afterglow mod so each time I cycle the plugs I get a full glow no matter ambient temperatures. That's a lot of glowing, and so far I have no complaints on Auto lite plugs. If they can start my car at -12 °F that's good enough for me. Much colder than that and I'm going back inside for tea!

Cheers gents

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"Sometimes I sits and thinks and sometimes I just sits..."

The light goes out after 10-15 secs by design. The relay will continue to run the glow plugs until it times out if the key isn't turned, so you'll get the full 30ish secs of glow, even after the light goes out.

The coldest I've run my car has been in the mid 20s so far (it hasn't gotten colder than that here yet), and even at that my car started on the first attempt obeying the WTS light. I just wanted to see if it would work properly, and it does! In colder weather, I do let it glow a little past the light going out, and if it was sub-20˚, I'd probably glow it twice.

__________________
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!)