[G30Dave]

Hello, I recently picked up a 17 540i M sport. It seems to have a rough idle and vibration at start up and when engine temp is cold and I was wondering if this is normal? Almost resembles a bad engine mount. There’s also a slight vibration when cold. Dealer had installed new front tires before I purchased. Thanks,
Dave

[GeorgeI]

I can't say with absolute certainty, but it sounds very much like it's missing on one of more cylinders. Probably a bad spark plug. Are you getting a CEL?

[Ibra N]

I had such issue like this with my 18 530i
took it to dealer and they manage to fix that issue now the vibration is very minimal if not gone. btw it wasn't something rough but its noticeable

[742002tii]

Originally Posted by GeorgeI

I can't say with absolute certainty, but it sounds very much like it's missing on one of more cylinders. Probably a bad spark plug. Are you getting a CEL?

In my case i have no CEL, but the same experience otherwise. Rough idle at cold start. Also been noticing an odd vibration at very low speeds, like 5 mph/8km. It takes about 2 mins before the roughness stops at startup. Any thoughts appreciated.

[admranger]

Try running some fuel injector cleaner through it. That helped my idle issue when I got my car.

[aerof16]

Originally Posted by Weeee!

In my case i have no CEL, but the same experience otherwise. Rough idle at cold start. Also been noticing an odd vibration at very low speeds, like 5 mph/8km. It takes about 2 mins before the roughness stops at startup. Any thoughts appreciated.

How many miles and have you done the spark plugs yet? The engine uses a little more fuel during warmup, so it’s possible that your plugs are fouled and causing misfires or an incomplete burn during that time. Just a random guess though, if the car runs great otherwise it’s hard to say. You could pull a plug and take a look at it to see what’s going on.

If you do try fuel injector cleaner I’ve been hearing great things about this company and their line of products. My car runs great but I’m close to 85k miles, so I may run some of their products at my next oil change.


https://www.hotshotsecret.com/gasoline-extreme-12-oz/

[ma2600]

Do you know what they ended up doing? I have the same problem with my 18 530i

[New5Series]

Originally Posted by ma2600

Do you know what they ended up doing? I have the same problem with my 18 530i

I’m facing the same rough idle in my ‘21 530i.

Is this something that is only happening with 530’s? Has anyone with other models (540, 550) encounter the rough idle when the temperature starts dropping?

[ehrick]

Originally Posted by New5Series

I’m facing the same rough idle in my ‘21 530i.

Is this something that is only happening with 530’s? Has anyone with other models (540, 550) encounter the rough idle when the temperature starts dropping?

Hello, I’m experiencing a similar issue with my 2018 520i. The rough idle is most noticeable when the engine is cold, but it also occurs intermittently when the engine is fully warmed up. The idle feels as if the car is on the verge of stalling, with the RPM occasionally dipping as low as around 500 RPM. When the engine is warm, the frequency of the rough idle seems to reduce significantly, though it’s still noticeable at times. Otherwise, the car drives perfectly wonderful!

So far, I’ve replaced or cleaned the following components:

• Air filter
• MAF sensors
• Spark plugs and ignition coil packs
• MAP sensor; Throttle body (cleaned)

I’ve also used a fuel injector cleaner, but the rough idle persists. There are no CEL or fault codes when scanned. Any additional suggestions or insights would be greatly appreciated!