Loud knocking noise

[Trizz]

Hey everyone this is my first thread and I was hoping that someone could help me out

I was off to work when my 95 BMW started to make this loud knocking noice as if I was driving a heavy duty truck. The noise will fluctuate if I adjust the AC but it will not accelerate very much. Please help me out

[NC540]

Post a video

[BigC986]

Knocking usually means one of the rods are bad. Youre motor is basically toast. May want to look into a replacement.

[TonyAngel]

Your description is very vague. Knocking noises can be caused by a lot of different things. Loud is also very subjective. Still, when someone runs the words "loud knocking noise" together in succession, the first thought that pops into my head is that there's a spun connecting rod bearing. Based on the vagueness of your description, I'm gonna guess that you have no idea so I'd suggest that you take it to someone that does. Does/did your car have the proper amount of good clean oil in it?

I sure hope for your sake that it isn't a rod knock. If it is, that's a pretty big deal.

For what it's worth, welcome.

[MauiM3Mania]

Moved from General BMW sub-forum.

[shogun]

First of all we have to know from where the noise comes, engine bay, wheels, driveshaft = from under front seats, etc.

[JDStrickland]

Hey everyone this is my first thread and I was hoping that someone could help me out

I was off to work when my 95 BMW started to make this loud knocking noice as if I was driving a heavy duty truck. The noise will fluctuate if I adjust the AC but it will not accelerate very much. Please help me out

Another, "my car is broken, what's wrong?" kind of threads.

Adjust the AC. What does that mean, turn it on or off? It will not accelerate very much, what does that mean in the context of the AC? Given the description of the symptom set, your best action is to put the car on a flat bed and take it to the shop.