Idling

[Mr. B]

I've heard from some Sprinter owners that prolong idling is bad for the diesel.

If anyone have a technical experience - is it okay to idle for two-three hours?

Thank you!

[xrvr]

There used to be a high idle option for the earlier sprinters, don't know if the newer ones have that. Extended idling is generally bad for the newer diesels.

[Mr. B]

Can you briefly explain why?

[xrvr]

Go to the sprinter forums and use the search function.

[Mcrid]

The owners manual says it can harm the emissions system. I've also read,but find hard to understand, that it can result in insufficient lubrication for the top side

[overlander63]

Originally Posted by Mcrider

The owners manual says it can harm the emissions system. I've also read,but find hard to understand, that it can result in insufficient lubrication for the top side

Several things in play there. First, after lengthy idle time, the lube oil can thin to the point it no longer be pushed through the system in sufficient pressure to get to everything at the furthest point from the pump. Also, some things are "splash lubed", and may not get sufficient coverage at low speed. "splash lube" parts would be valves that only get the oil that flows across the valve train, and onto the top of the valves, to run down them and lube the stems.

[Mr. B]

Avionstrem, go there yourself.

Overlander, thank you for the detailed explanation!
I've also heard the Particulate Filter may clog once at prolong idling?

[Protagonist]

The reason why the emissions system can be damaged is a phenomenon known as "wet-stacking." You don't see it much on vehicular diesels, except semis that idle overnight while the driver sleeps. Normally you see it on diesel generators that are under-loaded. You get incomplete combustion— and lower exhaust temperatures— leading to a buildup of carbon compounds in the exhaust system, including on the exhaust side of the turbocharger as well as in the exhaust treatment system.

It's called wet-stacking because semis and many generators have a vertical exhaust stack.

[xrvr]

Originally Posted by Protagonist

The reason why the emissions system can be damaged is a phenomenon known as "wet-stacking." You don't see it much on vehicular diesels, except semis that idle overnight while the driver sleeps. Normally you see it on diesel generators that are under-loaded. You get incomplete combustion— and lower exhaust temperatures— leading to a buildup of carbon compounds in the exhaushut system, including on the exhaust side of the turbocharger as well as in the exhaust treatment system.

It's called wet-stacking because semis and many generators have a vertical exhaust stack.

I don't have to go there because I've already read it. You need to do some of your own research, you'll find it illuminating.referring to post 7

[Protagonist]

Originally Posted by avionstream

I don't have to go there because I've already read it. You need to do some of your own research, you'll find it illuminating.referring to post 7

Did you mean to quote me in that reply?

[J. Morgan]

The reason they used to say prolonged idling was bad is because when combustion temperatures drop in prolonged idling, the fuel does not burn completely and it washes the oil off of the cylinder walls causing rapid piston, ring, and cylinder wall wear, and even scuffing in extreme cases.

Additionally, common sense says Incomplete combustion is going to cause issues with particulate filters etc.

That said, back in the day when I spent a lot of time in trucks, I idled them overnight anyway, but I would bring the engine up to about 1,000 rpm.


Superat stultitia.

[toskeysam]

Lower exhaust temperatures associated with idling have more particulate in the gas stream due to incomplete combustion. Over time that causes problems for the emissions controls items. The "high idle" generated higher temperatures to burn this off, just like normal driving.


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[toskeysam]

Sorry for redundant answer.....my screen did not show all of the responses given.


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[Protagonist]

Originally Posted by toskeysam

Sorry for redundant answer.....my screen did not show all of the responses given.

Don't apologize. Multiple people independently providing the same answer just means the answer is more likely to be correct.

[lewster]

I think that you can still order the high idle function on a new Sprinter, but they are not standard equipment. I just had my 2011 Sprinter 2500 serviced prior to my departure Sunday for Oregon, and had a long conversation with the Mercedes Sprinter specialist about several issues.

Primary in this discussion was idling. Along with what has been stated above (most of which applies to Sprinter diesel engines) the biggest problem is excessive sooting of the EGR (exhaust gas recirculating) valve. This part has a wide and varied effect on the performance of both the engine and transmission and excessive idling WILL plus it with exhaust soot.

Even though I don't idle mine much, I replaced the EGR at 100,000 miles as a precaution. There are several Utube videos about how to clean one, which I have done to my original EGR and will probably have it re-installed at 200K, or whenever I notice issues with decreased fuel mileage or shifting anomalies, both of which are signs of a clogging EGR.

[xrvr]

Originally Posted by Protagonist

Did you mean to quote me in that reply?

No referring to post 7 I think. Sorry!

[DKB_SATX]

<* Putting on mod hat *>

Please take to heart the Community Rules which lead with "Be Courteous."

[Mr. B]

Actually as per some information, the filter can be cleaned by burning the particles on a highway high speed:

https://m.youtube.com/watch?v=WUOhqqyu3RY

[lewster]

Originally Posted by Mr. B

Actually as per some information, the filter can be cleaned by burning the particles on a highway high speed:

According to me Mercedes tech, that doesn't necessarily work. The fix was to manually clean the EGR with a vibrating tooth brush and carb cleaner.


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[Mr. B]

Do you think this filter is the biggest subject of a negative effect caused by prolong idling?