Parking With Ac On For Long Time

[hatharasinghe]

Dear all is it not good for the engine to park the car and AC on for longtime such as 2hrs while engine running in parking mode if any damages to engine or it only the cost of fuel pls explain

thanks.

[MrCat]

'MrCat',

Can you give a answer for using a car engine at low rpm without running on the road.(The effects of prolonged idling on modern motor car engines)

Sylvi Wijesinghe.

The problem is Sylvi, I have no technical knowledge or experience on the subject. That`s why i`ve been keeping an eye on this thread. I`ve read arguments for and against idling mainly on diesel engines (where most say it`s OK), but am clueless when it comes to actual technical facts, specially for gasoline engines.

Anyways, big applause for miniace for the clarification. One question mate, is this issue the same with modern gasoline engines? i mean shouldn't the ECU be reading the core temperature and doing some adjustments accordingly as to prevent plug fouling?

[maersk]

Ayyo Sylvi mate..I am disappointed.

Anyways since the game is over after Sylvi throwing the towel without an attempt, let me tell all why prolonged closed throttle running is bad for spark plugs,

Prolong and extensive idle running prevent spark plug core temperature running inadequate .Only when running above 1000 RPM the core temperature reaches healthy temps and hot enough to activate the lead scavenger agents in fuel thus preventing lead salt deposit formation on plugs and exhaust valve stems.This is in simple terms known as the plug fouling. Plug fouling happens due to many reasons and prolong running at idle is one main cause.

Hope all doubts are cleared.

MINIACE

Also very common in large engines using heavy oil if running with less load/RPM for longer periods. Less RPM/load running is really a pain for engineers as lot of cleaning inside scavenge spaces necessary & fail to do may result in fire inside scavenge spaces. I know there are no spark plugs in large engines but inadequate temperature is the root cause here.

[miniace]

Honorable Miniace,

I agree to your point. Please note after two or more hours stop we start moving again at 40 MPH, or maximum speed allowed to move according to said vehicles speed on high ways. Most high ways show your speed with allowed maximum speed. Not in Srilanka,then will that will not help to the already deposit formed plugs and valves to come back to serviceable condition.

Sylvi Wijesinghe.

Running at high revvs 8000 plus up wont help .Thats not the way to heal a fouled plug or an effected valve stem.That will never work...basics mate...basics!

MINIACE

[miniace]

Anyways, big applause for miniace for the clarification. One question mate, is this issue the same with modern gasoline engines? i mean shouldn't the ECU be reading the core temperature and doing some adjustments accordingly as to prevent plug fouling?

Its same with modern engines, both Gas and Diesel. Or maybe bit serious and sensitive than old ones.

MINIACE

[Sylvi]

Also very common in large engines using heavy oil if running with less load/RPM for longer periods. Less RPM/load running is really a pain for engineers as lot of cleaning inside scavenge spaces necessary & fail to do may result in fire inside scavenge spaces. I know there are no spark plugs in large engines but inadequate temperature is the root cause here.

'maersk',

There are Generator engines some run at 900 RPM most of them are dry sump engines. Some are direct coupled some run with about 6 belts generator running with 1500 RPM. They run for continuously for few days without any problems. only first service at 500 hours there after every 2000 hours. until 10000 hours.

If I am not mistaken marine engines also run at very low RPM.

Sylvi Wijesinghe.

[Sylvi]

Running at high revvs 8000 plus up wont help .Thats not the way to heal a fouled plug or an effected valve stem.That will never work...basics mate...basics!

MINIACE

MINIACE,

OK I agree with you. Can you give me a web link about the RPM of engines, Automobile and Industrial. I Googled but could not find correct one.

Sylvi Wijesinghe

[miniace]

MINIACE,

OK I agree with you. Can you give me a web link about the RPM of engines, Automobile and Industrial. I Googled but could not find correct one.

Sylvi Wijesinghe

Name of the game.."for me to tell you..and you to find out " Rather refer your old books and note books mate...thats what im doing most of the time.Those are the basics taught at automobile school.

