I know how a diesel engine works compared to a gasoline engine, but what exactly makes the knocking noise from a diesel and why are some louder than others.
2007-12-02 06:02:11 · 6 answers · asked by JeffK 4 in Cars & Transportation ➔ Other - Cars & Transportation
I did own a 2005 Ford F250 with a 6.0 and the salesman told me it's quieter than the old 7.3 diesels becuase of the injector and pump design. Not sure if I believe a salesman, so what was he talking about?
2007-12-02 06:14:02 · update #1
Most of these answers are close but the term hot, heated, or superheated air is all wrong. Diesels use compression in place of spark plugs. Most higher horsepower diesels use intercoolers to help cool the intake air. The knock is the high pressure injectors and compression.
2007-12-02 07:03:27 · answer #1 · answered by Scot V 1 · 2⤊ 0⤋
Diesel Knock
2016-11-11 05:29:17 · answer #2 · answered by Anonymous · 0⤊ 0⤋
This Site Might Help You.
RE:
What makes diesel engines knock?
I know how a diesel engine works compared to a gasoline engine, but what exactly makes the knocking noise from a diesel and why are some louder than others.
2015-08-12 20:05:00 · answer #3 · answered by Anonymous · 0⤊ 0⤋
There are a few differences between the two engine types. In order to explain it's probably best to think of them in terms of the engine, rather than the fuel. A compression ignition engine (you know it as a diesel engine) takes air into the cylinder where it is compressed. The fuel is then injected into this high-pressure (and therefore very hot) air. At this point the fuel ignites and produces power. A spark ignition (petrol) engine doesn't take just air into the cylinder, but a combination of air and fuel (also known homogeneous charge) are taken into the cylinder then compressed. A spark is then used to ignite the fuel/air mix which in turn produces the power. From this point both CI and SI engines work in the same way, expelling the exhaust gasses and preparing for the next cycle. To cloud the issue, SI engines aren't only run on petrol but can also be run on Hydrogen, Ethanol, LPG, and Methanol (amongst other things). There are also some new "Petrol" engines that use compression ignition (i.e. they work in the same way as diesel engines, but run on petrol). These are known as Gasoline Direct Injection (GDi).
2016-03-14 01:00:28 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Diesel engines compress hot air in the combustion chamber and inject fuel to ignite forcing the piston down at more than three times the pressure in a gas engine,there for they make more noise,the design of each from year to year.
Average life of a diesel is 300,000 plus miles W/ gas it's 150,000 and their dead.
2007-12-02 06:24:11 · answer #5 · answered by Anonymous · 0⤊ 0⤋
The knock comes from the detonation (explosion of the fuel-air charge, and is caused by excessively high combustion chamber temperatures) in the cylinders. Detonation is bad in regular gasoline engines but is what makes diesel engines work. I don't usually do diesel engines so this is just what my engine rebuild instructor told me...
2007-12-02 06:09:05 · answer #6 · answered by sndprssr 3 · 0⤊ 0⤋
Ignition of the diesel is through electrostatic head arching igniting the diesel fuel. It causes irregular ignition of the fuel at lower RPM's when you are not building up as much chamber pressure. which in turn causes the knocking noise.
At higher RPM's more air is rammed into the cylinders by the turbo chargers or super chargers increasing chamber pressure and giving a smoother ignition of your fuel.
2007-12-02 06:17:17 · answer #7 · answered by JUAN FRAN$$$ 7 · 1⤊ 0⤋