What is your Diesel engine cranking speed? - Page 2 - PeachParts Mercedes-Benz Forum

Cervan · #16 07-20-2008, 12:00 AM

Quote:

Originally Posted by pawoSD

The tach is too slow to measure that, the engine starts so quickly that all that tach does is sort of bounce up to 800rpm....it does for me anyways. Mine starts in about 1.5-2 seconds with a 5 second glow (just till the light goes out) at temps above 35 degrees.

If I roll down the hill from my apartment and put it in L while rolling in neutral around 18mph it starts in about 2-3 seconds and revs up to about 1500rpm right away. Does that count?

It will do it with no glowing too.

takes about 15 seconds for me to start mine without glowing (just cranking it) ill have to try to roll start it without glowing...

pawoSD · #17 07-20-2008, 12:04 AM

If I try to start it cold with no glowing using the starter it takes mine about 8-10 seconds at temps above 50F.......our 300D can do it in 5 or less....that engine is in amazing shape.....but it also has a 6 month old starter.

Cervan · #18 07-20-2008, 01:18 AM

Quote:

Originally Posted by pawoSD

If I try to start it cold with no glowing using the starter it takes mine about 8-10 seconds at temps above 50F.......our 300D can do it in 5 or less....that engine is in amazing shape.....but it also has a 6 month old starter.

I just did it, it took about half a second when i was going down the hill cold. so i guess my engines in good shape lol.

whunter · #19 07-21-2008, 01:22 PM

Quote:

Originally Posted by ForcedInduction

Around 200-300rpm depending on the outside temperature.

This is what I am looking for.

pawoSD · #20 07-21-2008, 01:35 PM

Imagine how easy they'd be to start if they had twin batteries and a 2.5kw 500rpm starter, instead of what is on there. (1.2kw)

We'd never see a "Trouble starting in the cold" thread ever again!

argus445 · #21 07-21-2008, 05:49 PM

mine reads between 300-500 cranking this is with fuel on as normally u would be. new starter + battery in 95 degrees @ roughly 12v since glow plugs still engage for 15 sec or so..

bustedbenz · #22 07-21-2008, 07:06 PM

My tach seems to have no power to move while the key is in the starting position. It stays at zero until I release the key back to "run", at which time it hops straight to whatever RPM the engine is idling at. Useless while cranking from the ignition switch. I'd have to jump the starter under the hood.

pawoSD · #23 07-21-2008, 08:26 PM

Quote:

Originally Posted by bustedbenz

My tach seems to have no power to move while the key is in the starting position. It stays at zero until I release the key back to "run", at which time it hops straight to whatever RPM the engine is idling at. Useless while cranking from the ignition switch. I'd have to jump the starter under the hood.

Same here, my tach stays around 0 then comes up when it starts....

Skippy · #24 07-21-2008, 08:43 PM

I don't know what speed my engine cranks over at. I'll watch the tach next time I start the 300, but the tach only works when it wants to.

In mechanic school, I was told that diesel engines in general need about 150 rpm to start. However, from experience I've seen N-series Cummins with starters that barely kicked them over that still started easily. The slow cranking might have been from the fact that the starter in an N-series seems to be about the same size as the one in my 240D.