Author Topic: hood flapping  (Read 8415 times)

blue230sl

  • Guest
hood flapping
« on: December 05, 2007, 16:03:28 »
the corners of my hood flap or bounce when i'm moving fast enough.
the rubber stops are in place.
any suggestions on what might be causing this?
any one else have the same experience? and solution??
btw, the hood is not original to the car. and is not as well fitted as it should be.

john
64 230sl
89 190e 2.6

Chad

  • Guest
Re: hood flapping
« Reply #1 on: December 05, 2007, 17:11:47 »
They do bounce a bit normally, a couple mm, but how much would you estimate the shake is on yours?  I suspect that fitting the hood better will help make things more normal if they are not presently?

1967 230SL

Douglas

  • Guest
Re: hood flapping
« Reply #2 on: December 05, 2007, 17:12:29 »
John,

How are your engine mounts? Also, how are the shocks?

For what it's worth, I noticed the hood/bonnet for the 280 SL in the trailer for "The Last King of Scotland" is doing this exact same thing, so you're not alone out there:

http://www.apple.com/trailers/fox_searchlight/thelastkingofscotland/




Douglas Kim
New York
USA

blue230sl

  • Guest
Re: hood flapping
« Reply #3 on: December 05, 2007, 18:38:40 »
Quote
Originally posted by Douglas

John,

How are your engine mounts? Also, how are the shocks?
 
they only bounce a few mm as chad mentioned, and engine mounts are good, shocks seem to be good too; the ride is good...guess i'll have to go faster to smooth out the bounce :D



john
64 230sl
89 190e 2.6

sjiatrou

  • Guest
Re: hood flapping
« Reply #4 on: December 05, 2007, 21:27:41 »
Have you checked the vertical alignment of the hood bumper stops?  I found the one on my passenger side was too low (about 1/8") and it was allowing the corner to vibrate with increased windspeed over the hood at highway speeds.  A quick raising of the bumper solved the problem. To check it, gently push down (with one finger) on the corner of the hood, there should be no play, if there is then the bumper stop is too low.



Steve
Seaside, CA
1964 230sl roadster
White (050)/Black (116)
« Last Edit: December 05, 2007, 21:31:30 by sjiatrou »

hauser

  • Guest
Re: hood flapping
« Reply #5 on: December 05, 2007, 21:48:17 »
I have seen the corners come up during hard turns.  Is this what you are experiencing?

1969 280sl 5 spd
Gainesville, Fl.

blue230sl

  • Guest
Re: hood flapping
« Reply #6 on: December 05, 2007, 22:09:51 »
quote:
Originally posted by hauser

I have seen the corners come up during hard turns.  Is this what you are experiencing?

1969 280sl 5 spd
Gainesville, Fl.



no, it's a rapid flapping of both corners at highway speeds

john
64 230sl
89 190e 2.6

hauser

  • Guest
Re: hood flapping
« Reply #7 on: December 05, 2007, 22:57:19 »
Do you have a metal bar across the lower half of the hood's underside?

1969 280sl 5 spd
Gainesville, Fl.

blue230sl

  • Guest
Re: hood flapping
« Reply #8 on: December 06, 2007, 07:01:56 »
quote:
Originally posted by hauser

Do you have a metal bar across the lower half of the hood's underside?

1969 280sl 5 spd
Gainesville, Fl.



yes bar is there

john
64 230sl
89 190e 2.6

waqas

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  • USA, TX, Austin
  • Posts: 1738
Re: hood flapping
« Reply #9 on: December 06, 2007, 10:27:50 »
quote:
Originally posted by sjiatrou

Have you checked the vertical alignment of the hood bumper stops?  I found the one on my passenger side was too low (about 1/8") and it was allowing the corner to vibrate with increased windspeed over the hood at highway speeds.  A quick raising of the bumper solved the problem. To check it, gently push down (with one finger) on the corner of the hood, there should be no play, if there is then the bumper stop is too low.



Steve is on to something here. By definition, if the hood latch is tight and correctly adjusted (is it?), then the hood stops are the most likely culprits.

These little bumpers have a threaded stem to make height adjustment, as well as a locking-nut to prevent movement. They also have a rubber tip where they meet the hood (a friend's car had one missing rubber tip and no paint left under that corner of the hood!).  Make sure yours are still there and in good shape (dirt-cheap to replace).

Waqas in Austin, Texas
Waqas (Wa-kaas) in Austin, Texas

blue230sl

  • Guest
Re: hood flapping
« Reply #10 on: December 06, 2007, 17:29:47 »
quote:
Originally posted by waqas

quote:
Originally posted by sjiatrou

Have you checked the vertical alignment of the hood bumper stops?  I found the one on my passenger side was too low (about 1/8") and it was allowing the corner to vibrate with increased windspeed over the hood at highway speeds.  A quick raising of the bumper solved the problem. To check it, gently push down (with one finger) on the corner of the hood, there should be no play, if there is then the bumper stop is too low.



Steve is on to something here. By definition, if the hood latch is tight and correctly adjusted (is it?), then the hood stops are the most likely culprits.

These little bumpers have a threaded stem to make height adjustment, as well as a locking-nut to prevent movement. They also have a rubber tip where they meet the hood (a friend's car had one missing rubber tip and no paint left under that corner of the hood!).  Make sure yours are still there and in good shape (dirt-cheap to replace).

Waqas in Austin, Texas




thanks guys - the left bumper stop WAS too low, now adjusted.
and the hood latch was not bolted down completely. that's taken care of too. road test tomorrow...

john
64 230sl
89 190e 2.6

blue230sl

  • Guest
Re: hood flapping
« Reply #11 on: December 07, 2007, 16:24:16 »
quote:
Originally posted by waqas

quote:
Originally posted by sjiatrou

Have you checked the vertical alignment of the hood bumper stops?  I found the one on my passenger side was too low (about 1/8") and it was allowing the corner to vibrate with increased windspeed over the hood at highway speeds.  A quick raising of the bumper solved the problem. To check it, gently push down (with one finger) on the corner of the hood, there should be no play, if there is then the bumper stop is too low.



Steve is on to something here. By definition, if the hood latch is tight and correctly adjusted (is it?), then the hood stops are the most likely culprits.

These little bumpers have a threaded stem to make height adjustment, as well as a locking-nut to prevent movement. They also have a rubber tip where they meet the hood (a friend's car had one missing rubber tip and no paint left under that corner of the hood!).  Make sure yours are still there and in good shape (dirt-cheap to replace).

Waqas in Austin, Texas



thanks again, with the bumpers raised and the latch properly bolted down, the flapping is gone... :)

john
64 230sl
89 190e 2.6

Chad

  • Guest
Re: hood flapping
« Reply #12 on: December 15, 2007, 21:29:41 »
Good job.  Glad to hear that fitting the hood solved the whole lotta shaking going on.

1967 230SL

hauser

  • Guest
Re: hood flapping
« Reply #13 on: December 15, 2007, 22:37:09 »
It is always the obvious that keeps some of us scratching our heads. ;)   One time I was installing a foglight set and just couldn't get it to work.  The wires were fine, there was power when the switch was turned on and yet no light.  It turns out the housing was metal and the wire tabs that held the bulb in place had to be bent backwards to touch the back of the housing.  Nothing more than a simple ground issue.  Be persistent and don't give up.

1969 280sl 5 spd
Gainesville, Fl.