Yesterday afternoon I went to start my car and heard a knocking sound. At first I thought it was an exhaust leak or exhaust rattle so I checked under the car but it sounded like it was coming from the engine bay/header area. Popped the hood and clearly heard a knock sound, took my phone out really quick to reference with video back and turned the car off. Car was running for about 3 minutes. Last time I drove the car was Wednesday, 2 days prior and I did not hear anything related to anything you hear in the video. I immediately sent the video to a few local shops here in San Diego and called Malek at MRF. Everyone told me to not drive he car and to have it towed to the shop. I decided to have it towed to MRF Engineering last night as I believe if anyone can tell me if this is savable it will be him. If anyone has any advice in this situation or had a similar problem and what their outcome is. The way I look at it from talking to Malek, either it can be saved and a simple bearing job is needed or the crank is damaged and at that point a rebuild or new engine is necessary.
History on the car: 2010 BMW M3 Coupe. 101,000 miles. 3rd owner, owned it since 65,000 miles. Car was purchased with a stack full or service and maintenance records. Very well maintained. I did oil changes with liqui moly 10w60 every 7,000 miles. I performed an oil change at 100,000 miles ago so just recently about 2 weeks ago.
Mods: stock x pipe with primary and secondary cat delete. Gintani e85 tune. Been running this tune for about 1-2 months, really hoping it's not related.
Update: Malek texted me this morning saying that based on his preliminary diagnosis, he believes I'm getting bottom end rod knock. He said it's not terrible yet, so it might be savable. It is ether rod knock or main bearing failure. He said he will be inspecting the oil next. I'll keep everyone updated.
Update #2: Malek pulled the oil pan and found that none of the bearings spun. They were severely damaged but nothing spun. He looked at the crank, pistons, cylinder walls and nothing was damaged. He looked at the main bearings and they looked fine. He said usually when main bearings start failing you will see a blue hue to them and he did not see that upon inspection. He said I am very lucky and to buy a lottery ticket lol he will be proceeding with a bearing change. I will post a picture of my bearings they look terrible lol.