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View Full Version : Is idling for extended periods bad?


bigtexan99
10-11-2013, 11:25 PM
Can someone explain why idling the engine is so bad? I have a Powerstroke 7.3 and I let it idle all the time with no issues. That said, I'm considering buying a Sprinter, but one of the things I would want to do with it is to let it idle to power the AC.

Any tips on how to accomplish this would be appreciated.

I've searched a few threads here and the consensus seems to be that idling is bad.

lindenengineering
10-11-2013, 11:44 PM
In short yes!
Fifteen minutes of idle time is considered the maximimum.
Besides excessive idling is pollutive and is one of the reasons why big rigs have to APU's in some states like here in Colorado and of course dare I mention it? California:smilewink:. Idling only allowed for 5 minutes.
AND.
It wastes fuel going nowhere, reasons enough I suppose.

On a technical discussion it causes glazing of cylinder bores, washing of the cylinder liners/cylinder wall , and excessive carbon build up/carry over. Much of this is that the cylinders cool at idle reducing combustion efficiency and excess carbon residues end up in the oil.

So in short it should be avoided.
Dennis

NelsonSprinter
10-12-2013, 03:15 AM
It's not a powerstroke, it's a Mercedes that needs higher RPMs to keep it clean inside.
It can be done with a high idle setting if equipt with that option. Best is to use a generator to power an AC when not moving.

rhemsher
10-12-2013, 03:36 AM
How 'bout a brick [or stick] on the accelerator!!!! LOL! :smirk:

There have been times I have run down both of my coach batteries and need to get a charge in them in order to start the genset. I have "assisted" the RPM in order to get a quicker charge. Any idea what the "optimal" idle speed would be for an extended run? :idunno:

Aqua Puttana
10-12-2013, 03:57 AM
...Any idea what the "optimal" idle speed would be for an extended run? :idunno:
The newer models have adjustable high idle.

I recall 1500 rpm being mentioned as common for the fixed high idle T1N ambulances. High idle has all been discussed at length so a search from the blue bar above will get you more information and opinions if you're interested. vic

mean_in_green
10-12-2013, 05:24 AM
Mercedes-Benz call extended idling "extremely arduous operation" and require service intervals to be correspondingly reduced.

jmoller99
10-14-2013, 08:03 PM
It tends to clog up the EGR valve (many hundreds of $ to buy a replacement, however you can always try manually cleaning it). I clean my EGR every year, however the 2002/2003 has more EGR clogging issues than the 2004 thru 2006 T1Ns EGR valve.

Dingo
10-14-2013, 09:07 PM
YES .

Partially burnt exhaust gases are pulled into the inlet via the EGR valve & sticky oily rubbish builds up in manifold & on valves , coats your cat & if fitted the DPF with the same rubbish

The only real way to keep them clean is to NOT let the engine idle for any more than absolutely necessary , careful town driving fails to raise exhaust gas temp to a level that will make the DPF re-gen . Further due to low gas speeds , the soot builds up , clogging everything downstream of the engine ( turbo , pipes , filters , egr Etc.)

sooty crap build up can also hold EGR open leading to even more problems . So get it on a good run & wind it up & watch that soot fly

A diesel engine works far better when working under a load rather than simply running at elevated revs & no load , you stil do not raise the exhaust gas temp to a level that will clear soot & oily deposits .

An engine tramping up & down the highways is always cleaner than town engine due to higher temps , reduced moisture in crankcase

lindenengineering
10-15-2013, 03:20 AM
Dingo
In other words
Scouser expressions apply:-

Drive it like you stole it--and don't stop at red lights too long otherwise when they turn green someone will have stolen the wheels off your rig--- "whack"!
Dennis:laughing:

Dingo
10-15-2013, 07:58 AM
Very cruel Dennis :rolleyes:

Scousers have never given me any problems . Had far more events around Preston to be honest

But it is true , work the engine rather than pamper & it runs so much better & cleaner , i personally try to avoid the governors getting to join in the party as the engine begins to sound harsh .

Anyway , you are mocking my liverpudlian neighbours ..... what about the gangs in your replacement 'hoods ????? Are they any nicer ?

:thumbup:
I am smiling as i type mate

Tarleton !!!! do you have extra fingers ?

unik
10-15-2013, 10:36 AM
I do (did) Idling as many as I needed. Specialy in a summer time to run AC for my sleep inside. I live in Florida where summer is hot.
My Sprinters ODO 65,000 no problems with engine. Made in April 2006y. Owned from May2006y.

lindenengineering
10-15-2013, 02:37 PM
Very cruel Dennis :rolleyes:

Scousers have never given me any problems . Had far more events around Preston to be honest

But it is true , work the engine rather than pamper & it runs so much better & cleaner , i personally try to avoid the governors getting to join in the party as the engine begins to sound harsh .

Anyway , you are mocking my liverpudlian neighbours ..... what about the gangs in your replacement 'hoods ????? Are they any nicer ?

:thumbup:
I am smiling as i type mate

Tarleton !!!! do you have extra fingers ?

Dingo
Well totally off topic and adding some mirth
Where I live now in Colorado (Denver suburb) is much like Tarleton really "nothing ever really happens"!:laughing:
'cept perhaps hard up Landrover owners hoping I can pull a rabbit out of the hat!:hmmm:

Here's what I mean!
I used to show this series to my kids when they were small so that they would keep some of their English accent (fat chance) But no scoucer lilt mind yah!

http://www.youtube.com/watch?v=u_dEv5Uv7EI

Guys here's something to think about--alright tigah!:laughing:
Enjoy
Dennis

Boater
10-15-2013, 03:45 PM
Never had any problems driving through the middle of Liverpool, or on the Wirral, but up Ainsdale/Southport way I generally see some sights and always wonder when my luck is going to run out!
Being on the beach after dark is bad - the kids are not just driving it 'like' they stole it.....:eek:

Anyway, best not to annoy scousers, they will take offence - gate posts and all!
(the old jokes are still bad!) :bounce:

Got some good friends who are scousers, always have a good time down there! :cheers:

The only idling going on here is us now boys!

SullyVan
01-12-2014, 03:52 PM
My gasoline generator isn't getting a spark, my batteries are down from a week of the Sprinter left unattended and I have another week to leave it unattended while I work starting tomorrow.

Very busy. Not enough time to work on stuff.

Getting 35 amps @13.6 vdc @ 1300 rpms out of the alternator on "sick holding the pedal" high idle.

That's about a half a kW hour load on the engine, plus pumps for fluid, all running lights on, etc....

Is this ok for 4 or 5 hours at a time, done twice over the next couple weeks while i figure out what to do with my generator?

Sure wish I had solar about now!!!!

SullyVan
01-12-2014, 04:28 PM
And this is odd.

Idling at 1200-1300 or so, making power, using a stick on the pedal is working, but....!!!!

Every half hour or so, the engine starts to run away! What's that all about? It just jumps to 2400 RPM, staying there. Then i remove the stick from the pedal and put it back in place.... 1200-1300 RPM for another half hour.

More wonderful Mercedes electronics issues?