Harmonic Hum Through Air Box; 2007 Diesel 2.0L

[Spiderous]

Hi,

I'm new to the forum and have almost no mechanical knowledge, so please be gentle! I'm hoping I can benefit from the advice and experience of others here.

I own a 2007 D4D 2.0 TR; only 49,000 miles and full service history. It was last serviced about 4,000 miles ago It's developed a noise which is difficult to describe, but I'll do my best.......

When pressing the throttle to increase the revs, I get what can best be described as a "hum", at between about 1,400 and 1,600 revs. This stops when you get beyond this range, but returns briefly when you take your foot off the throttle, including when changing gear. The noise occurs both when the vehicle is in neutral and in gear. There are no EMS or other warning lights visible on the dash. The sound is coming from the airbox area of the engine compartment.

I took it in to my local garage to have it checked over. The exhaust is fine. They found that when they removed the air filter the noise was much lees audible, so concluded that something, somewhere is resonating at a certain frequency with the airbox with the air filter in place. They detected no reduction in performance and can find no obvious fault. They suggested I try the web to see if it's something any other users have experience of or ideas as to the cause.

Any help anyone can provide is greatly appreciated.

Cheers,

Ian

[Siri]

Hi

I had a similar problem. There is a piece of foam which surrounds the "pipe" from the airbox. If this has deterioated the pipe begins to rattle against the airbox at certain revs particularly when stationary.

You may need to replace the foam. I had it replaced under warranty but you maybe able to do a diy job on it assuming it is a similar problem. This was about three years ago so cannot remember the exact details (2007 d4d avensis)

Hope this helps

[t-spiritpete]

Hello and welcome,

I'm very suprised that you garage was so close to the problem but never solved it, the problem is caused by the foam seal between the plastic air intake pipe and the air box itself. The air box needs removing first by taking the top off, the filter out revealing the screws holding the box in place to the chassis, remove the large rubber hose taking care not to damage the wiring to the air mass sensor. When you slide the airbox out you will see the problem and this can be solved using some foam or double sided foam tape like I have used on mine. Reassemble which can be quite tight with that new foam and as an option you can put a short self tapping screw in to hold the airbox to the plastic pipe at the top ...... JOB DONE, no more noise!

EDIT sorry Sanjaya I replied just after you mate.

Regards,

Pete.

[Spiderous]

That's absolutely great. Thanks for the response guys!

[Devon Aygo]

As posted above wrap the air intake pipe in foam to prevent the noise:

[aadams11]

Hi everyone this is my first post here. Spiderous ,did u solve "hum" problem u were experiencing?Just bought same 2007 D4D 2.0 TR with 49000 miles with full Toyota history.What a coincidence just like yours.Few days ago I noticed this noise at low rpm.I own car just 2 weeks and didnt hear any unusual noises first week.Its most noticeable when gently pressing the throttle to increase the revs.You can still hear it during driving. This low frequency "hum" does irritate me.Garage will look at it next Tuesday as it is under warranty ,Hope its just that foam issue.Guys thanks for useful info and picture.Will feed back once car back from garage

[Spiderous]

Hi,

yes I did; the problem, and the solution to it, we're exactly as described by the good folks here. I took the schematic kindly provided by Devon Aygo to my local garage and they sorted it out. If you are in any way handy I suspect its an easy fix to do yourself, but if you're under warranty you may as well get them to do it.

[aadams11]

Hi yesterday i picked my toyota from garage after a week.

They fixed that "hum" noise by replacing sealing foam tape on plastic pipe inside air box.Did show them picture of what needs to be done.So really pleased.It seems like common fault as it looks.Engine had knocking sound while cold first 2 miles.They replaced all injectors as they had some prob with tips.That saved me a couple hundred pounds.Thanks u all

[magicdrshoon]

Excellent! I have the same issue with my '08 T180.

Thanks!

[Killian Lobato]

I have the same issue. When I did find time to dismount the tube I did manage to see that the foam had all gone. Unfortunately, I did not have foam at hand to get the job done properly! When I do, i'll report back.

[frankie406]

You can buy a cloth type tape from eBay that will help