[ezrabmw]

Hello everyone, I need some assistance with my car issue. For the past few months, my car has been exhibiting a slight rattle upon starting, which usually subsides after some time. Additionally, I've noticed intermittent jerking during cold starts, occurring roughly every 2-3 weeks for a few seconds. Recently, after filling up with Shell 93 + Nitro, my car struggled to turn on during the second attempt, and the engine was shaking noticeably. After a few minutes of driving, the issue seemed to resolve itself.

Seeking advice, a mechanic suggested using a fuel system cleaner, considering the car's relatively low mileage. I followed the recommendation, adding the cleaner to a half tank, running it almost empty, and then refilling the tank over the weekend. Surprisingly, the car did not shake initially, but when I came to a red light in drive, it attempted to shut off twice. The RPM dropped significantly, almost leading to a stall, accompanied by a distinct rattling noise (different from previous instances) occurring twice before stopping.

I would greatly appreciate any insights or assistance you can provide.

[clegg]

Add Techron fuel system cleaner (black container)at almost empty tank and refill. Also on your shell refuel you may have filled with a bad batch of fuel.

[jagyro]

Injector cleaner really wont do much if anything. If its a injector, under hard accel the car will throw a code. Also during startup if its shaking and crap its possibly the injector leaking which is a common issue. Basically the injector will drip fuel into the combustion camber causing a shaky startup until it burns it all off. The only way to clean it yourself is hooking a battery up to it with a switch to throw only cleaner through it till its fully cleared out. Or you can get a cleaner off amazon that does just that.

[gasoline]

Originally Posted by ezrabmw

Hello everyone, I need some assistance with my car issue. For the past few months, my car has been exhibiting a slight rattle upon starting, which usually subsides after some time. Additionally, I've noticed intermittent jerking during cold starts, occurring roughly every 2-3 weeks for a few seconds. Recently, after filling up with Shell 93 + Nitro, my car struggled to turn on during the second attempt, and the engine was shaking noticeably. After a few minutes of driving, the issue seemed to resolve itself.

Seeking advice, a mechanic suggested using a fuel system cleaner, considering the car's relatively low mileage. I followed the recommendation, adding the cleaner to a half tank, running it almost empty, and then refilling the tank over the weekend. Surprisingly, the car did not shake initially, but when I came to a red light in drive, it attempted to shut off twice. The RPM dropped significantly, almost leading to a stall, accompanied by a distinct rattling noise (different from previous instances) occurring twice before stopping.

I would greatly appreciate any insights or assistance you can provide.

Hi,
By means of jerking, do you feel a “wavy acceleration” when you press the gas pedal; as if the car accelerates strong first, then relaxes, again accelerates strong…and so on.

I had this kind of issue on my 530i and I clearly saw that the torque was fluctuating on sports gauge screens.
If you also feel a similar issue; my problem was solved by replacing “vanos actuators”.