Reving Up Car Engine Before Switching Off - Car Talk - Nairaland
Nairaland Forum / Nairaland / General / Car Talk / Reving Up Car Engine Before Switching Off (16934 Views)
Components To Avoid When Washing A Car Engine / When To Dump That Car Engine Before It Runs You Down / When To Change Your Car Engine Oil: The Mileage Way! (2) (3) (4)
| Reving Up Car Engine Before Switching Off by Ehido(m): 9:55am On Jan 29, 2013 |
My father has a habit of reving a car engine before parking infact growing up that's how we know he's back. This habit is still so embedded in him such that he does same to a highlander 2007 limited. When I told him to stop the practice he said it is necessary to remove the carbons from the engine. We had an argument about it but he still continues with this habit Guys is this practice advisable? If not what reasons can I give him to stop this? Thanks a lot. |
| Re: Reving Up Car Engine Before Switching Off by JUO(m): 4:19pm On Jan 29, 2013 |
bad idea, you are only killing the engine |
| Re: Reving Up Car Engine Before Switching Off by plendil: 6:02pm On Jan 29, 2013 |
lol! I have the same habit myself. rev to about 4000-5000rpms then switch off. not really sure why I do it. . .  |
| Re: Reving Up Car Engine Before Switching Off by Ehido(m): 9:40pm On Jan 29, 2013 |
Pls why is this a bad practice? |
| Re: Reving Up Car Engine Before Switching Off by Nobody: 12:37am On Jan 30, 2013 |
Ehido: Pls why is this a bad practice? An engine is meant to dissipate heat before shut down. Revving it up before shut down is doing the opposite. You let a non-turbo engine idle for at least 10 seconds, after a long, hard drive before shutting down. Oil galleries in the cylinder head and block will get restricted by carbonised oil, which is what happens to very hot oil, when the flow is suddenly interrupted by shutting down. As long as hot oil is flowing, it's safe. Suddenly shutting down a hot engine will halt the flow of oil, causing the temperature to rise even higher. Because it's now static, the risk of carbonising is higher. Over time, with repeated abuse, the carbonised oil increases, till the oil can no longer flow uninterrupted. This is when the engine oil low pressure warning illuminates. If this happens at high rpm, the engine will seize up, and destroy itself. If the road speed is high enough and seizure doesn't halt the engine, it'll certainly stop when a conrod breaks free of a piston, and punches a man-sized hol in the engine block. This is even more critical with a turbocharged engine. After a long drive, the correct thing to do is drive the last mile to destination at light throttle, so off-boost. And before shutting down the engine, you're meant to allow the engine to idle for at least a minute before switching off. The reason being - when you shut down a turbocharged engine after it's been making full boost (driven hard) the oil in the turbo gallery is extremely hot, in excess of 900 degrees celsius. When you suddenly interrupt the oil flow, the temperature in the turbo's hotside rises, and the stationary oil literally bakes, and becomes carbonised. In laymans terms, it goes hard, like wax. It will then cool in that state, and the next time you start the engine, the turbo oil gallery is blocked. Oil now has nowhere to go, and under pressure from the oil pump, will choose the path of least resistance - the turbo oil seal. It'll blow the seal, and the oil will be sucked into the intake, and literally blow through the exhaust as blue smoke. A 6 litre oil pan will be emptied in less than 5 minutes at idle in this state. This is one of the reasons Turbo Timers exist, for lazy people. It is set according to temperature. If the engine's really hot, you may switch off, but the timer will keep the engine running, for up to a minutet at idle, or more, depending on the settings. It will then shut down the engine when the turbo oil temperature has dropped to safe levels. Insurance companies don't like them though, and in some countries or states, it's actually illegal to have an engine running unattended. Don't rev your engine, before switching off! The only exceptions are Rotary engines, as used in Mazda and the Audi/NSU Ro80. 2 Likes |
| Re: Reving Up Car Engine Before Switching Off by Ehido(m): 10:48am On Jan 30, 2013 |
Thank you very much @Siena |
| Re: Reving Up Car Engine Before Switching Off by datola: 9:01pm On Jan 30, 2013 |
@Siena, thanks for clearing the air. Please, what about when starting the engine for the first time- in the morning to 'warm' the car, is it good to rev? |
| Re: Reving Up Car Engine Before Switching Off by Nobody: 9:52pm On Jan 30, 2013 |
datola: @Siena, thanks for clearing the air. You're not meant to "warm" a modern engine. You start, and drive off immediately, using moderate engine rpm until the oil has warmed up. Even leaving a cold engine to idle is bad. Most engine wear takes place when the engine is cold. The idea is to reduce the time the engine runs cold, i.e increase the warm-up period, and that means driving off as soon as the engine is started. 1 Like |
| Re: Reving Up Car Engine Before Switching Off by sandee575(f): 3:52pm On Feb 10, 2013 |
@ Sienna i think that practise of giving an engine the last rev stemmed from the days of carburetted engines, the idea being to leave maximum fuel in the float chamber against the next start. By doing so you would be precluding the need to pump fuel using the accelerator pedal during start. Carburettors were prone to problems arising from blocked jets, flow holes, shut off float valves and fuel evaporation especially following a prolonged parking time. 1 Like |
(1) (Reply)
Is It Safe To Clean MAF Sensor With Methylathed Spirit? / 7 Frequent Braking Problems You Should Never Ignore / Innoson Vehicles Will Take Over Africa – IVM Chairman, Chukwuma
(Go Up)
| Sections: politics (1) business autos (1) jobs (1) career education (1) romance computers phones travel sports fashion health religion celebs tv-movies music-radio literature webmasters programming techmarket Links: (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) Nairaland - Copyright © 2005 - 2024 Oluwaseun Osewa. All rights reserved. See How To Advertise. 21 |