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N51 pinging/rattle sound under load/idling
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12-15-2018, 06:11 PM | #1 |
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N51 pinging/rattle sound under load/idling
Hello everyone, I've been chasing a rattle that is tied to engine rpm that starts around 1500-2000 rpms and goes up to about 4000-5000 rpms that I can only hear in the cabin while driving down the road or idling in park. Both situations my windows are up, no music on nothing like that or else the noise will be drowned out. If I let off the throttle the sound disappears and won't happen in those rpm ranges unless I'm pressing the gas. I replaced Vanos solenoids and the belt tensioner/idler pulley/serpentine belt to no avail. Any suggestions will be greatly appreciated
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12-17-2018, 12:12 AM | #3 | |
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12-17-2018, 07:54 AM | #4 | ||
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Possibly could be a loose heat shield by the exhaust somewhere or an exhaust bracket rattling around, that's gonna be my first thing to check when I get under the car in a few days. Mine is also auto |
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12-17-2018, 07:58 AM | #5 | ||
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Other than the heat shield or exhaust rattles, I pulled the upper DISA valve and tested both of them using INPA and they both tested fine and the upper valve looked good so I'm at a loss at this one so far, if you find anything keep me in the loop! |
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12-17-2018, 08:24 AM | #6 |
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Maybe Some part of the gearbox ?
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12-17-2018, 08:38 AM | #7 |
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I don't know what engine you have but on this website there are Some possible causes for rattling of the engine/its components and video's on iT. Might be worth checking out
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12-18-2018, 05:01 PM | #8 | |
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Possibly yes, these past few days it hasn't been happening so that's the really confusing part I think maybe something in the exhaust expands when it gets hot/contracts when cold and something is rattling somewhere but it's a pain in the butt haha |
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12-20-2018, 02:53 AM | #9 |
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Same issue here, off throttle goes away, on throttle reappears.
Gonna see if i can take a look at it one of these days when i get a new vent line from FCP. Usually, if you put it in park, have someone rev a little bit, check under and around the car see where the noise is coming from. From what people say it could be a loose heat shield. Doesn't sound serious. Let us know your findings! |
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12-20-2018, 04:08 AM | #10 | |
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I'm hoping it's something simple as that, it's super erratic though like some drives it happens sometimes it doesn't so it's pretty confusing. I popped the hood once and was revving it in park and it sounded like it was forsure coming from the driver side wheel-well, almost like coming from the engine bay near the intake so maybe somethings loose near there I'm not sure, work schedule has been pretty crazy so haven't had time to get it jacked up yet unfortunately but I will definitely report back once I get it in the air when/if I find something! |
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12-20-2018, 10:26 AM | #11 | |
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Very possible that something is loose, steady rpm's while checking the engine bay should help you figure out where its coming from. Requires 2 people, buy a friend a beer after |
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12-20-2018, 12:22 PM | #12 | ||
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Seriously haha! I've heard something about an exhaust bracket somewhere that mounts to the transmission that's a common breaking point but I'm not sure if I'd need to take it to the dealer or if I could check that myself? Never really dove under the car like that except to open the drain plug |
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12-20-2018, 07:06 PM | #13 | |
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First step would be to verify if the noise is coming from above or below, you don't want to have to put the car up on ramps and then take off the splash shield cover underneath if you don't have to. Below are some instructions on how to remove the spalsh shield https://www.pelicanparts.com/BMW/tec...d_Removing.htm Then its just a matter of figuring out where its coming from |
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12-21-2018, 02:06 AM | #14 | ||
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Would it be possible that something in the water pump could be rattling like that? Would I hear it that audibly in the cabin if it was? I took it to firestone where a buddy of mine works and put it on the lift and removed the splash guards and hit around anywhere and didn't find anything rattling but we didn't really know where to look. We found that I had a very slight coolant leak coming from the top of the engine from what looked like a leaking hose but that was all. All the exhaust seemed fine, but I was thinking about maybe a intake valve sticking or something to that nature? Im not very knowledgeable about that part of the engine but I'm not sure if that would be more audible or throw a code of some sort but this has been bugging the hell outta me because it doesn't sound good whatsoever! |
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12-23-2018, 06:17 PM | #15 |
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Here's a link to a video of the sound if anyone can get a better idea of what it could be. Sounds very like metal on metal to me which makes me think it's an exhaust bracket or something in the exhaust hitting something, thank you guys!
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12-24-2018, 02:26 AM | #16 | |
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engine/trans hollow whine
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