When the clunk happens, it's usually when the airbrake self-tests. It's been a common issue for all the McLarens, all the way back to the 12C. Calibration with an MDS can fix it, at least temporarily.

I don't think I've ever heard the clunk during normal operation. Your car's under warranty; maybe visit your dealer.

 

It is normal. All 3 of my mclarens have done it. The 750 performs a self test every time the air brake is activated. Nothing to worry about.

 

I did see some posts about clunking during the initial “self-test”, but should it clunk every time the airbrake resets after activation?

 

The airbrake on my 750 has a pronounced clunk when I first enable aero after starting the car. After that initial activation, it's silent during operation/deployment. I had the dealer perform a calibration when it was in for service which worked for about a week. I think it's just part of the ownership experience

 

Mine only clunks when I first enable it by pushing the Aero button. It does it's self test and I get a single clunk. Once it's engaged and moving up and down with deceleration / acceleration, there is no clunking noise. Sounds like a visit to the shop is in order.

I did have this issue with one of my 720s a few years back and the dealer needed to calibrate something and then it was fine.

 

Well said Geoff, that has been my exact experience as well. My first McLaren was the Artura with no aero brake. When I got the 750, I actually called the dealer with the same concerns indicated on this thread. Dealer said there should be just one clunk as part of the self test when starting out.

 

Just became a 750S owner and I can confirm the clunk happens a single time on activation for me as well. Glad to see that it's normal. 👍

 

Mine does the same thing.

 

Unfortunately, I am 8+ hours from the closest dealer, so unless something else major breaks, it will be a year before it goes in for service. It is strange that everyone recognizes the initial clunk during self test, which would make one think it always clunks when resets from full deployment. But perhaps wind and road noise obscures that when driving. Would someone (maybe with a spider to hear more clearly) try accelerating to 50 or mph and brake hard enough to deploy the air brake and hold the brake until the car is down to like 5 mph, at which point the air brake will go down. It’s during that movement there is one or two distinct clunks. If others’ are completely silent then I’ll just have to make a note for the shop to look at this next time it is in….

 

try accelerating to 50 or mph and brake hard enough to deploy the air brake and hold the brake until the car is down to like 5 mph, at which point the air brake will go down. It’s during that movement there is one or two distinct clunks. If others’ are completely silent then I’ll just have to make a note for the shop to look at this next time it is in….

Mine (12C, but I don't think that matters) is completely silent in normal operation like that. It only clunks -- and then, only infrequently -- during the self-test when initially beginning to move after starting the motor.

 

Mine does same - seems to be normal.

 

I remember on day one of ownership I heard the clunk for the first time... I said to myself, "you just paid 400k for a clunker." All good now that I know it's a part of the MCL experience lol.