What is your persona mileage?

The humming sound from the back.. only happen after driving > 60km/h? Fuel smell... only when you start up? or after running quite a while you stop down also still be there? Have you change your fuel filter? and check on your exzos see got bocor or not.

Humming might be ball bearing worn out at the rear wheels, or brake bengkok. But since you say noise gone once you step clutch, might be something connecting the drive shaft & gear, but can't be since they are at the front. There's nothing at the back... Anyway i don't understand the humming is front or back since you say front then say back. Front might be timing belt, AC, fan, bearings etc just open up your boot and listen.

The fume, do you smell it when car is turned off? If yes probably gas tank small crack when gas escape. If only when engine on maybe you are running rich, maybe o2 sensor broken, maybe some sparkplug broken so it did not ignite during that cycle.

Do you feel any power drop etc when driving?

Send it to service center to check further.

How can it be from the engine if only Rear passenger can hear??? If from engine might be knocking. Can you feel the vibration sitting infront? Do you hear the sound when car is idle? If you say sound happens when clutch is connected to wheels, might be drive shaft axle, gear but all these are located at the front portion of the car. If rear might be exhaust got holes, but doesn't make sense with the clutch.

It might also be clutch problem since you say it's getting hard & happens when clutch is engaged (connected), read this:
http://www.rangeracceleration.com/Clutch_Care.html

O2 sensor cannot check urself. Maybe SC can check by using computer tapping to ECU, if not have to take out and i dunno how they gonna check. Most likely they will just replace it and see got problem or not, at your cost lo. If not might be ECU problem or injector problem.

Your problem can be minor or major, do they occur the same time or 1 after next? This can help tell you whether the 2 problems are related.

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Added on November 16, 2012, 11:53 pmI initially though it was bearing, but bearing sound is like wooo, woooo, woooo, TS is like degung degung like something banging hard.

Which is which?

Base on the description of your passenger I'm pretty sure there is some issue with your wheel bearing. Get it check in the nearest rim/mech/tyre shop. Usually when the humming is too noisy it's most probably because of the worn out bearing and at 9x,xxxk km.. It's most probably be it. Driving at low speed there isn't any loud noise from the back right?

Have you tried different petrol and see? Are they giving you the heavy fume smell? I assume you only go for Esso or Petron?

degung degung conform not tyre problem. something is banging since it dissappears when clutch is pressed.

can also be suspension broke so something is hitting but cannot be if like that TS won't still be driving the car.

since he say clutch press no more sound we focus on the connected parts.

either that or engine knock, or outlet valve problem causing fuel to leak to exhaust.

TS never tell us whether the car suffer any power drop or not, just tell us mileage ok.

If it's a Wooo it's the bearing la, i've sat in a taxi the driver told me it's the bearing.

Could be the tyre as well. Uneven tyre surface could make farny ound at high speed also.

Using gear 5 is not straining the engine, using gear 1 is. The bearing wooo usually happens after certain speed.

Your description doesn't tally, as you can't get high speed uphill with 5th gear.

If you can't hear it at the front but people can at the rear, no way it's coming from the front right? Unless you continuously fart.

Then i dunno why got fuel smell. Usually if running rich or poor, you will suffer power drop due to imbalance mixture. Maybe u exaggerated the fuel smell strength and it's only slightly rich?

at 5th gear the engine load on the wheels are very minor compared to lower gears, most likely your rpm will be also low, so maybe the wheel is not being driven enough by the engine which causes more friction by broken/badly installed bearings? I assume you 5th gear 60km/h for a steady stretch and at 4th gear same speed uphill less noticeable. But in order to maintain same speed on higher gear you have to tekan minyak more. Have to rule out sound coming from front anyway.

You sure fuel smell come from exhaust not other parts of car like fuel tank? Like i said might be fuel tank top cracked so gas escaped, or engine outlet valve is passing fuel before they got fully ignited but then you'd hear banging noise & loose power. No fuel leak?

bearing usually last quite long, but maybe faulty bearing or wrongly installed.

From what TS said.. Doesn't sound like wheels bearing problem at all...

axsatr,

Your vibration @ 100km/h is caused by a missing drive shaft damper, which was not installed in certain units of the first batch 2007, non-iafm model. This is caused by different suppliers for the drive shafts; some had the damper installed and some not. You can find very good posts in motortrader forum, search for "persona drive shaft damper". This problem has been solved in later batches afaik. The symptom is pronounced pedal foot vibration at 100km/h only; more than or less than the speed you don't get the vibration.

I see the car is getting old; it's a good car while it's new but after you have done some mileage on it you can see how badly it's made. Changed mine - you should cut your loss while still can.

Have you checked the rear bearings? Coz i doubt the sound comes from front.

Tyre even noisy won't give the kind of sound you described. How's the sound now?

Even cold start should not smell like fuel.