Today while I was driving in stop and go traffic I had something downright awful happen.

I could smell a very slight burning smell at the end of my trip, but didn't think much of it. When I was about two blocks from my destination I noticed something about the 540, I couldn't place what, didn’t feel right. By the time I was half a block away I knew something was very wrong. As I slowed down and hit low RPMs and low speed, I could hear this horrible RPM dependant noise coming from the engine bay. I put the transmission into neutral trying to make sure I was not out of fluid... still the noise... it seemed to be getting louder. No check engine light, temp gauge is fine, nothing out of the ordinary... just a sound/clunk that almost sounded like pre-detonation but could be slightly felt in the car. By the time I was parking I was desperate to turn the car off because it had begun to sound so absolutely awful. I though my engine was tearing myself apart. Distraught I opened the hood to find not a single visible problem. The engine seemed hot, but I had been up to 5000 rpms+ on the drive over, so it wasn't getting a break in the Florida heat, but nothing a BMW can't handle.

Anyways, the temp gauge showed nothing out of the ordinary, although it sounded as if coolant was beginning to boil, which really worried me. I left my hood open for about 45 minutes and kept thinking about the problem. The sound was definitely coming from the front/lower driver's side. I looked at the alternator, but it seemed to at least look all right. I don't know where the power steering pump is, but I had been getting a whine while turning right and getting the RPMs up a bit, so I suspected maybe it was dying or seizing up, but I didn’t know yet. When I had help there, I had a friend start the car while I listened. Initially the noise was not as bad, but after the engine was on for about 5 seconds, the noise got a lot worse fast. We turned the car off. It sat again, and curiosity got the best of me, so I got down for a real good look and had another go at cranking it. The noise upon cranking it was so unimaginably unbearable that I had to cut it before it even started. It sounded like the starter motor was blending a can full of metal nuts, it was the most awful noise... I hope I never hear it again.

So, I left the car for two hours and went on with what I had originally needed to do. When I came back, I tried one last time to see if a two hour break helped. It did, for about 10 seconds. Then the noise reappeared and got progressively worse again. (I checked all fluids/levels... nothing in oil, no low fluids etc) So I called BMW roadside to have it towed.

Flash forward another three hours. I strongly told the tow truck guy NOT to start the car, but he did anyways. It didn't make any noise for him, at all. Go figure. After having it run for about 30 seconds the noise quietly reappeared.

Here is the catch.... when the noise peaks, dust begins to "blow" or so it seems up out of the engine bay in the front left. A (smart) friend suggested perhaps as I thought a pulley had seized or something and that the belt was trying to slip over it, but making one hell of a racket. I don’t know the locations of what components are down there though that would make such a hellacious noise. I am afraid I will get a huge bill for these repairs after I just had my motor in for $4000 of work to fix leaky valve covers, and otherwise check everything over, fix what needed fixing. Now, some two months later my 540 is out of commission again.

I am not a happy camper! I though this car would be more reliable!

Anyways, I am hopeful that the bottom end of my motor didn't just tear itself to peices, but can anyone offer some insight into what may have happened? Nothing to indicate this would happen... no problems driving on the way over... nothing in the weeks before. The car was completely normal and the problem came on all too suddenly.

A diagram of what is located/tucked under the driver’s side of the motor would be immensely helpful. If you have gotten this far, I applaud you! Thanks for reading about my problem.

-----Nate