Hi !
Just bought my 2006 E87 120i, it's a second hand with 56.000km, automatic, bought it with oil leaks and some other problems, wasn't afraid because I planed to fix them. But I noticed a weird rattle when the engine was cold especially when putting the car in R or D while the brake is still depressed, once the rolled a bit or the engine is warm the rattle disappeared I replace alternator's pulley and I fixed this rattle. (thanks to bimmerforums !)
I also replaced the vacuum pump (oil leak) and also the chain tensionner just in case of (I ordered the 2017 model to be sure to have the last revision). I changed the deflection pulley because the bearing was noisy.
The problem is when the car is hot she rattle and it sound like a diesel and I hate diesel... I also own a Mazda 3 with 3 times more kilometers, same horsepower and she is so quiet that when idling that sometimes it's almost impossible to say if the engine is running !
I read many, many, many topics about rattle with N42/N46/etc... petrol engine sounding like a diesel etc... but without real solution or help.
No power loss or nothing noticeable.
What I did :
-scan with Rheingold (no fault)
-vanos solenoid unplugged (no change)
-MAF unplugged (supposed to disable the valvetronic) : no change
-DISA unplugged: no change (rattle seems to come from exhaust side not intake)
I'm not sure but I think that the noise is more audible under the car, I crawled underneath but wasn't able to locate the rattle (too noisy).
I made a video :
https://www.youtube.com/watch?v=w-8jKzkF5-A
You can see the torque converter (automatic), I think it's somewhere around (maybe himself) don't know...
Here is an other video:
https://www.youtube.com/watch?v=bkziYMwhnA4
forget the tik tik sound, please focus on the rattle. Please note I made this video before replacing the deflection pulley (noisy bearing, you can ear it)
The rattle came slowly with the engine warming up but it's also noticeable when cold but other noises cover it. Once the engine is warm the rattle is the most audible noise. The exhaust is stock (muffler, etc.) but I find it a bit loud (don't know if it's supposed to be) so I'm starting to suppose I have a crack somewhere, this morning I tried to block exhaust and surprise I wasn't able to stall the engine (didn't even drop rpm), I wasn't able to totally block the exhaust because of the pressure build-up. So I plan to make an other test with a vacuum cleaner and engine off to see if I have a leak.
What do you mean ? Can an exhaust leak make my petrol sound like a diesel ? Does someone know where the rattle come from ? Any idea ?
Bookmarks