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Engine noise and shaking over 70kmh

Hello I’m new here and this is my Jaguar XF, 2014, 3.0L Supercharged. I don’t know much about cars, so here I am to get some help!

Lately it has been having vibrations and some noise issues so I changed the tires, wheel bearing, all bushings, motor mounts and the trans mount. Also the alignment was done. After all this, when I still have some vibrations at speeds higher than 60kmh and the engine is still loud (or I think it is, kind of lost sense of what is normal).

Please see the video and let me know what you think about:

i) in general the engine sound while it is at D and brake is pressed,
ii) the whole shake at the end when I ask my wife to stop the car,
iii) also not in the video but why would it still be vibrating at 60+ kmh?

I just don’t trust the mechanics around here, that is why I am asking here…

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Its difficult to diagnose this type of problem on the internet.You need to seek professional help.We are only guessing here.

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you don’t trust mechanics that are near you, but you’ll trust complete strangers on the internet?

Have you had the tires checked/balanced? Were all those parts you replaced bad? Or just guessing at why it vibrates?

Does it do that regardless if the engine is hot or cold?

Yes because strangers won’t make money when they say “you need to change this and that part”.

The parts that I replaced were told bad by two different mechanics, so i assume yes. And it did help, the vibration is while idle or below 60 is gone and the whirring sound is also gone.

Yes it does. The video was when it was cold.

Shaking noticed when applying the brakes with the car in motion is often caused by warped brake rotors (discs). That’s a pretty simple thing for an experienced shop-tech to check. If you don’t already have a trusted shop, ask your fellow friends, co-workers, church-goers, bar hoppers, who they use to repair their cars. Interview a few of the shop owners, being sure to tell them which of their customers recommended them to you. This gives you a little leverage when you need to use the shop the next time. They’ll be sure that you are satisfied w/the result b/c otherwise they’ll know you will be telling another of their customers about your dissatisfaction.

Vibrations noticed at 50-70 mph just driving down the road, my first suspect is a wheel that’s out of balance, or wobbling laterally, or out of round. Sometime you can get a clue by swapping the positions of the wheels and noticing whether there’s a change to the vibration or not.

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Solid advice. Thank you. I am going to get wheel balancing done today (at a tire shop recommended by a colleague) to see if that helps with vibration at higher speeds.

You got new tires? It is very common to have new tires balanced when you install them. If you did it at a pro garage than I am pretty sure they were balanced. I would look at “quality” of tires. It’s a jag. What is the brand and model of the tire. It says right in the sidewalk. Look.

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Yes new tires: Michelin Pilot Sport 4, 2019. It should be one of the best, according to the reviews I have read. And that they did do the wheel balancing when they changed it.

However, I changed the bushings, mounts etc after I changed the tires, so I am guessing the balancing needs to be re-done because all those part changes kind of messed it?

no, you do not need to balance the tires again. The work you did has nothing to do with the mounted tires.

Correct, a wheel/tire is balanced all by itself, so the “balanced or not balanced” question, that is not related to the perfection or imperfection of rest of the car’s parts. It’s possible however that an imperfection in some part of the car (other than the wheel/tire) could produce a symptom similar to an unbalanced wheel. A problematic hub is one example.

I got the tire balancing and tire pressures double checked yesterday and like you both pointed out, there was no issue there because it was done recently anyway.

Today I paid extra attention to understand where the vibration feels, I noticed that the whole ride feels like I am driving on a bumpy road albeit very small bumps even when I drive slow. I know the higway road is very smooth but it just doesn’t feel smooth and like periodic bumps all over the road and then when I go over 80-90kmh, the vibration at the steering wheel becomes noticeable.

Also probably unrelated but just recently the car started to do something manual cars do like when you don’t press the clutch enough and it feels like it will stop. This only happens at very low speeds when I am going out of this very short bumpy road with slight uphill in the morning (i.e. still cold engine though I live in a hot climate). Some googling and reading, it sounds like it may be fuel injector issue.

All of these issues (i) engine is louder than usual at idle, like diesel but very slightly ii) slightly periodic bumpy drive and vibration over 80km and iii) car struggling at low speed bumpy uphill may be totally unrelated. They all feel very minor, I mean you really need to pay attention to it, for example when my wife drives, she doesn’t feel them. However, after changing all mounts, tires, wheel bearing, bushings and shock absorbers (total about $2.3k) things are still not as smooth as I would like and may be it is negligible but still drives me crazy.

The jag forums say the clunk at motor stop is a bad supercharger drive wheel. It has a spring inside. There is even a solid version. But that is a slight noise rattle issue. Not so much a drive issue. You start reading about build quality on these jags and want to run.

I had a VW Rabbit years ago that developed a problem where it felt like I was driving on a very rough road surface. Not like there were big ruts in the road, but more like lots of tiny bumps. Similar to driving on a road where the road crew had used one of those machines that roughens the surface prior to resurfacing. There was a vibration felt in the steering wheel, and a growling noise. That problem turned out to be faulty front wheel bearings.

The wheel bearing was the first thing that got replaced, while it did help with the whirring noise I had, it didn’t solve the other problems.

I left the car to the dealer today, tomorrow they will give me a call with what they find and a quote. They are charging $250!!! for the check if I decide to not do the work there. I am hoping they won’t ask me to pay it if I at least do some of the cheaper work there…

It has been a while and the problem is still not totally solved. Here is the latest update:

  • Took the car to the dealer, who said they found an issue with supercharger belt or something like that and fixed it, plus they rebalanced the tires again and the car should be fine now.
  • I took the car and drove it around and the vibration at higher speeds was still there.
  • I took it to a highly reviewed tire shop to check the rims, balancing etc, they checked and confirmed all is fine. No bent rims etc.
  • Next, I took it to a independent garage for diagnostics who charges $100, they kept the car for a day, tested everything, then they said this: “we checked everything but we couldnt find any issue, however when we drive, we also feel the vibration”, only dealer or more specialized Jaguar garages can figure it out and didn’t charge me the diagnostics fee… They said the joints etc are all look okay.

So I am stuck again. The vibration is mild but incredibly annoying to me. It also feels like I am driving on tiny bumps all the time whenever I drive over 70-80 kmh. The vibration gets worse as the speed increases and if I take it to Neutral when I am driving on highway, the vibration is still there (I don’t understand much about cars, I’d imagine this should rule out at least some of the potential issues).

I am going to try another garage I guess, cannot think of what else to do. On the bright side, I was wrong to not trust the garages, they didn’t try to make me spend money for issues that dont exist and were honest.