Is it necessary to run engine for 10-minutes when cold starting?

[KiwiKampers]

I ask this question because on several occasions I have been parked next to a motorhome in which the driver insists on starting the engine and leaving it running for ten to fifteen minutes before he drives off. I remember this was a habit people had about twenty years ago, but with modern Diesel engines is it really necessary? It’s very annoying when they start up at 06.30am.

 

[Jamesh]

It seems to me that many of the above folks don't drive vehicles with Euro 6 engines vehicles equipped with 'Stop-Start' or they would realise that this is not necessarily the case as such engines will stop instantly when the vehicle comes to a halt.

Still not best practice car company is only concerned about the reliability during warranty period rather than long term effects...?

 

[Bobbydaisy]

Leaving it running for long periods at idle will potentially create DPF clogging up if it’s not given a good run to bring it up to temp to burn off the build up thereafter . Been there with my last van , £1200 later realised my mistake …..

 

[rod_vw]

Still not best practice car company is only concerned about the reliability during warranty period rather than long term effects...?

Well to add to me comments above I do notice that the Stop - Start doesn't always do what you would expect so perhaps the algorithm and sensors ensure that a very hot engine does not stop. Obviously it doesn't work at times of a cold engine, need for maximum battery charging, aircon working hard etc.,

 

[airwave]

I ask this question because on several occasions I have been parked next to a motorhome in which the driver insists on starting the engine and leaving it running for ten to fifteen minutes before he drives off. I remember this was a habit people had about twenty years ago, but with modern Diesel engines is it really necessary? It’s very annoying when they start up at 06.30am.

Rather interesting question , and some of the answers are equally interesting .

Actually it's totally the opposite , yes it is necessary , even more so with modern diesels and their smaller bore oil galleries . Oil is thicker when cold meaning it won't flow anywhere near the same as when it's warm , and don't forget your already using a lower viscosity to transverse those passages now . The practice is to allow oil in sufficient quantity to reach critical areas for engine survival , including the turbine , commonly called oil pressure . The same goes for stopping where the engine requires time to stabilize oil pressure before shutting down , also allowing the turbine to spool down to acceptable limits , at the same time . My mothers Mini requires around 5 minutes to stabilize oil pressure , often rocketing to an unstable 80 psi on start , before settling back to 30 psi , and that's a 1.3 . Now it could be argued , that you've got 80 psi here . Well no , it's a false reading , the actual reason is the oil is restricted due to viscosity , and pooling around the sensor position . It actually has no pressure , and imagine your turbine is furthest from the flow , running without oil on start . Even worst , running after its oil supply is shut off , still rotating at 30-40,000 rpm , at maximum temperature . Turbine temperature climbs rapidly , but it's even faster with lack of oil . It's a pretty good path to excessive wear on the main bearings , and knackered turbo's . Many high performance turbo's use ceramic bearings , but even here they are still bathed in oil .
Question , have you never not wondered why air ambulance helicopters never shut down immediately after landing ? . It's the same thing , and those bearing are ceramic . I would question 15 minutes , but yes idle for a short period .
Now while on the subject , aircon is also misused in exactly the same way . Many people are under the impression , it's perfectly fine to just shut the engine down with the aircon running full chat . Well no , the correct procedure it to switch the system off two minutes before the engine , though this can and should be done while still driving . That's why a pool of water will always appears under the parked car . Aircon is a breeding ground for all kinds of nasties , and is very rarely treated properly , and worse even rarer , serviced . This is the prime reason i would never buy a second hand motor with aircon ! .

Good luck , with giving someone a mouth full , your more likely to get a mouth full in today's world ! .

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[Lenny HB]

I wonder how the engines in ice cream vans cope, some of them, especially if at a show or festival, sit on tick over all day ?

My motorhome is 27 years old - I’ve always warmed the engine before moving off - the engine has now done 300,000 and has only ever had/needed cam belt and consumables changed. When put on a rolling road a couple of years ago it still returned better performance and uses less oil than stated in the handbook!

Old diesels not so much of a problem no CAT, no DPF. not common rail.
Modern one leave them ticking over for ½ hour and they have still not got up to operating temperature.

 

[IanBt]

Thank you all for your comments. Next time it happens I’ll blast him with The Tremeloes at Volume 11.

I thought it was only ‘Spinal Tap’ that went up to ‘11’

 

[EuroTrotters]

One of my cars states in the hand book "For cold starting in Winter, allow the engine to run for a few minutes before setting off (NOT FOR GERMANY)"

 

[kevenh]

Do we need a bit less pseudo science and read our vehicles owner’s manuals?