MINIACE

[fonfe]

Not being funny here but worrying about core temperature at idle is frankly a waste of time. Worrying about fouled plugs..........are you living in the 80s? Yes as a general rule of thumb plugs will require changing much much more often on a carb'd engine than on an efi engine but this has very little to do with "core temps" its much much more to do with incorrect AFR, which should be very correct at idle. Carb'd engines have very little fueling control whereas an efi engine has lots. Car runs rich - plugs get fouled............ If anything i would be more concerned with the fuel in lanka, in simple terms its CRAP! 90ron???? Best fuel ive seen in galle so far is 95 and thats still crap! Once this country ups the fuel quality everyone will have less issues with their engines, better bang for buck and far better emissions.

My comment about the 80's is because back in the day a an engine was designed to do on average 80-100k (miles) before needing a rebuild, spark plugs were also changed at every service interval. A engine from the 90's is expected to do double that with plugs changed every few services. Eg. 4.4 lm range rover (BMW m62 engine) they are only done twice for as long as the service sheet goes for! A modern ford gets them every 25k miles and to be honest they very rarely won't run if they aren't changed.

The time deadline for Sylvi think was rather unfair, from what I've read the dude seems to know his stuff that he comments on but like me he can't check in on a forum every single day because he has other things to do.

[fonfe]

Not being funny here but worrying about core temperature at idle is frankly a waste of time. Worrying about fouled plugs..........are you living in the 80s? Yes as a general rule of thumb plugs will require changing much much more often on a carb'd engine than on an efi engine but this has very little to do with "core temps" its much much more to do with incorrect AFR, which should be very correct at idle. Carb'd engines have very little fueling control whereas an efi engine has lots. Car runs rich - plugs get fouled............ If anything i would be more concerned with the fuel in lanka, in simple terms its CRAP! 90ron???? Best fuel ive seen in galle so far is 95 and thats still crap! Once this country ups the fuel quality everyone will have less issues with their engines, better bang for buck and far better emissions.

My comment about the 80's is because back in the day a an engine was designed to do on average 80-100k (miles) before needing a rebuild, spark plugs were also changed at every service interval. A engine from the 90's is expected to do double that with plugs changed every few services. Eg. 4.4 lm range rover (BMW m62 engine) they are only done twice for as long as the service sheet goes for! A modern ford gets them every 25k miles and to be honest they very rarely won't run if they aren't changed.

The time deadline for Sylvi think was rather unfair, from what I've read the dude seems to know his stuff that he comments on but like me he can't check in on a forum every single day because he has other things to do.

[miniace]

Not being funny here but worrying about core temperature at idle is frankly a waste of time. Worrying about fouled plugs..........are you living in the 80s? Yes as a general rule of thumb plugs will require changing much much more often on a carb'd engine than on an efi engine but this has very little to do with "core temps" its much much more to do with incorrect AFR, which should be very correct at idle. Carb'd engines have very little fueling control whereas an efi engine has lots. Car runs rich - plugs get fouled............ If anything i would be more concerned with the fuel in lanka, in simple terms its CRAP! 90ron???? Best fuel ive seen in galle so far is 95 and thats still crap! Once this country ups the fuel quality everyone will have less issues with their engines, better bang for buck and far better emissions.

My comment about the 80's is because back in the day a an engine was designed to do on average 80-100k (miles) before needing a rebuild, spark plugs were also changed at every service interval. A engine from the 90's is expected to do double that with plugs changed every few services. Eg. 4.4 lm range rover (BMW m62 engine) they are only done twice for as long as the service sheet goes for! A modern ford gets them every 25k miles and to be honest they very rarely won't run if they aren't changed.

The time deadline for Sylvi think was rather unfair, from what I've read the dude seems to know his stuff that he comments on but like me he can't check in on a forum every single day because he has other things to do.

Fonfe dude the game we played here, to educate people and encourage members to learn more than being simple reading/listening statutes. Read back and realize yourself.

