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Matt, Mechanical Engineer
Category: Toyota
Satisfied Customers: 22747
Experience:  BEng hons Mech engineering, in auto industry 22 years
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my 2004 rav 4 d4d has a engine noise hum kind of in any gear

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my 2004 rav 4 d4d has a engine noise hum kind of in any gear when it is between 2000 and 3000 revs , my local garage thinks it is where the turbo
is . only had the car a month its only done 70,000 miles how do i know if turbo is on the way out have R.A.C so called warranty up to £500 per incident by the way it doesn't do this when still and revving in neutral any advice welcome as already changed fuel filter and rear brake pads ( not covered on so called warranty
kindly annette

you can feel for any wear by removing the high pressure intake hose after the turbo and have a feel of the turbine wheel - there should be no play radially at all - but a little bit of axial / end to end float is normal

also if the turbo is on the way out then you may have low boost pressure and low power

if the car doesn't feel down on power then I'd try removing the auxiliary drive belt and turning every pulley and ancillary ( power steering pump , alternator etc) by hand. All should turn easily (with the exception of the AC pump) with no grittyness or wobbly pulleys- If you do find a sticky pump / alternator then it should be replaced or repaired
If the engine is stone cold you can briefly run it with no belts to see if the noise changes or has gone away, this will help show if an ancillary is the issue

Examine carefully the condition of the bottom / crank pulley as these are composite construction with a rubber element and its possible this rubber is breaking up and allowing the two metal portions to move.

Another possibility is the variable valve timing system as this does rely on oil pressure to correctly synchronise your vvti pulley on the end of the camshaft. If the valve has become blocked up then its possible the pulley is rattling about and producing the noise.

If all of this is OK then its possible the issue is with the dual mass flywheel on the other end of the engine, these are constructed in the same way I mentioned for the front pulley but are more prone to problems due to greater heat and larger forces.

If your gearstick is rattling this is another pointer to this being the problem

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