Other than in winter when having the engine running and helping you de-ice/demist windows, start the engine, check for warning lights,going out, and then drive off.
Moving warms the engine up quicker than sat idling wasting time & energy

 

[EuroTrotters]

Do we need a bit less pseudo science and read our vehicles owner’s manuals?

Other than in winter when having the engine running and helping you de-ice/demist windows, start the engine, check for warning lights,going out, and then drive off.
Moving warms the engine up quicker than sat idling wasting time & energy

Yes, I miss my diesel pre-heater on my Van. But have one on may Car

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[kevenh]

Yes, I miss my diesel pre-heater on my Van. But have one on may Car

I’ve seen motorists with fires under their engines - if they aren’t running. But that was Astana, Kazakhstan mid winter,

 

[Silver-Fox]

Do we need a bit less pseudo science and read our vehicles owner’s manuals?

Possibly not, our Audi A3 manual says 100k for cambelt but main dealer said 50k or 5 years

 

[Silver-Fox]

Yes, I miss my diesel pre-heater on my Van. But have one on may Car

Van was a Sprinter?

 

[kevenh]

Possibly not, our Audi A3 manual says 100k for cambelt but main dealer said 50k or 5 years

Cam belt service intervals?
The OP is asking about starting an engine and idling for 10min.
The Audi A3 owners manual says do not sit idling to warm up the engine. But do “avoid high engine speed, full throttle, and heavy engine load as long as the engine has not reached operating temperature yet . You could damage the engine.”

 

[Spriddler]

I think that if we carry on doing what we've always been doing without any issues we'll be fine.

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[Silver-Fox]

Cam belt service intervals?
The OP is asking about starting an engine and idling for 10min.
The Audi A3 owners manual says do not sit idling to warm up the engine. But do “avoid high engine speed, full throttle, and heavy engine load as long as the engine has not reached operating temperature yet . You could damage the engine.”

It was mentioned in a post about reading the manual and going by that.

Possibly not the case with cam belts though.
Hence why I posted.

All needs to be read in context

 

[EuroTrotters]

Van was a Sprinter?

Van was a Sprinter?

My last Sprinter Van (not motorhome) had PTC heater and Diesel heater.

My current 2014 Sprinter does not. I have to block the radiator off in Winter

We had a frankia with Alde on a Mercedes’ Chassis with the factory fit diesel boost heater

The diesel heater fitted by Mercedes’ was only programmed to work with the engine running.

So I replaced the single heat switch with the Mercedes double heat switch and fed a single additional wire through to the dosel heater in the loom.

Next step. I took the van to euro commercials in Bridgend wales. They connected my wiring from the new Mercedes’ switch into the heater. Then went online to Mercedes and programmed the ECU. This meant I could now use the chassis fit heater without the engine e running.

This was then stored into Mercedes’ database. So, if it went into Mercedes’ for service or recalls, the program would not be wiped.

I could now use the manual Mercedes’ heater switch. Or program a time into the vehicles information display on the dash using the steering wheel controls (can also be done with dash buttons if you do not have the steering wheel buttons).

Then, I installed an Alde heat exchanger between the engine / diesel heater and the Alde boiler.

This meant, I could switch on the pump on the Alde. Using the waste heat from the engine, we could heat the space and the hot water on the move.

Arrive at an aire and we were already toasty warm with hot water to boot.

A lot of Mercedes owners don’t realise they may have this diesel heater already fitted in the factory. If you don’t have one, you can add one.

Ive done these diesel upgrades 3 times now.

2001 sprinter 416cdi (no need for Mercedes’ visit)

2007 sprinter 518cdi (Frankia with heat exchanger I added into the Alde system)

2009 318cdi sprinter

 

[JinxJetJock]

It seems to me that many of the above folks don't drive vehicles with Euro 6 engines vehicles equipped with 'Stop-Start' or they would realise that this is not necessarily the case as such engines will stop instantly when the vehicle comes to a halt.

Stop/start tech is great all the time it's working. Only a question of time before someone is left stranded at a set of lights.

 

[Wee Bold Davy]

Start up, have a walk round to check all is in order, lower off E&P (need engine running for this), air up the rear end and drive off… doesn’t take 10 mins, equally it takes more than two mins!

Sounds just like us, we've also got a pre-flight checklist we go through

 

[Coolcats]

Why do people want to thrash the engine even when warm?