On the concern of core temperatures of plugs it contributes when calculate the overall damage to the system no matter carb or Efi especially in a country like SL where the total sulphur % wt stands 0.10 and lead contents stand at Pb /mgl 13ppm irrespective of the RON+MON/2 figure. whoever who treat this lightly opens a door for a chain reaction.

Members here are so enthusiastic yet enjoying the spoon feed. Just open up a few old topics and see. Sorry for being a little sarcastic but im not surprised if I see somebody opens up a thread and ask which side the wheel nuts loosened. Technology is so good..you 'd know everything by just pressing few buttons on google, the matter here ,who does it for you!

MINIACE

[miniace]

The time deadline for Sylvi think was rather unfair, from what I've read the dude seems to know his stuff that he comments on but like me he can't check in on a forum every single day because he has other things to do.

Sylvi being a very enthusiastic member willing to talk about almost everything, deserved a good reward. Especially from me. Thats why only he was selected with a fair amount of time, sadly he decided to give up the run for a good aviation trophy even without attempting (reasons unknown and surely that is dissapointing).Read Sylvis reply for that please.Thats more like refusing a present.Please dont be unreasonable and biased on analyzing.

MINIACE

[Sylvi]

Sylvi being a very enthusiastic member willing to talk about almost everything, deserved a good reward. Especially from me. Thats why only he was selected with a fair amount of time, sadly he decided to give up the run for a good aviation trophy even without attempting (reasons unknown and surely that is dissapointing).Read Sylvis reply for that please.Thats more like refusing a present.Please dont be unreasonable and biased on analyzing.

MINIACE

'miniace',

Thank you for your comments, I mostly write about Electrical problems, That subject was my specialty. Because I started with Electrical winding. No Electrical maintenance person will be a good technician if he does not know his fitting of units. I later picked up other things of engine repairs Lathe work tool making,thanks to my parents for 1st class country for sending me abroad during 1960s. Thereby I became a more polished man During 1965 to 1979 era I did plenty of modifications to automobiles as well as other Industrial units for them to be in usable running condition. Because that era was a closed era with very few imports to our country.

I am a old school Technician, still active in Automobile industry. I do not want to mention all modifications. I have done in my life and younger generation is not interested in those. Today is plug and play, if any ting is not working throw and fix a new part.

No one in this world will be a perfect man. We all will do mistakes in our life, those will be lessons for future.

Sylvi Wijesinghe.

[miniace]

'miniace',

Thank you for your comments, I mostly write about Electrical problems, That subject was my specialty. Because I started with Electrical winding. No Electrical maintenance person will be a good technician if he does not know his fitting of units. I later picked up other things of engine repairs Lathe work tool making,thanks to my parents for 1st class country for sending me abroad during 1960s. Thereby I became a more polished man During 1965 to 1979 era I did plenty of modifications to automobiles as well as other Industrial units for them to be in usable running condition. Because that era was a closed era with very few imports to our country.

I am a old school Technician, still active in Automobile industry. I do not want to mention all modifications. I have done in my life and younger generation is not interested in those. Today is plug and play, if any ting is not working throw and fix a new part.

No one in this world will be a perfect man. We all will do mistakes in our life, those will be lessons for future.

Sylvi Wijesinghe.

Easy mate! point is taken..happy to know that you from the 'Classic Era" .

On the subject of running idle,I guess members are aware of the bad effects now...must take a break from this thread.......THE END.

MINIACE

[fonfe]

Most people on here just google answers?

Recipe for disaster there lads, lots of very incorrect info can be found on google

[CARBON B4]

I for one Google just about anything from finding a telephone number of a restaurant to buying a phone, car, look up medication...

[fonfe]

Be very carefull in that case mate, lots of incorrect info on all sorts of things as info is not regulated especially on car forums

Looking up phone numbers and general things won't cause you any issues but I've had customers bring their cars to me in the past with some shocking things done and when asked why did you do this the reply has been "the Internet said to"

[CARBON B4]

Yeah... sometimes navigating the www can be difficult with all the garbage out there. But you also need common sense to figure out whats right from wrong.

