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I noticed the following problem:

There's a noise coming from the engine bay (possibly the engine?) when I accelerate hard while making a left turn.

My car is a 2007 Jaguar S-Type, with rear traction and automatic transmission. The noise is not present on right turns, only on left ones.

Also the noise is only present when I accelerate (at least 50%), if I let the acceleration pedal there's no noise anymore.

What could it be? What should I check first?

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    Is the sound central to the front? Or to one side? And what kind of noise? A thrum, rattle, grinding, whooshing, squeaking, puffing etc... It's unlikely to be the engine given a specific side, but then could be a lack of oil on pick up (if you're reall
    – RemarkLima
    Dec 16, 2018 at 17:41
  • It's not central and it's definitely coming from the right side. I would describe the noise to be more like a rattle/grinding one. Engine oil level is fine, and I know for sure that I have two bad things: bad rear differential (low on oil, it "whines" at specific speeds), and some bad front-suspension bushings.
    – mariusmmg2
    Dec 17, 2018 at 8:27
  • Well, if its front right then you can rule out clutch, gearbox, prop, diff, CV joints etc... But it could be a wheel bearing most likely, from the noise you described.
    – RemarkLima
    Dec 17, 2018 at 8:50

2 Answers 2

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One strong possibility is you have something loose which is rubbing against a tire. It could be a piece garbage you ran over which got caught, a loose cable or hose which moves under acceleration or maybe a piece of loose body trim. A visual inspection of the engine bay and wheel wells in the front is a start, it may be pretty obvious. Check for grooves or damage on a tire sidewall as that is a giveaway. Wiggle things around, and if you find the culprit secure it.

If something has been rubbing on a tire check it thoroughly, rubbing can weaken sidewalls and cause tire failure.

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  • Tires are fine, thy're not rubbing. Could this be suspension related? I know for sure that I have at least one bushing that is shot (left side, on the wishbone arm, it's the one that connects the shock absorber). Thanks!
    – mariusmmg2
    Dec 14, 2018 at 11:05
  • How do you know the tires aren't rubbing @MariusMarusanici? Generally a worn suspension bushing will cause a constant rattle when going over bumps, I wouldn't expect to only hear it under acceleration.
    – GdD
    Dec 14, 2018 at 11:19
  • There's no sign of rubber damage on the tires, also everything looks in place, at least from a visual inspection without lifting the car up.
    – mariusmmg2
    Dec 14, 2018 at 12:14
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From you comments, we can summarise that:

  • The noise is from the front right
  • It only occurs under acceleration on left turns, i.e. your loading up the right hand side of the car
  • The noise is a rattle / grinding
  • You know you have some iffy front bushings

A "wub wub" or grumbling noise can sometimes be a wheel bearing, and this is easy to check. If you jack the car up so the front right wheel is in the air, hold the wheel and tyre at 12 O'Clock and 6 O'Clock. Then try to push it in at the top and pull out at the bottom and visa versa. This should be solid, however if there's significant movement then you have a bad bearing, or something is up with the hub.

As you say you have some bad bushings up front, these could be the rattle / grinding noise. Remember their job is to allow movement of the wishbones to the chassis and if worn will allow the wishbone to move too much, and potentially rub into some chassis or bodywork. I've had a car where under heavy breaking the steering wheel felt like it was going to fall off it moved so much! All down to a pair of wishbone bushes.

Also, remember that whilst you can push and pull, and think there's no lose body work etc... At 100 kmph, with 1.6 ton of metal pushing things around, there's a lot more weight and movement than you may think!

I'd first check for the wheel bearing, followed by the front bushes, the ARB bushes, and any play in the steering rack.

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