Idling is bad mmkay

[asleepz]

I'm just going to leave these here and see where it goes.

For the record the engines (Cat 3508B) had a top end overhaul around 35,000 hours, no failures, and oil/filter changes roughly every 2000-3000 hours. Almost 80 gallon sump. Mobil 410NC SAE 40. Baldwin filters.

Disregard the diagnostic on one. Due to a fuel pressure sensor on the fritz.

For the record, do I want to idle these engines like this? No... But due to a marine environment it's part of the gig.

 

[Tegger]

Idling is bad 'cause it's bad...

 

[CourierDriver]

The word bad conjures up different definitions in people's mind...diesel are made tough and idling is not a big deal..big rigs do it all the time and its a part of their environment. I was a part of that environment for awhile, never thought a thing about it.

 

[The motor guy]

What's this on a tug boat? I guess the question would be is 35,000hrs a reasonable amount of life for that engine?

 

[The motor guy]

It's got like 70 percent idle time.

 

[The motor guy]

I believe in the marine industry they actually rate engine lifespan by gallons of fuel burned, not hours.

 

[asleepz]

Originally Posted By: motor_oil_madman
I believe in the marine industry they actually rate engine lifespan by gallons of fuel burned, not hours.


You would be correct. This tug stays and works a fleeting location so it doesn't go far and isn't under high stress 24/7 like line haul divisions.

Hard life though, lots of standby idle then direct to full load. 1300rpm limit typical RPM at full load around 1200-1250.

As far as actual life goes, not sure. As long as the block doesn't have a hole in it the size of a school bus everything else is serviceable.

 

[SeaJay]

Less than 7 gallons burned per hour suggests quite a bit of idling. It of course varies on the config of the particular engine (as various versions were rated at different HP) but those engines do burn quite a bit more fuel than that while at full cruising speed.

 

[Astro14]

Originally Posted By: Tegger
Idling is bad 'cause it's bad...


Idling a diesel isn't bad.

Idling a carbureted gasoline engine can lead to fuel dilution, washdown of cylinder walls, carbon fouling, and excess wear.

Depends on which kind of engine you're idling...

 

[ragtoplvr]

Cold starting a diesel and letting it idle until warm is bad for the diesel. Best would be to run at moderate load and RPM until warm. For a marine diesel , some can be started and go to load right away, some can not. For example backup genets are started, go right to 1200 RPM or 1800 RPM and rated load in a few seconds. There are some engine design parameters that need addressed for this to work.

A semi my neighbor had would build up unburned fuel in the exhaust when idle in winter. Would belch flame when he pulled out on the road. Kind of impressive. Had to be horrible pollution because if the wind was wrong it stunk outside my house. Some can wash lube off cylinders, most don’t. Called cold stacking.

A already warm diesel to idle between uses in not nearly as bad. In northern winters they can lose their heat see cold stacking above.

Idle is bad for the air though. More particulates, more unburned fuel. There is a lot of fuel wasted.

The modern way is an aux power unit with a 2cy motor that keeps the main engine warm, provides stationary power and when the main is started the oil and water is warm, so can load it in a few seconds after start.

Rod

 

[asleepz]

These engines don't load up terribly. Maybe after sitting for 6-8 hours they smoke heavier for 1-2 minutes.

38-42 gal per hour full tilt, 3.5gph warm idle.

If I do get the chance to shut down the engine rarely does it sit long enough for oil temps to dip below 100F, so she may get 3-4 minutes of light load, then lay the hammer down.

Our 3508Bs are rated at 775hp

 

[The motor guy]

Originally Posted By: ragtoplvr
Cold starting a diesel and letting it idle until warm is bad for the diesel. Best would be to run at moderate load and RPM until warm. For a marine diesel , some can be started and go to load right away, some can not. For example backup genets are started, go right to 1200 RPM or 1800 RPM and rated load in a few seconds. There are some engine design parameters that need addressed for this to work.

A semi my neighbor had would build up unburned fuel in the exhaust when idle in winter. Would belch flame when he pulled out on the road. Kind of impressive. Had to be horrible pollution because if the wind was wrong it stunk outside my house. Some can wash lube off cylinders, most don’t. Called cold stacking.

A already warm diesel to idle between uses in not nearly as bad. In northern winters they can lose their heat see cold stacking above.

Idle is bad for the air though. More particulates, more unburned fuel. There is a lot of fuel wasted.

The modern way is an aux power unit with a 2cy motor that keeps the main engine warm, provides stationary power and when the main is started the oil and water is warm, so can load it in a few seconds after start.

Rod


Gensets such as ones used for hospitals have a block heater connected at all times usually.

 

[Shannow]

Couple of data points...

My Colorado was a demo model, had 4,600km on it when I picked it up...even though the OCIs are 15,000km, at 4,600km, the oil life monitor was down to 38% remaining...had 130 hours on the engine, 31 idling. Now at 8,000km, it's down to 24%...only 32 hours idling, so the GM oil life calibration is hit pretty hard by idling (900km round trip, the OLM didn't change).

Wifes new (to us diesel Captiva spend 6 months in a car yard, being driven from the front gat to the back yard ever morning and back every night. Smoked like a 15 year old when I test drove it but cleared after 20km...oil level is WAY over the full mark, but I fix that this weekend...that operation is an aberation, but my wife in her former job drove a half mile to work, so not REALLY not real world.

 

[CourierDriver]

Time to close the water cooler gang...................

 

[The motor guy]

So are you getting the same engine life as other boats with those engines?

 

[The motor guy]

What happened that caused one engine to have more hours than the other?