I got my XK X150 (2008 4.2 litre) about 2 and a half years ago. It had 18" wheels from the factory, the previous owner upgraded to 20". It had some cheap tyres on it when I got it, but at least they were brand new so I left them on. In May I got Jaguar to do a bunch of work - replacing a failed parking brake actuator, and replacing some suspension bushings (which meant replacing entire arms since Jaguar don't supply the bushings by themselves). And as part of that work, I got them to replace all four tyres with the spec it came from the factory with - Dunlop Sportmaxx.
When I got the car back after all this work (about £6,400 worth of work in all) I didn't notice anything at first, but then on a warm day with the windows down, there was a very noticeable noise coming from the rear of the car. It is very difficult to describe - not quite like metal scraping on metal, but not entirely unlike that. Or a bit like the whistling sound when you blow over the top of an open bottle (but not actually whistling, just a smooth windy noise). It isn't massively disturbing, in fact I didn't notice it for the first few weeks. Having lived with it for a few months now, it seems more pronounced during warm weather.
I took the car back,the one engineer they have who's old enough to be trained on the XK couldn't hear anything on a road test (but I suspect given a combination of age and work environment, his hearing understandably isn't the most acute!). He took it back into the workshop, and adjusted the disc heat-shield on the fronts, and I got the car back. It was immediately still noticeably there, so I took it back, and they very good naturedly took it back again, gave it another inspection, and again fettled the front disc heat shields. Yet it's still no better. And it seems difficult to address when I can't show that the sound wasn't their before, and their one qualified engineer simply cannot hear it at all.
Today, being a warm and still day, I took the car out onto the A555 (a good condition dual carriageway), and at 70mph at 2,000 RPM in Drive, with the windows up, radio off and the fan off, I realised a nice and simple test,which should work for anybody regardless of how good their hearing is. At 70mph you should not need to raise your voice in order to continue a regular conversation with a passenger. We did have to raise our voices a notch in order to continue the conversation. That was definitely not the case before I had Jaguar work on the car, and I would not expect that of a Jaguar (or even a much cheaper car).
So - to cut to the questions:
When I got the car back after all this work (about £6,400 worth of work in all) I didn't notice anything at first, but then on a warm day with the windows down, there was a very noticeable noise coming from the rear of the car. It is very difficult to describe - not quite like metal scraping on metal, but not entirely unlike that. Or a bit like the whistling sound when you blow over the top of an open bottle (but not actually whistling, just a smooth windy noise). It isn't massively disturbing, in fact I didn't notice it for the first few weeks. Having lived with it for a few months now, it seems more pronounced during warm weather.
I took the car back,the one engineer they have who's old enough to be trained on the XK couldn't hear anything on a road test (but I suspect given a combination of age and work environment, his hearing understandably isn't the most acute!). He took it back into the workshop, and adjusted the disc heat-shield on the fronts, and I got the car back. It was immediately still noticeably there, so I took it back, and they very good naturedly took it back again, gave it another inspection, and again fettled the front disc heat shields. Yet it's still no better. And it seems difficult to address when I can't show that the sound wasn't their before, and their one qualified engineer simply cannot hear it at all.
Today, being a warm and still day, I took the car out onto the A555 (a good condition dual carriageway), and at 70mph at 2,000 RPM in Drive, with the windows up, radio off and the fan off, I realised a nice and simple test,which should work for anybody regardless of how good their hearing is. At 70mph you should not need to raise your voice in order to continue a regular conversation with a passenger. We did have to raise our voices a notch in order to continue the conversation. That was definitely not the case before I had Jaguar work on the car, and I would not expect that of a Jaguar (or even a much cheaper car).
So - to cut to the questions:
- Does this seem a reasonable test, and a reasonable expectation for a luxury car (albeit 18 years old now) on brand-new tyres on a good road surface?
- Could it be the fault of the tyres? Are the Dunlop Sportmaxx really just quite a loud tyre and I should expect this inconvenience as compared to a no-brand tyre?
