Reving before turning car off

[Christophe]

I know some people rev the car slightly as they turn the car off. Im sure i read somewhere it clears the system or am i completly wrong and is it just chavy?

 

[edde]

Its old school mechanics they did it as it pushed a load of oil round the engine just beofre its switched off so its lubricated for next time.

No point though these days.

 

[Maxx]

I sometimes do it if the car starts idling funny but thats all lol

 

[glenwatt]

I do know it's bad practice if you've got a turbo fitted.

Due to high spin rates and lack of oil flow.....

 

[SOHROB]

only do it if you have an rx8 as if you dont the engines flood

 

[jack_davey]

Its old school mechanics they did it as it pushed a load of oil round the engine just beofre its switched off so its lubricated for next time.

No point though these days.

I can see the reasoning behind that, but its actually bollucks, once the engine is switched off, the oil pump stops running anyway, so the oil just drains down into the sump as it would if you just switched it off at idle.
Ive heard the theory that people used to do it on carb engines so that it left some fuel in the inlet for a cold start the next morning, however fuel evapourates at room temp anyway, so by the next morning it would be gone, if it had not been sucked out by the pistons as the crank was slowing down.

 

[black kro]

pointless and potentially stupid (as said) with a turbo!

 

[Christopher]

pointless with modern engines tbh

potentially damaging for a turbo engine too iirc

 

[ianeire]

Chavtastic.

 

[xcore]

your ment to leave the engine idleing for 30ish secs before switching off with a turbo arnt you?

 

[ianeire]

It depends on how hard you've run the car and what state of tune that the car is in.

It's 'good practice' but not necessary on standard turbo cars in standard guise.

 

[Weeman]

With a full fat turbo yes, the sort of turbo that comes with my golf not so much.

 

[j6 pkp]

they usually say to run a turbo engine after a long drive for a few minutes, or drive the last couple of miles at littl or no boost i think.
no point revving a n/a engine imo.

 

[mike F1 20]

i must be one of the pointless chav's then lol

 

[GordonD]

Did an internet search.

Found a LOT of sites that said don't do this. Don't rev the engine then turn it off. They said it was a silly idea that dated back to carby days, that people thought it "primed" the carb, making it easier to start the next time. But that what it actually did was send petrol into the cylinders that washed the oil off the cylinder walls and did harm.

Then I found one that specifically said to do it. And it was the instruction manual from a car manufacturer, Radical, for its SR8 engine. Its in the instructions for warming the car up in the pits before a day's racing. They say warm up the engine until water temperature gets to 50C, rev the engine to 6,000 rpm, then turn it off. No explanation is offered as to why. The implication is that a quick burst clears the plugs - it is a race engine not a road engine - and makes it more likely it'll start easily and quickly when you're ready to fire it up and go out onto the track. And having driven cars that idle roughly and foul their plugs easily because they're highly tuned that makes sense.

 

[jack_davey]

Yes thats true you should leave a turbo car running for a while before turning it off, so that you give the impeller time to slow down, because once you shut the engine off, it cuts the oil feed to the turbo and then after a hard drive it leaves the turbo spinning with no lubrication, causing the turbo spindle to wear and in some cases sieze! So revving a turbo car before turning it off is even worse!
Some modern engines have an electric oil pump that runs for a few minutes after switching off the engine so it keeps the turbo lubricated.

 

[Ian_182]

I still find it quite funny hearing the local chavs doing this

 

[bmh.01]

Yes thats true you should leave a turbo car running for a while before turning it off, so that you give the impeller time to slow down, because once you shut the engine off, it cuts the oil feed to the turbo and then after a hard drive it leaves the turbo spinning with no lubrication, causing the turbo spindle to wear and in some cases sieze! So revving a turbo car before turning it off is even worse!
Some modern engines have an electric oil pump that runs for a few minutes after switching off the engine so it keeps the turbo lubricated.

Its more so to do with the oil coking up due to the heat in the turbo (bearings specifically) after you've given it a beasting. Thats why you don't rev it not why you leave it running.

 

[mrgund]

Can't say i have ever done this! i leave it idling for 30 seconds or so after a long drive but never rev it!

 

[Ollie82.]

Blipping the gas when starting from cold yes...when switching it off...i've never heard of!

 

[fUbAr]

my neighbours would soon get fucked off with me if i did that. My car's not quiet.

 

[Pep]

I always give the car a few second to idle once I stop, nothing special just while I sort my seatbelt out and put phone on pocket and take face plate off my stereo.

I also give it a minute or so when starting it up in the morning to just level the idle out a bit so its ready to drive, didnt do this on my first clio and that was dog rough, my new one is smooth as anything and idles perfectly, but I dont drive this one like I've stolen it so it might help, plus the 1/3 mileage and service history might help!

 

[Jaff]

the clio hand book specifically tells you not to blip the throttle when starting or stopping the igntion, doesnt say what but tells you not to.

 

[Ollie82.]

Well i've learnt that blipping the throttle when cold splashes the oil up from the sump. Never done my car any harm.

 

[MarkCup]

I used to do this, but stopped, when I exahust + decatted it.

 

[Ollie82.]

By request of the neighbours i'd imagine!

 

[beavis]

Ive heard the theory that people used to do it on carb engines so that it left some fuel in the inlet for a cold start the next morning

Dam I must be old, or at least I've crappy old cars in the past. It's exactly what I used to do with my Triumph Toledo and I swear it made it easier to restart the next time. I still do it a little (3k rpm) out of habbit, but I'll try and break it before I get labelled a chav

 

[kully]

I do it , but out of habbit and really dont know why .

 

[rich19]

i think the chavs got it from vin diesel in fast and furious coasting in revving his car!

i do the opposite if i`ve been pushing the car i leave it ideling on the drive for a minute, i do the same before i leave for work

its habit for me now and it probably makes no difference

 

[Iridium]

I do sometimes, because my car pops on the over run and it sounds cool and I'm a child

Dan

 

[TeZ]

redline it then turn it off for the chavtastic blow back.

 

[willcrook]

I say bye bye to my car whenever I get out of it, and thats the cars way of saying bye back to me xxxx <3

 

[Karlos182]

You should never do this in a regular car with a cat fitted.

It floods the delicate membrane in the cat with unburnt fuel, which damages the cat.

 

[Coyote]

I do it, but only because my dad used to do it when i was a kid. Bad habbits.

 

[rs250nut]

You can also wash the bores in certian cases, mainly with turbos that have had a fuelling increase.

 

[foxon]

i only slightly blip the throttle when startin her up when its cold (only really drive it at night) never do it b4 i turn it off, but i do leave it idlein for about 30 seconds.