BimmerFest BMW Forum banner
1 - 20 of 23 Posts

· Goes with the Flow
Joined
·
76 Posts
Discussion Starter · #1 ·
I was driving my 328xi 08 earlier today towards a new area and I wasn't familier . I was driving about 45 mph and then out of no where I notice a huge gap on the ground , I had a car right behind me and I didn't want to suddenly brake and get hit and I couldn't avoid it because I had a car in my right hand side and incoming traffic on my left. So I hope for the best slowing down as quickly as possible so my speed dropped around 25mph driving over it , wishing the my car was wide enough not to bounce , :cry: the car bounce up and down and then I heard a loud noise , almost like a metal bang underneath the back seats/trunk . I didn't hear anything else like the front bumper or back bumpers hit the ground , it was just that metal bang . I pulled over and looked underneath the car and it seem fine with no leaks and no bents from what I can tell . But I'm still a bit worry if there is going to be anything long term, or did the alignment get messed up ? Has his happen to anyone and if so , what has been your consequence ?
 

· Flying monkey herder
Joined
·
8,298 Posts
check your tires for bulges.
 

· Registered
Joined
·
119 Posts
This is what happened to mine just over a week ago.


Of course, I felt a bad vibration immediately. Got it to a local tire shop and then found out I had a total of three bent rims. Had them straightned and now I think they are ok. However, the tire shop told me that the inner layer of the tire (which is pictured) is split and he didn't think it would hold up long. He may have been trying to sell me a set of tires but I wasn't ready to buy. A person needs time to research a tire purchase!

Anyway, as Orient330iNYC points out, you might have tire damage that might not be apparent right now. Keep a feel out for new vibrations, especially at higher speeds, and check your tread thoroughly for any irregularities due to alignment and/or broken internal belts which will cause bulges.
 

· Flying monkey herder
Joined
·
8,298 Posts
Thanks, I didn't even consider the tires .
when you have a hard (sounds like you bottomed the suspension) sharp edge hit, the tire gets pinched between the edge of the hole and the rim. if its a hard enough hit, you'll tear the cords in the sidewall of the tire. the tire might not go flat right away, but a bulge will form at the site of the tear. it may take a few days or so to form, and can be on the inner sidewall or outer sidewall.

bad news is, there is no way to repair a sidewall rupture like that. the tire needs to be replaced as the sidewall's supporting structure has failed and is only being held together by a superficial layer of rubber.
 

· Goes with the Flow
Joined
·
76 Posts
Discussion Starter · #6 ·
This is what happened to mine just over a week ago.


Of course, I felt a bad vibration immediately. Got it to a local tire shop and then found out I had a total of three bent rims. Had them straightned and now I think they are ok. However, the tire shop told me that the inner layer of the tire (which is pictured) is split and he didn't think it would hold up long. He may have been trying to sell me a set of tires but I wasn't ready to buy. A person needs time to research a tire purchase!

Anyway, as Orient330iNYC points out, you might have tire damage that might not be apparent right now. Keep a feel out for new vibrations, especially at higher speeds, and check your tread thoroughly for any irregularities due to alignment and/or broken internal belts which will cause bulges.
ouch , I'll check the rims to see if there was any damage . I wouldn't expect the tires and rims to get damage from pot holes, I'm glad I posted my concern. I'll look at them throughout and hope for the best. Now for the tire damage that might not be visible now , how long of a period would it take for the damage tires to appear or feel unnormal ? Also, did you & Orient330iNYC received any damage on the body frame or anything else under the car ?
 

· Goes with the Flow
Joined
·
76 Posts
Discussion Starter · #7 ·
when you have a hard (sounds like you bottomed the suspension) sharp edge hit, the tire gets pinched between the edge of the hole and the rim. if its a hard enough hit, you'll tear the cords in the sidewall of the tire. the tire might not go flat right away, but a bulge will form at the site of the tear. it may take a few days or so to form, and can be on the inner sidewall or outer sidewall.

bad news is, there is no way to repair a sidewall rupture like that. the tire needs to be replaced as the sidewall's supporting structure has failed and is only being held together by a superficial layer of rubber.
So that metal sound wasn't the actual frame hitting the ground , it was the sound of the bottoming suspension ?
 

