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#1
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Vibration issue.
Anyway, I have been trying to track down a vibration issue from the engine and / or drivetrain for a while now. It’s kind of hard to explain but here goes.. When driving under light load there is a harshness/ drone / vibration at about 1700rpm. I can feel it through the footrest if I have my foot resting against the side. I can also feel it through the park brake handle. It does not do it all the time - one day it’s there the next it’s not as bad. It’s not major but it’s there and having had two identical X5’s at the same time I know it’s not right. It does not do it at the same rpm in P or N. I am due to replace the bigger guibo joint next week to se if that helps reduce it. The centre support bearing is ok. Next on the list is the front driveshaft guibo. I’m reluctant to keep throwing parts at it as that can get expensive. At idle in P you can barely tell the motor is running. If I put it in D or R then I can feel it. This led me to replace the engine mounts but the vibration was so bad I put the old ones back. This may have been due to cheaper eBay mounts and not bmw but I’m not sure. Are the transmission mounts known to give trouble? I’ve tried to take a look at mine but can’t see it as it’s hidden. I got a pry bar in there and there is movement but it didn’t seem bad to me. Another vibration which I’ve only just found in the last few months was when I accidentally stood on the gas pedal when in P and the engine hit the red line. There was a tremendous vibration at 4000rpm onwards. The only way I can describe that is if you have a disc spinning on a wooden dowel and it goes too fast and chatters if you know what I mean. The transmission has recently been rebuilt and the torque converter replaced so in theory that should be ok but it does feel like the rear of the engine area. Has anyone experienced this type of issue or can shed any light on it? I do apologise for the rather long explanation. If anyone has any questions about it please ask. |
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#2
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Hard to diag from a description but, if the motor mounts haven't been done, they are due. Probably twice by this time, though you don't give your mileage. The trans mount is actually a transfer case mount. Single large bushing. Probably shot at this point as well. Factory mounts are made by Corteco BTW, bought my engine mounts on Ebay for ~$100/pr I think. Guibos are also suspect, CSB on the rear prop shaft, so many possibilities as all these parts start to introduce NVH around the same time (~100k +/-)
Throwing parts at it is painful to the wallet, but I find it's best to do everything all at once so I only suffer once. But I do my own work so it helps limit the financial pain. Though my back feels the rest of that $$$ savings.
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2005 X5 4.4i Build 04/05 Maintenance/Build Log Nav, Pano, Sport (Purchased 06/14 w/ 109,000 miles) (Sold 8/15 w/121,000 miles) 2006 X5 4.8is Build 11/05 Maintenance/Build Log Nav, DSP, Pano, Running Boards, OEM Tow Hitch, Cold Weather Pckg (Purchased 08/15 w/ 90,500 miles) 2010 X5 35d Build 02/10 Nav, HiFi, 6 DVD, Sports Pckg, Cold Weather Pckg, HUD, CAS, Running Boards, Leather Dash, PDC, Pano (Purchased 03/17 w/ 136,120 miles) |
#3
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Sorry yes the mileage is 170k and the X5 is 20 yrs old - quite possibly on original rubbers.
I agree that the mounts probably do need replacing but like you say it can get expensive. The vibration at the 4000rpm is something different I reckon. |
#4
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Get an app similar to or exactly this one:
https://apps.apple.com/us/app/vibrat...o/id1089589547 measure the exact frequency of the vibration. Often a little math will help you find the source. (Eg: when the frequency is 3x the wheel rotation or 4.1x, it's likely a CV axle or CSB). (or GIUBO).
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2011 E70 • N55 (me) 2012 E70 • N63 (wife) |
#5
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I had a similar app called Shimmy finder or something like that. Couldn't figure it out.
There is one by Weber Auto that is supposed to be really good but I'm not sure I want to shell out £85 for an app although it could cost more in the long run anyway.. |
#6
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Ok so I’ve just used that Vibration Isolator app. Three scans- going from right to left in this order- one in idle in P,one driving circa 1500rpm to 2000rpm and one at idle in D.
It’s a photo of my phone photos by my iPad so the red dots are missing from the high peaks. If anyone can figure that out I’ll be amazed. |
#7
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Vibration issue.
So the driving one shows the cars overall resonance. (i was measuring my car blown in a wind storm the other day. Just about 3 Hz).
So the frequencies you are seeing aren't related to drive train because you aren't moving. That will make it easier to find the source. You need to re-do the test with the hood open and put the phone right on the motor. Look for the spikes you see at idle in P and D (use a helper unless you have more faith than me in a parking brake) (I suppose a curb will do a fine job of holding back a car at idle just have a backup plan like a wall/tree past the curb in case a cat jumps in your car and his the gas. You want to see if the spikes match but get taller on the motor that will lead you to consider the motor is the direct source and the mounts are for sure the problem. The less common yet not surprising option is the CV axles particularly the fronts. When the CV joints wear and they get the equivalent of gear backlash, and especially when at idle in drive; The drive train will tension and release each power stroke (or some harmonic). Idle of estimate 700 rpm means 700/4=175 power strokes per minute 175/4=43.75 hmmm. So unsurprising there is a direct tie to the engine pulse, but why is it shaking the car; since you already tried the engine mounts, it's likely CV axle or the GIUBO. I've seen this be the CV axles at least half a dozen times on xo and personally with wife's e53 3.0. (so bad I had to put car in neutral at red lights). Bumping up the idle speed will help a lot before changing parts. I usually set my idle about 50 higher than EPA rules force the company to use.
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2011 E70 • N55 (me) 2012 E70 • N63 (wife) Last edited by andrewwynn; 04-21-2022 at 03:01 AM. |
#8
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I would maybe try an experiment: what happens to the shake with all the wheels off the ground. Especially with car in drive, when you let foot off the brakes and let the wheels start to turn: if the shake vaporizes, very good chance it's drivetrain.
The other experiment; get on a long slight hill just enough to have engine load and reproduce the vibration. CVs have 6 and 3 lobes and GIUBO turns 3.91x the speed of your wheels. 7.3 ft per revolution do some math. If you get a shake 3x the wheel rev it's the inner CV joint. 6x it's the outer, 3.91 it's the GIUBO (JOO-boh). Do some s curves under load, getting the CV into less worn and more worn grooves will help determine if CV is the problem. Oh: coincidentally, a buddy of mine just asked me today how to sell a brand new right front CV axle.
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2011 E70 • N55 (me) 2012 E70 • N63 (wife) |
#9
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Interesting that you mentioned CV axles as my front left (from drivers perspective) sometimes clicks on full lock so have thought about swapping new ones in. Again though, it's throwing parts at it until it's cured.
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#10
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You may be able to vibration test the CV itself though the left one much harder to get to, or possible to get a big vice grip on and bind the inisde to confirm that's the trouble.
Clicking does almost always mean it's shot. Also there is only a left/port and right/starboard. The side of a car doesn't change when you are inside or outside. Does your right arm turn to a left arm when somebody stands in front of you? I just thought of a possible quicker way to test: park on a hill such that the car will hold itself still in drive. Hypothesis: the preload on the drivetrain won't allow the backlash that is currently allowing the amount of drivetrain "hammer" that is causing the shake. You can maybe preload just one corner at a time by driving into a brick to help establish a corner. You can also do the vibration analysis right on a wheel itself.
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2011 E70 • N55 (me) 2012 E70 • N63 (wife) |
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