October 20, 2023,
What's being done: Belt Tensioner Replacement
Well... already had an issue with my m3. However! A very small one and an easy fix. After owning the car for a few months, I started to notice a rattling noise becoming more transparent when the car was at idle. I am always hyper sensitive to noises going on with my cars, which is both a blessing and a curse. Good because I can address issues as soon as it happens, but also bad because I am constantly listening for a new noises that pop up.
In this case, the noises started to become more and more noticeable as time went on. Instead of panicking, I did some diagnostics on the car to see if I could pinpoint the issue. Turned the car on and opened the hood waiting for the noise to click on. Sure enough, it was audible pretty quickly and I tracked down the noise. I knew it was coming from the front of the car, so looked down through all the lines and hoses and noticed the belt tensioner was rattling pretty violently. At first I told myself, maybe it's supposed to be move that much, but deep down I knew it was not normal. Did a bit more digging and research on the forums and it seems like these belt tensioner are something that does fail over time. Granted the car was under 20k miles, it was in need of replacement.
Picked up an OEM replacement from FCP Euro and it arrived at my door in a day or two. Little nerve-racking since this was my first "real" fix of the car since I took ownership, but I hopped into the garage and got to work. Now, the actual replacement is fairly simple. Remove the tension, unbolt, bolt new one on, and put the tensioner back. However, we all know zee Germans like making use of every square inch of their engine bays. Because of this, I had to remove quite a few things to get to the part. And even so, there was hardly any room to work.
After about an hour or so of squeezing my hands down there, I managed it get it into place, bolted up, and everything back in its spot. Started the car up and thankfully, the noise was gone! Always such a great feeling diagnosing an issue/noise and fixing it yourself. Huge sense of accomplishment and pride!
I was able to document the entire install so if anyone is interested in a step by step and see how it's done, check out the video below.