Jump to content
Sign in to follow this  
carrman

Preconditioning may have cracked the windscreen

Recommended Posts

I’ve always been careful with my cars and NEVER poured warm water on a frozen windscreen.

 

But I’ve really appreciated preconditioning my 530e to a nice temperature over the last week or so...until this morning.

 

The windscreen has cracked!!

 

OK it could be a manufacturing fault, but I’m sure it was the warm air on the cold screen.

 

Be aware!

 

I have contacted Autoglass for a new screen, and it’s likely to be a week or more before it’s convenient for me to have it fitted.

Edited by carrman

Share this post


Link to post
Share on other sites

No chance whatsoever that the air did that. If you poured boiling water on it, maybe.

 

the air will not be hot or insists enough to cause such a huge hike in instant glass temperature.

 

didnyoubhave a smalił crack/chip? If that froze over with moisture, it could have cracked during freezing (same principal as roads,rocks etc etc)

Share this post


Link to post
Share on other sites

My small crack has increased this week, centre of screen. Then got another in bottom right, piece if ice jammed in-between bonnet, screen and wiper arm.

 

Unlikely to be the preconditioning.

Share this post


Link to post
Share on other sites

I've had my pre-conditioning on all the time, including the cold spell, and didn't have any problems.

With all my previous cars I would pour warm water on the screen and that never caused any damage.

As others have said, there must have been a chip there already.

 

Share this post


Link to post
Share on other sites

Don't think you can rule out it out entirely, my f10 screen cracked while warming it up with air from the car while in sub zero temps. 

Still likely to be a chip as the fault point but the warming up action can then trigger it to crack. 

Edited by SuperDave

Share this post


Link to post
Share on other sites
10 hours ago, Monkeyfinger said:

If you use max defrost in any car, your going to get far more intense and direct heat on the screen than Pre-conditioning. The blower runs gently and the temperature is fairly gentle in my use of pre conditioning. 

Agree. I cannot see how pre conditioning would be different from classic warming up

Share this post


Link to post
Share on other sites
On 17/12/2017 at 9:25 AM, Monkeyfinger said:

If you use max defrost in any car, your going to get far more intense and direct heat on the screen than Pre-conditioning. The blower runs gently and the temperature is fairly gentle in my use of pre conditioning. 

 

Yes, agree.

I have a KW usage readout on the charging station and I see it start to draw current about 20 minutes before the programmed departure time.

The current draw seems to start slowly to begin with before ramping up, so I can't see it deliver such instant hot air that would break the glass, unless it was chipped in the first place.

Share this post


Link to post
Share on other sites

OK here’s an update from Autoglass ( who have sourced a genuine BMW screen for me tomorrow).

 

There was a VERY small chip actually under the wipers - this is where it started. 

 

Seems it was just back luck given where the chip was but heating  the screen probably triggered the crack.

Share this post


Link to post
Share on other sites
2 hours ago, carrman said:

OK here’s an update from Autoglass ( who have sourced a genuine BMW screen for me tomorrow).

 

There was a VERY small chip actually under the wipers - this is where it started. 

 

Seems it was just back luck given where the chip was but heating  the screen probably triggered the crack.

 

Likely to be freeze/thaw effect in that chip eventually making it bigger and bigger until it cracked. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×