The engine in my car goes to 8,200 at the red line the shift light sequence is no lights then green then one, two, three amber and when I get to the limit it goes first red and then the final red

Pretty sure there is line in the film that says at 8,200 revs something special happens.....all I can say is I am a little kinder to the Motorhome engine but there are some diesels that are just as quick as a petrol one on track

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[sonar]

Potato up the exhaust will get him wondering what happened

Two one push a long way up the other just sticking out.
I know that works had it done to a few cars in our street a few years ago.

mine started then stopped. Then would not start again after that.

RAC. AA and a few other breakdown services all about 5e same time one one found out wha it was others soon managed to get it sorted .

 

[InvictaMoto]

Isn't the glow-plus a thing of the deep and distant past? I used to have to fire up the Mercedes 205 and 305 vans in the 90's and wait for the plug light on the dash to go off before starting it....

 

[Off da Grid]

Potato up the exhaust will get him wondering what happened

My Dad years ago made a tube that was blocked one end that he slipped over the end of the exhaust pipe, with the intention to chocke the engine if someone pinched his yellow chuvite.
After driving 3 miles back from my work place with it on because he forgot about it, it got thrown over the fence. Made I laugh still today.

 

[Ian Bosman]

I ask this question because on several occasions I have been parked next to a motorhome in which the driver insists on starting the engine and leaving it running for ten to fifteen minutes before he drives off. I remember this was a habit people had about twenty years ago, but with modern Diesel engines is it really necessary? It’s very annoying when they start up at 06.30am.

Engineering tolerances improved and better oil formulation makes such things a thing of the past and it is bad for the engine to “warm it up” plus so unfriendly to the environment. Do not do it! Drive off straight away is the fastest way to warm it up

 

[Ian Bosman]

Isn't the glow-plus a thing of the deep and distant past? I used to have to fire up the Mercedes 205 and 305 vans in the 90's and wait for the plug light on the dash to go off before starting it....

Still do on a very cold morning, my 2009 Ducato has the glow plug light on for a few seconds in the depth of winter

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[Beltie]

Start up, have a walk round to check all is in order, lower off E&P (need engine running for this), air up the rear end and drive off… doesn’t take 10 mins, equally it takes more than two mins!

Why do you need to have the engine running to raise the E&P jacks? I could imagine you might if your battery was on its last legs, but otherwise I can't see the point.
When Mick at SAP installed mine he told me just to turn the ignition on. I am inclined to trust him, and that's all I do. Never been a problem.

 

[Tio64]

Engineering tolerances improved and better oil formulation makes such things a thing of the past and it is bad for the engine to “warm it up” plus so unfriendly to the environment. Do not do it! Drive off straight away is the fastest way to warm it up

I thin this is the correct answer. Times have changed and materials have changed dramatically. Engines warm up more quickly with less wear by driving them. Obviously, we're not going to race off with foot to the floor, but if the vehicle is just driven normally the engine will warm up more quickly.

Leaving them idling is wasteful, anti-social, possibly illegal nowadays (or may become so) causes more pollution and does nothing for the engine or transmission.

The battery thing I don't get, they're going to charge up on the move anyway, surely? Modern alternators have clutches on the pulleys and don't even charge anyway until certain parameters are met.

 

[John Barrett]

My Mazda CX5 2.2 turbo diesel revs up on startup and dies down after a few seconds, thus validating the earlier views on turbo lubrication. I drive off straight away as suggested in the handbook. Love it...

 

[Landy Andy]

It’s part down to interpretation. Don‘t run a diesel at tick over, and some people think that 10 mins of tick over and it will explode now that they have read that. A cat or DPF on a tick over engine isn’t going to have any problems if it then goes for a proper run after. Its already working to put back the charge that has been used to start it in any case.

 

[Carpmart]

Why do you need to have the engine running to raise the E&P jacks? I could imagine you might if your battery was on its last legs, but otherwise I can't see the point.
When Mick at SAP installed mine he told me just to turn the ignition on. I am inclined to trust him, and that's all I do. Never been a problem.

Mine don’t work without the engine running.

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[slowcoach65]

Totally unnecessary.Not mentioned in the handbook.Reminds me when my dad used to leave the house 10mins before anyone else to "warm up the car" (and have a fag).Running with the choke on was never a good idea then with petrol engines and never heard it necessary for diesel.

Ah, the choke, the earliest form of cruise control!