I ones lost my tilt and slide sunroof of the cossie when doing about 130 mph. It was closed at the time and with a big bang it suddenly dissapeared at the motorway.. Luckally there was no one behind me so no damage to other cars. Does any one else has had this same experience??

 

God the number of times I have heard this happen over the last few years. Smit I can name off the top of my head now, but there was at least two other people who has had that happen to em.

 

So you say its a common problem than . But what causes it and can you prevent this happening (with high speed running of course..)

Since the day it happened to me I have never passed the 120 MPH again in the cossie....

 

Just old cars! It is quite a common problem, there is a lot of reduced air pressure over the top of a car traveling at those speeds and an old sunroof will just break.

 

Bloomin heck - scary or what???? Will new fixings help maybe??

 

I think it's something to do with the vents somewhere being blocked but i'm not 100% sure

 

there is too much pressure building up inside the car and there is not enough pressure outside
somethings got to give

if it's any consolation, i rememebr vauxhall had the same problem with some of their corsas, but they would be standing still and you only had to close the boot a bit too hard and the glass went "ping"

 

yeah heard that happen to my mate Pauls 3 door cosworth but they caught it just before it went they told me? have heard of it before

 

ive heard this before where the sunroof would just crack at high speed's

 

Like when the first VW Beetles were sold, they were so air tight you sometimes had a job to shut the door without a window open!

 

I have lost one before as well

Was about 220 miles from home and in February, so very cold.

Mine hit another car as well.

Steve.

 

Now that's bad... Hopefully nobody got hurt?


So I see more people know of this existing problem now maybe there someone who know a good and solid modification.

I was thinking of making some kind of metal brace between the handle and the screw in the middle of the sunroof.

 

Nobody hurt, didn't know it had even hit another car until i had a letter from the police

Steve.

 

my mate in his saph was racing a MR2 and hit about 140 and the sunroof came straight out with all the fixxings and runners!!!!! i have heard it is quite common, makes me wanna buy a motorsport shell hahahahah i wish!

 

must be due to a pressure difference under the glass to over it.

probably too much pressure inside the car - possibly due to blocked exit holes (rubber flaps behind the rear bumper) - as any low pressure on the roof area would be the same for all cars at that speed

 

It's all about aerodynamics. There is an upwards force on the roof of all cars.

This was very noticable on old cabriolets when they had the hood up - a large bulge seen above the front seats.

Obviously at greater speeds the greater the force and a sunroof is a weak point in the roof hence the reason for it giving way from time to time especially on older cars which may have corroded runners/fasteners.

Best solution is to remove the sunroof and weld the hole up!


Cheers,
Pete.

 

FFS why can't people just design cars properly!!!

Anyway, how often does anyone ACTUALLY use their sunroof? I think I've opened mine perhaps twice in the 4 years I've had the car, and then just to see if it worked.

 

Get an electric one and it'll be a breeze to open

 

Are these connected to the sunroof then!? Must make sure mine are clear...

 

I think it must be just rusted/weakened lug mountings on the underside of the sunroof, mine tried to pop out till I set it a bit lower, only by a few mm, don't know if it is the old screws snapping, but I replaced my roof with a better s/h one and SS screws, with CAP HEADS, so they don't sieze AGAIN I also used Coppaslip.
Works for me reguarly do over 150 no problems.
tabetha

 

yes - they are part of the whole cabin ventilation / pressurisation system

if you did not have them, or they are blocked, the air forced into the cabin by the blower and the forward motion creating a high pressure area at the base of the windscreen will just build up in the cabin creating a high pressure. if the pressure on the outside of the sunroof is low at high speed, the pressure difference will act on the area of the sunroof with an upward force, possibly strong enough to push it out

 

had the same prob..turns out the rear drainage pipes for the sunroof
were blocked..
i think air pressure from the front pipes caused the sunroof to pop..
cleaned them and had no prob's yet