need help. noise after going over a big speed bump
08-04-2013, 04:53 PM
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need help. noise after going over a big speed bump
My son took the car a little too fast over a big speed bump with 5 adults in the car. There was a scrape after the front wheel cleared the bump and now there is a tapping sound that seems to be with the speed of the car even at very LOW speeds. i.e. 1-5 mph.
I'm guessing a heat shield is pushing against the drive shaft. But, I don't have any way to get under the car to see. Before I tow the car to the dealership, does anyone have any ideas what might have happened and what I should do?
Thanks for any advice.
I'm guessing a heat shield is pushing against the drive shaft. But, I don't have any way to get under the car to see. Before I tow the car to the dealership, does anyone have any ideas what might have happened and what I should do?
Thanks for any advice.
08-04-2013, 04:58 PM
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Just to clarify, this was in a parking lot and speed was very low but due to the height of the speed bump, we definitely hit the underside of the car as we went over the bump. The only thing I can see is the exhaust so I'm guessing the exhaust was pushed up and whatever is above it is touching the drive shaft. But, I can't see underneath the car so if anyone knows...
08-04-2013, 10:18 PM
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2018 GLC300 4Matic; 2005 C55; 2003 360 Modena
The exhausts are sufficiently clear from the driveshaft until the middle of the car (approx.), then the pipes come together. The rear trans mount is pretty high up from both exhausts coming down from the headers, and not just behind the front wheels.
If you're sure that you hit just after the front wheels, the lowest parts that I see are the exhausts. If you hit those hard enough, I would suspect that the damage is a broken exhaust at a connection, and hopefully not a cracked header or cat.
Leave the car in park and rev the engine, if the tapping noise is still there, I'm guessing a cracked exhaust part or connection that is now a leak.
I don't see where damage just after the front wheels would be near enough to the driveshaft to cause a rubbing noise.
If you're sure that you hit just after the front wheels, the lowest parts that I see are the exhausts. If you hit those hard enough, I would suspect that the damage is a broken exhaust at a connection, and hopefully not a cracked header or cat.
Leave the car in park and rev the engine, if the tapping noise is still there, I'm guessing a cracked exhaust part or connection that is now a leak.
I don't see where damage just after the front wheels would be near enough to the driveshaft to cause a rubbing noise.
08-08-2013, 11:35 AM
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Unfortunately, it is not the exhaust. I will get it towed sometime in the next week or two to get it looked at and report back.
The exhausts are sufficiently clear from the driveshaft until the middle of the car (approx.), then the pipes come together. The rear trans mount is pretty high up from both exhausts coming down from the headers, and not just behind the front wheels.
If you're sure that you hit just after the front wheels, the lowest parts that I see are the exhausts. If you hit those hard enough, I would suspect that the damage is a broken exhaust at a connection, and hopefully not a cracked header or cat.
Leave the car in park and rev the engine, if the tapping noise is still there, I'm guessing a cracked exhaust part or connection that is now a leak.
I don't see where damage just after the front wheels would be near enough to the driveshaft to cause a rubbing noise.
If you're sure that you hit just after the front wheels, the lowest parts that I see are the exhausts. If you hit those hard enough, I would suspect that the damage is a broken exhaust at a connection, and hopefully not a cracked header or cat.
Leave the car in park and rev the engine, if the tapping noise is still there, I'm guessing a cracked exhaust part or connection that is now a leak.
I don't see where damage just after the front wheels would be near enough to the driveshaft to cause a rubbing noise.
08-11-2013, 02:24 PM
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This happened to me a couple of years ago. You can just jack the car up, secure with jack stands, wear protective goggles, slide under the car with a flash light, long flat head screwdriver and some wire snips. In my case I found that the heat shield had been torn and pulled close to the drive shaft in and about the middle of the car. I pried the heat shield up and out of the way of the drive shaft with the screw driver and, if I remember correctly, snipped off a small piece of the heat shield that was all torn up. Whole operation took less than 15 minutes. Problem solved, never to return. This is actually faster and cheaper than taking the car to the dealer. A friendly mechanic with a lift can do this in 5 minutes.
10-08-2013, 12:15 PM
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Tump43, you are right. I finally got under the car with 2 jacks and pulled the heat shield from around the middle of the car. I don't know how it got pushed up there since there isn't anything obvious that could have caused it other than the exhaust system moving as a whole and pushing on the heat shield. But, it was easy to pull back with my hand and everything is good now.
Sorry: I should have reported back earlier on resolving this issue. I'm back on mbworld.org because my electrical system took a nose dive this morning...
Sorry: I should have reported back earlier on resolving this issue. I'm back on mbworld.org because my electrical system took a nose dive this morning...
Last edited by jywang; 10-08-2013 at 12:18 PM.
