Anybody else with an 8 speed auto experience a clunk at exactly 9mph when accelerating slowly after starting their car? Only does it after starting the car. Won't even do it after accelerating from an eco stop/start either. Repeatable every time. Maybe it always did it, I just never noticed since I don't typically accelerate slowly

 

It might be the drive away locking feature - you can set it in the options on the touch-screen and I think it can be set to lock at 5mph, 10mph and 15mph. It creates a bit of a 'clunk' noise as you're driving away and sounds like it could be your noise?

 

No. Not normal.

 

No, not the locking feature. It's set to 5mph and sounds different. This clunk is definitely coming from the transmission tunnel area. It's a quiet sound but I can hear and slightly feel it through the gas pedal at exactly 9mph.

 

I'm experiencing this as well actually. I never tracked the exact speed that it occurred at though.

 

It sounds like the EPB (electronic park brake) which may release in that fashion. It may have something to do with the self adjusting feature of the e brake but I don't know. The electric mechanism is where you hear that sound coming from even though the actual brakes are at the rear of the car of course.

My '09 gave a clunk like that when first starting off after being parked and not otherwise. My 2013 does not.

Ask your dealer about it.

 

Does your year have dynamic mode? If so, does the clunk happen the same with it on and off?

 

Only the 09 supercharged had dynamic mode I believe. The clunk only occurs right after start up when the vehicle has been parked for some time.

I'm assuming the OPs XF is the 4.2 NA as well

 

8 spd was introduced for 2012 (?) or 2013. The 4.2 only came with the 6 spd.

 

If I start the car and back out of a parking space (so the park-assist beeping is on and radio vol is reduced) and then start to drive away, I feel something like that at around the point at which the park assist turns off and the radio comes back to full volume. It's not very strong, but definitely noticable. Does yours recur if you reverse then start driving again?

 

I've had the same issue since I purchased the car (09 SC XF). The dealer could never replicate it when I brought it in. My clunk is pretty abrupt and only happens in that 9mph range when the car is cold and has been sitting for a few hours. The more load it's under the more noticeable it is. I have to baby it for about 10-12 seconds when I first drive off and then it's fine after that. It bothers me quite a bit. I was thinking of having the trans flushed but that electronic parking break releasing is interesting. I never engage it though.

 

Use the button on the headliner to turn off the park assist earlier and see if it's still related to the clunk.

 

Ah you're right. It said 8 spd trans right in the thread title lol

 

Tried all of the above. I get the noise whether dynamic, park assist, or not. I do not get it if after the noise, I repark, leave car running, backup again, then roll away. Not the electronic park brake. It's nearly silent on my car. I'll let the dealer know when I bring it in for an oil change in a month or so and post what the verdict is. I was just curious if mine was the only one doing this.

 

Let us know if you learn what it is. I have the 6-sp transmission in the 2010 XF SC and I get exactly the same thing

 

To clarify are people just hearing a noise or does the car physically shift hard/abrupt? The posts above comment on a noise so I wanted to be sure. Mine (6 speed) has always been a abrupt shift that jerks the car and it's much worse under any type of load. It's only the very first shift after a long period of time.

 

If you have the 6 speed ZF you might be feeling the "Lurch".

Very well documented and it occurs in several forms. I got rid of most of it with a TCM flash to the latest software.

Jaguar S-Type Ownership Experience - The ZF LURCH Fault
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It's a noise and brief vibration felt through the gas pedal at 9mph. The car is not shifting when it occurs. I verified by starting the car, backing out, then put trans in sport and car in dynamic mode and used the paddle shifters to lock in first gear. Still does it at 9mph. Maybe "clunk" isn't the correct word for the sound. It's kind of like the sound when traction control kicks in, but it's coming from the transmission tunnel area. My car is RWD. Too faint for my cell phone camera to pickup. Could be normal. I had a new Accord that lurched when you let off the gas at slow speeds. Very annoying in stop/go traffic. If this sound is normal, I can live with it.