leaving on idle - Saxperience

adamm · 17th December 2009, 18:41

hey just wondered a couple things really is it bad to leave an engine idling to long and what is too long?? also say if i was to leave my car idling for 10 mins would this compensate the fuel it uses to start up i have a mk 2 vtr 90bhp version with induction kit and exhaust. just curious

bald24 · 17th December 2009, 18:42

Wont damage anything - but will be burning fuel yeah.

adamm · 17th December 2009, 18:46

yeah so you could really leave it idling for say 10 hours??
and the second question is say if i was picking someone up and i was to be waiting for say 10 mins would it be worth turning the engine off as the fuel used while on idle wouldnt be much more than having to start the engine back up again???

maddison_vts · 17th December 2009, 18:53

shouldn't do any harm at all unless it was quite a tuned engine, they can get bore wash if left idling for too long i beleive.

my friend left his punto gt turbo idling for over 4 hours because his turbo timer decided to not turn the car off he got back and the car was still running, caused no issues at all.

adamm · 17th December 2009, 18:57

cool just curious if it was bad for the engine in anyway and as for the other question???

maddison_vts · 17th December 2009, 19:03

well if its going to be as long as 10 minutes i'd turn it off because i'd have thought it would use more fuel in 10 mins of running to a start up.

if its a case of 2 minutes just leave it running.

the difference in fuel is so small i wouldn't worry about it.

adamm · 17th December 2009, 19:17

yeah true just im a fussy bugger and it niggles me thinking if it uses more fuel to leave it running i hate turning my car off then a minute later turning it on dont ask why just bother me. but yet when im driving i dont care what fuel im using.

adamm · 17th December 2009, 19:18

how much fuel would it roughly use on my car vtr with exhaust and induction kit on idle say for an hour then? would it even be a noticable amount?

Mr_P · 17th December 2009, 19:26

Only thing I can think of is that it's gonna get hot. You'll just have the fan moving air through the rad/engine bay so average bay temps will be higher I'd imagine. But as long as the fan works you're not gonna have any problems.

adamm · 17th December 2009, 19:28

yeah i guessed it would get hot. just wondered if it was generally bad for the engine.

Mr_P · 17th December 2009, 19:31

I'd imagine the same revs constantly would be better for engine wear than what accelerating and decelerating are going to cause. So probably less painful for an engine. Just the heat really that would cause a problem, but if kept cold it should be fine.

adamm · 17th December 2009, 19:39

yeaahh cool.

Barry123 · 17th December 2009, 21:26

In terms of fuel usage I have no idea where this myth about the engine gobbling mega amounts of fuel during the actual start up. You need to leave it idling for 10, 5 or even 2 mins. So if you need to turn it off then feel free. The only beef is the low oil pressure at idle but it won't do anything significant over a mediumish period of time.
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Meto · 17th December 2009, 21:35

I have read if the car idles for long amounts you can get a buildup on the spark plugs, but i dont think it would do too much damage.

craigy2703 · 17th December 2009, 21:45

i dont think it would harm anything to be honest a quick blast down a b road would clear any gunk on the sparkplugs

VTR_Craig · 17th December 2009, 23:26

Dont quote me but i have been told that if your going to be sat idling for more than 10 seconds then you will use more fuel than if you switched the engine off and started up again.

turning engine off at railway lines ftw

stingray1987 · 17th December 2009, 23:30

Quote:

Originally Posted by VTR_Craig

Dont quote me but i have been told that if your going to be sat idling for more than 10 seconds then you will use more fuel than if you switched the engine off and started up again.

turning engine off at railway lines ftw

ite save you a penny or 2 a week on petrol but u will soon get through starter motors and you will defo blow other things along the way.
i would not recomend doing this every time u stop for more than 10seconds lol

Barry123 · 17th December 2009, 23:51

Quote:

Originally Posted by stingray1987

ite save you a penny or 2 a week on petrol but u will soon get through starter motors and you will defo blow other things along the way.
i would not recomend doing this every time u stop for more than 10seconds lol

if it's a warm engine then there is little stress on the starter motor anyway so I doubt you'd need to worry!

adamm · 18th December 2009, 11:41

ohhh well sometimes ile leave it idling for like half hour when im out in the cold to keep warm an idea what sort of fuel this uses up?

leighk18 · 18th December 2009, 11:47

really would not worry about how much it uses mate not going to be a lot either way