Strange whistling and diesel sound
 

Again, im sorry because im writing in english....

Now when winter is almost passed, i noticed that my Applause has very strange sound. It has some whistling sound, like on turbo diesel engines. Ive noticed that sound on vw 1.9tdi motors(Octavia, golf, etc.)... Its very noticeable when in neutral.

And ive noticed that it has a bit diesel sound. SOme friend told me that thats common on japanise engines which have VVT system. Ive been trying to find does appi have it. I found that the f300 has DVVT, but is the f300 same as one in the Appi. If that was the problem, i would have to chage the camshaft?

What could be the cause. Again sorry....

Applause Engines (HD-E typed) don't have a VVT-System.
The Engine sonds rough when cold-started (noise like a blown crankshaft/rod bearing) this noise disappears after several minutes. When cold particulaly this engine shouldn't be reved to high to prevent bearing damage.
The whistle sounds comes probably from the throttle body

Noise isnt nothing like when strated cold. Still can in be the camshaft because of the rough sound?

The whisteling sound really comes from throtle body, should i be worried?

No, if there`s no problem with changing engine speed in neutral it should be ok.

Hmmm... maybe you should take a look at the valve's clearance (to control when engines hot) this should be about 0.15mm for the intake and 0.35mm for the exaust valves. In case of clearence's mismatch take a good look at the camshaft for abrasive wear. If the clearence's mismatch is in a extreme range (no clearance at all) you should take of the rocker arms and control them for wear too. For the screw's torque I will take a look at the Repair manual.