· Flying monkey herder
Joined
·
8,298 Posts
So that metal sound wasn't the actual frame hitting the ground , it was the sound of the bottoming suspension ?
without having heard it, i couldnt say. but more than likely it was the suspension bottoming out. it would sound like a loud "BANG" vs a grinding crunching scrape.

if you actually hit bodywork, you would see the abrasions and gouges
 

· Flying monkey herder
Joined
·
8,298 Posts
ouch , I'll check the rims to see if there was any damage . I wouldn't expect the tires and rims to get damage from pot holes, I'm glad I posted my concern. I'll look at them throughout and hope for the best. Now for the tire damage that might not be visible now , how long of a period would it take for the damage tires to appear or feel unnormal ? Also, did you & Orient330iNYC received any damage on the body frame or anything else under the car ?
tire and rim damage is very very common unfortunately, the larger the rims, the more prone to damage. 16s are fairly immune.
 

· Goes with the Flow
Joined
·
76 Posts
Discussion Starter · #11 ·
without having heard it, i couldnt say. but more than likely it was the suspension bottoming out. it would sound like a loud "BANG" vs a grinding crunching scrape.

if you actually hit bodywork, you would see the abrasions and gouges
The sound was a big bang , I didn't hear any grinding it was just 1 loud bang . And the rims are standerd which I'm guessing those are 16 which would work in my favor as you mention their immune .
 

· Goes with the Flow
Joined
·
76 Posts
Discussion Starter · #12 ·
without having heard it, i couldnt say. but more than likely it was the suspension bottoming out. it would sound like a loud "BANG" vs a grinding crunching scrape.

if you actually hit bodywork, you would see the abrasions and gouges
ahh thanks for the eye opener , I now have an idea what to look out for in the next couple of days .
 

· Flying monkey herder
Joined
·
8,298 Posts
. It would take multiple large pot holes to do any such damages to 16's?
not necessarily, 16" rims are less prone to damage but not immune to it. more sidewall= less likely to pinch. but a hard enough hit can damage any tire.

i'm not sure if stock wheels on the coupe are 16s
 

· Banned
Joined
·
10,511 Posts
So I hope for the best slowing down as quickly as possible so my speed dropped around 25mph driving over it , wishing the my car was wide enough not to bounce , :cry: the car bounce up and down and then I heard a loud noise , almost like a metal bang underneath the back seats/trunk . I didn't hear anything else like the front bumper or back bumpers hit the ground , it was just that metal bang.
BmwLifestyle, what you heard was the infamous "Pothole Explosion."

Appears to be the result of BMW strut design + springs + ever larger rims + lower profile run flat tires; the problem is endemic 2006 - 2010. Yup, mostly fixed in 2011.

As CaptainAudio has noted, replacing your shocks with Koni FSD's largely eliminates the problem, run flat tires or no. Non-RFT's smooth your ride very noticeably in addition.

Recommend you SEARCH for "Pothole Explosion" etc. for perspective - you'll have many hits this forum alone! Bing & Google deliver more technical info, but you'll wade through more hits than thought possible....

re: tech issues, I'll save you some time: Pay attention to the shock resistance curve, stock vs. FSD's, the secret to success. A major player, also check spring curves, linear vs. progressive [stock] springs.

Emoticon Smiley Yellow Icon Smile
 

· Goes with the Flow
Joined
·
76 Posts
Discussion Starter · #15 ·
BmwLifestyle, what you heard was the infamous "Pothole Explosion."

Appears to be the result of BMW strut design + springs + ever larger rims + lower profile run flat tires; the problem is endemic 2006 - 2010. Yup, mostly fixed in 2011.

As CaptainAudio has noted, replacing your shocks with Koni FSD's largely eliminates the problem, run flat tires or no. Non-RFT's smooth your ride very noticeably in addition.

Recommend you SEARCH for "Pothole Explosion" etc. for perspective - you'll have many hits this forum alone! Bing & Google deliver more technical info, but you'll wade through more hits than thought possible....

re: tech issues, I'll save you some time: Pay attention to the shock resistance curve, stock vs. FSD's, the secret to success. A major player, also check spring curves, linear vs. progressive [stock] springs.

View attachment 341022
I had no idea it had it's own name, this issue is more common then I thought. Thanks for the recommendations , once I read your post I too my car out for a spin to pay close attention to anything in different. I didn't notice anything yet. I will be looking into replacing my shocks, N.Y streets are horrible .
 

· Banned
Joined
·
10,511 Posts
I had no idea it had it's own name, this issue is more common then I thought. Thanks for the recommendations , once I read your post I too my car out for a spin to pay close attention to anything in different. I didn't notice anything yet. I will be looking into replacing my shocks, N.Y streets are horrible .
Def post to, or PM, CaptainAudio. He will fill you in, also being a NYC kind o'guy....
 
1 - 20 of 23 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top