[smiling cars]

it is ok but not to forget to keep your eye on temp gauge, bcoz AC compressor and AC condensor getting heat coz there no ventilation. About talking fuel consumption

engine starting> idling speed (firing interval is too long)>high speed cruising>low speed cruising

[Cyclist]

So we are back to square one.! Is it good to keep engine while A/C on while parked or not?

I think, idling for long time surely puts stress the cooling system as natural flow of air is not available as if it was when moving.

And idling while AC compressor is engaged and ac fan / blower unit consuming lot of power should be putting stress on the electrical system too ,because less electricity is generated and lot consumed.

in that sense , idling while AC turned on is bad for engine.

Edited December 12, 2011 by Cyclist

[Sylvi]

I think, idling for long time surely puts stress the cooling system as natural flow of air is not available as if it was when moving.

And idling while AC compressor is engaged and ac fan / blower unit consuming lot of power should be putting stress on the electrical system too ,because less electricity is generated and lot consumed.

in that sense , idling while AC turned on is bad for engine.

'Cyclist',

As for my knowledge moment you on your AC engine rev up alternator ( Automatic Voltage regulator) is made to compensate the voltage drop of the battery to come back to required Voltage, there by the increased draw of current from the battery will be compensated and battery will be charged to be in good condition

I agree to the vehicle is not moving, there by no extra air is not circulated around the radiator to keep the efficiency of the cooling of the radiator.

This is one reason most new vehicles have electrically operated radiator fans for cooling of the engine. like the A/C cooling fan out side.

Only thing is the consumption of fuel will go up. I have had used gasoline used engines parking for few hours with A/C and other equipment on there was no problem to the engine.

There are industrial engines stationary run with only radiator cooling fans, separate oil coolers.with maximum loads what they are permitted to handle.

Above is my experience.

Sylvi Wijesinghe.

[Cyclist]

Sylvi, thanks for your post.

and I found some people are very serious about the idling a car

http://www.thehcf.org/antiidlingprimer.html

'Cyclist',

As for my knowledge moment you on your AC engine rev up alternator ( Automatic Voltage regulator) is made to compensate the voltage drop of the battery to come back to required Voltage, there by the increased draw of current from the battery will be compensated and battery will be charged to be in good condition

I agree to the vehicle is not moving, there by no extra air is not circulated around the radiator to keep the efficiency of the cooling of the radiator.

This is one reason most new vehicles have electrically operated radiator fans for cooling of the engine. like the A/C cooling fan out side.

Only thing is the consumption of fuel will go up. I have had used gasoline used engines parking for few hours with A/C and other equipment on there was no problem to the engine.

There are industrial engines stationary run with only radiator cooling fans, separate oil coolers.with maximum loads what they are permitted to handle.

Above is my experience.

Sylvi Wijesinghe.

[Sylvi]

Sylvi, thanks for your post.

and I found some people are very serious about the idling a car

http://www.thehcf.or...lingprimer.html

Cycilist,

First of all thank you for taking trouble to spend your time to discuss about this subject. So that all A/l members will be benefited.

I read that article. that says lot on negative side of idling. Actually we are not idling the engine when we use A/c the engine speed up.

When A/C is on the engine do not idle, it speeds up to take the load of the compressor and alternator. that may be some percentage of the power of the engine.

if you drive the car on Colombo traffic with A/C ON average car will drop to 6 to 10 KM/L, if you do the same run without A/C, then your fuel consume will be much less it can be 8 to10. depending on the traffic.

For example you cannot fix a A/C to a D*MO batta then the engine will have problems. No pulling power. D*MO do not recommend the A/C to be fitted.

Car this can be noticed you travel at 30 KM/H and on the A/c, then definitely the speed will come down and have to accelerate little more to keep the same speed.

This indicates the engine needs some more fuel to compensate for the extra A/C load, and for the A/C current load.

Above is not tested by me. I have used non A/C Vehicles and A/C Vehicles. must do a test before coming to a conclusion.

