Car suddenly noisy - do I need a mechanic?

Cavehill Red

Strange one this - I hope you guys might have some suggestions.

About two weeks ago I noticed the car was suddenly a lot noisier than before. When it hits about 25 mph, it suddenly sounds like a turbo has kicked in, and there's no noticeable difference in sound level or engine whine when I move from 2nd to 3rd or 3rd to 4th, even though the rev counter drops.
I don't think it's drinking more juice than before, but with petrol prices up, it's hard to tell.
Car is a very clean 10 year old Mondeo.
Is this something I should just ignore, or is it likely to be important? Money's tight for us all, and I'd rather not shell out for a full service if it's nothing. At the same time, I don't want to blow my engine.
In case it's not already evident, I'm no expert on cars, so I'm keen to hear opinions.

Avns1s

What mileage?

Does it vary with engine revs? Can you hear it from the engine whilst not moving?

Perhaps the gearbox or a wheel bearing if the answers to the above are negative.

Could of course be something caught underneath or in the brake disks.

Nissan doctor

Without wanting come accross as being smart, but if you have something wrong with your car and you don't know what it is, or how to fix it, then yes, you need a mechanic.

Without hearing the noise it could be several things from an exhaust issue to a failing wheel bearing.

Cavehill Red

Hi, thanks for the comments. To clarify, the car sounds as normal, just much louder than before. It increases with speed, and the tone of the whine doesn't noticeably change even when I go up a gear.
There's no noise when stationary. It only seems to kick in above 25 mph.
Car's got about 75,000 miles on it.

Nissan doctor

Cavehill Red wrote: »

Hi, thanks for the comments. To clarify, the car sounds as normal, just much louder than before. It increases with speed, and the tone of the whine doesn't noticeably change even when I go up a gear.
There's no noise when stationary. It only seems to kick in above 25 mph.
Car's got about 75,000 miles on it.

Well if its not changing with the engine RPM then it has to be a part of the rotating mass, so drive shaft, cv joint, brakes, wheels tyres and wheel bearings, with wheel bearings probably being closer to what you are describing.

Avns1s

Cavehill Red wrote: »

It increases with speed,

I take it that it is roadspeed as opposed to engine speed you are referring to.

Sounds like a wheelbearing.

Cavehill Red

Ta for that. I guess it's time to visit the mechanic so.

Nissan doctor

Well, since your in the DIY section why not check it your self.

Just jack up each wheel in turn, hold the top and bottom of the wheel and try to rock it. Then spin the wheel as quick as you can by hand.

If, when you rock it you get movement back and forward or when you spin the wheel you hear a rough rotating noise(a very slight rubbing noise from the pads/disks is normal) then the wheel bearing on that wheel is gone.

If you do hear a noise then compare it to the same wheel on the other side if your not certain.

Cavehill Red

I'd just be surprised if it was the wheel bearings, as those wheels are only about a year old. I'll give that a check.

Avns1s

Cavehill Red wrote: »

I'd just be surprised if it was the wheel bearings, as those wheels are only about a year old. I'll give that a check.

Sorry mate but I think you really need to bring it to a mechanic! (Not meant to sound sarcastic by the way!)

Nissan doctor

Cavehill Red wrote: »

I'd just be surprised if it was the wheel bearings, as those wheels are only about a year old. I'll give that a check.

All 4?

Avns1s

Nissan doctor wrote: »

All 4?

Tyres perhaps.

Nissan doctor

Avns1s wrote: »

Tyres perhaps.

I assumed he had mistyped and ment the wheel bearings were only a year old.

@OP if you ment the wheels were only a year old, I'm guessing that you don't realise that the age of the wheels or tyres or whatever you ment has no connection whatsoever with the wheel bearings?

Cavehill Red

All four wheels are only a year old. Tyres too.

Edit: Also wondering why the title has been changed. I only have the one car. I don't have an 'other car'.

Nissan doctor

Cavehill Red wrote: »

All four wheels are only a year old. Tyres too.

Edit: Also wondering why the title has been changed. I only have the one car. I don't have an 'other car'.

As said, that has nothing whatseover to do with the wheel bearings..

Cavehill Red

Was indeed a wheel bearing, which was very badly gone, dangerously so, according to the mechanic.

Thanks to everyone for identifying the problem and encouraging me to get it sorted. All fine again now - car purring along nicely.

Tea drinker

And thanks for updating the thread, always good to know what these things turn out to be.

Happy motoring!