There could be several things causing a knock in the top of your engine, most likely is that you are not using premium fuel.
Depends on the engine if its diesel the answer should be right, if its petrol it could as well be a whole bunch of other stuff.
You must be older than 18......that what Mercedes mean.
You must be older than 18......that what Mercedes mean.
Probley not depending on the age of the car. If its a slightly older model then it wont because the older range of Mercedes runs off the flintstones concept but there are little people (midgets) under the car carrying it so just toss a firework under there and they will either run like hell or die.
The year, make, model and engine size would help us help you. In older vehicles (pre-fuel injection) vapor lock was an issue.
Newer VW's (last 20 years), it doesn't really matter. Cheaper, low octane gas can cause knocking (early detonation), but the knock sensor will retard the car's ignition timing preventing knocking, but this will cause slightly poorer gas mileage. Thing is, the extra cost of the poor gas mileage isn't more expensive than the cost of higher octane gas, so it's pretty much a wash. Older VW's without knock sensors can have poorer gas mileage with cheap gasoline. This knocking will happen under hard acceleration. The knocking will be worse with higher compression (over 1: 8.5) engines like in the GTi, Cabriolet and Scirocco.
Bad plugs Wires, Distributor cap, Points if older model This is just a few things
the car needs air to power the locks and turning off the carso this means that you have a leak in your system that's normal for the older cars
Lumpy acceleration is often the case with diesel engines. If you own a newer Mercedes, you could check with different Mercedes tuning companies. What you need is a chip or powerbox, which will electronically adjust your engine in such a way that your engines power and torque goes up (through optimized engine computer), and your miles a gallon might also go up. I estimate that a power increase of about 10 to 30 horsepowers is possible. You can check out different Mercedes tuners, for example Brabus or Lorinser. If you own an older model, you can still search for a chip on the internet. If you can't find anything, an individual chip tuning might be possible through analysing your engine by a tuner. However, I'm not sure if the second suggestion is a realistic one.
On older 300ZX's equipped with a timing belt it will cause internal engine damage if the belt breaks as they are interference engines.
Older cheetahs.
cause they were getting older
The 4.7L does not directly interchange with any older engines.