My 2006 LR3 with V8 4.4 liter engine started to make odd noise when the gas pedal is pressed that I can only describe as "buzz saw" like noise. (from inside the cabin, it sounds more like a whining noise)
The engine will make this noise when I start the engine and slowly fade away as the RPM levels, but I will hear the sound again every-time I press the gas pedal.
And now I can confidently say that it is getting worse by the day.

Here is the link to a short video showing the engine running. you will be able hear this noise as soon as I step on the gas pedal at around 4 second mark.




To me, it looks like it is coming from the pulley or the front/upper side of the engine but I am not too sure.
I tried using a long screw driver to identify where this noise is coming from without any success.

I have already replaced:
-Alternator
-Idler pulley (one on the left hand side when standing in front of the car)

Since I can hear the noise when the car is parked, so it cannot be the wheel bearing.
I have replaced one of the wheel bearing, and they sound very different when they are going bad.

I am wondering if anyone had a similar experience?

 

Hmmmm......this is a new one for me. 17.5 years of ownership and being on multiple message boards consistently and I haven't heard the "chainsaw" noise yet. Any noticeable behavioral differences?

 

Not so far, the car drives perfectly fine. Just the annoying noise (from inside the car it sounds like whining noise) when I press the gas pedal.
it is slowing getting worse. (noticeably louder)

Thinking about removing the fan/belts and start the engine to make sure it is not coming from one of the pulleys, but I am struggling getting the fan clutch off even with the pulley holder.

 

Well I am sure you know the fan is reverse thread? If not, you do now! Either way, they can be brutal to remove. Make sure you use anti-seize on it when installing again and don't goo too tight - the engine will self-tighten it. I would indeed remove as much as you can and spin everything by hand. Could be anything really at thing point. Tend to think water pump maybe though....

 

I have managed to loosen the fan with some persuasion and brutal force.
I think you are right about the water pump. I have found a Youtube video posted by ZipZpDIY and his car is making the exact same noise that my LR3 is making now.

 

I have solved this issue. It was the water pump. If you can remove the fan, everything from there on is not too difficult.
One thing to note though, I initially bought the improved one piece water pump which did not work for me. It took me hours removing/reinstalling the water pump due to a major coolant leak.
Thinking about it now, this 1 piece design has a large rubber ring where the water pump goes into the engine and I think this rubber ring wast not seated properly, causing the leak.
I ended up paying more for the 2 piece design and everything worked out without any issue.


comparing the old water pump with the 1 piece water pump.