When I had my training abroad some engines never stop during the day/night they carry big loads they stop for loading and unloading engine running slow. Until that is over, idle for another 1 hour or so again run with a load for few miles stop until the load is unloaded or loaded. During summer the driver keep the A/C on, heater fan on during winter. those Hunslet engines never had any problems

I wrote about A/C load on heavy loaded engines which they are used for short runs.

Most high capacity generator engines do have engine running hour meters. We do service them accordingly for number of hours they run.

In some engines their running hours for a year will be few hours but they run at 1500 RPM. to get the correct frequency, Load depending on production capacity.

On the above subject I must do a study of fuel consumption and engine problems to follow running at idling speeds with A/C on. specially on automobiles.

Sylvi Wijesinghe.

[Cyclist]

Cycilist,

First of all thank you for taking trouble to spend your time to discuss about this subject. So that all A/l members will be benefited.

I read that article. that says lot on negative side of idling. Actually we are not idling the engine when we use A/c the engine speed up.

When A/C is on the engine do not idle, it speeds up to take the load of the compressor and alternator. that may be some percentage of the power of the engine.

if you drive the car on Colombo traffic with A/C ON average car will drop to 6 to 10 KM/L, if you do the same run without A/C, then your fuel consume will be much less it can be 8 to10. depending on the traffic.

For example you cannot fix a A/C to a D*MO batta then the engine will have problems. No pulling power. D*MO do not recommend the A/C to be fitted.

Car this can be noticed you travel at 30 KM/H and on the A/c, then definitely the speed will come down and have to accelerate little more to keep the same speed.

This indicates the engine needs some more fuel to compensate for the extra A/C load, and for the A/C current load.

Above is not tested by me. I have used non A/C Vehicles and A/C Vehicles. must do a test before coming to a conclusion.

When I had my training abroad some engines never stop during the day/night they carry big loads they stop for loading and unloading engine running slow. Until that is over, idle for another 1 hour or so again run with a load for few miles stop until the load is unloaded or loaded. During summer the driver keep the A/C on, heater fan on during winter. those Hunslet engines never had any problems

I wrote about A/C load on heavy loaded engines which they are used for short runs.

Most high capacity generator engines do have engine running hour meters. We do service them accordingly for number of hours they run.

In some engines their running hours for a year will be few hours but they run at 1500 RPM. to get the correct frequency, Load depending on production capacity.

On the above subject I must do a study of fuel consumption and engine problems to follow running at idling speeds with A/C on. specially on automobiles.

Sylvi Wijesinghe.

Thanks for your views again Sylvi, I now think my stand about idling with AC has no any solid evidence to say it harms an engine.

About the link I posted above which is not that relevant to this topic, it says how bad is idling the engines, but even my dad has a different view ,

he keeps the diesel van in idle for 5-10 in every morning before pulling out to get it warmed up and never stops the engine casual stops along the road( 10 mins shopping etc).

What do you think about that? Is there any real advantage by warming up the engine in the idle in the morning ?

[CARBON B4]

Its good to let the engine run for a few mnts before driving off, especially in the morning.

I also avoid switching off the engine during short stops, letting it run is better as I heard somewhere that start ups contribute a lot to engine wear.

[CARBON B4]

Its a interesting question.....

One argument against this is if when the car is moving both the a/c condenser and the radiator gets some natural cooling. Ans since this is not there the fans may have to work a little harder, but since the engine is on idle the rpm is under 1, which means its generating only small amount of power just to keep it without stalling.

So we have a situ where the power is less, but the demand for power is more from the fans and blower. You could argue that car is intelligent enough to balance this by increasing the rpm when needed but I somewhow feel this is not good, as the ac fan is always switching on and off .

But seriously why would anyone want to keep it running for 2 hours, you are just wasting the petrol and also polluting the environment. Btw you should not do this in a closed car park. I always try to take a calculated guess. If its a case where the wife has to go in to a cloths shop, best thing to do is to find a nice shaddy spot and switch off that engine..