Hello everyone, I'm out of ideas. Even the mechanics I know have never heard a similar type of sound.
Nissan Cabstar engine BD-30ti year of manufacture 1998. The sound bit like an owl - howling - blowing can be heard in the cabin and outside. I can hear it most from the space between the box and the cabin when I get out of the car on the driver’s side. But obviously also inside. On the other hand, from the same place, it is not as strong. It seems to me that this sound can also be heard from the front around the radiator. stethoscoped the pulleys, pump, etc. in the engine bay for resonance and found nothing extra. Likewise, nothing from the gearbox, the bottom of the engine. A couple of phone recording trips while driving in the areas of the differential (LSD), transmission, engine pulleys and they don’t seem to have this sound coming from them. The last recording from the space behind the cabin and it’s clear there. I can hear it even at idle, the sound does not increase significantly with the engine speed, it does not change frequency. Only in the bottom ones can he sometimes blow his horn even more. It seems constant to me, even with speed I don’t think it changes much. It sounds like slow driving in a convoy even with full power in the pull and freewheeling in a rocking rhythm. Depressing the clutch doesn’t affect it, the sound is still there. I was pretty sure it was from the diff and nothing. The most audible is around 50 km/h. Anyway, the sound is still there. Cold, warm, clutch, off, in neutral, in drive, under throttle, off throttle, etc. It’s quiet when driving without the engine (turned off while driving). I’ve already tried everything. Remove the V-belts, listen to the engine and chassis with a stethoscope, thicker oils, pressure lubrication of the cardan, check the intake and turbo hoses, check the pulleys… Also for bad Input Shaft Bearing - the noise does not change when the clutch is depressed (vehicle is stationary at idling speed)…
The visco clutch with the fan is removed today, the noise remains. I will drive the car in the evening, but I see it as a problem somewhere deeper. Crankshaft pulley bearing - harmonic balancer, or a problem somewhere with the engine timings, these are solved by gears (no belt or chain). Some ideas?
I am adding a short link to the audio recording:
Of course, I will be grateful for all opinions and ideas. perhaps someone has already encountered similar symptoms. I've personally gone through many discussion forums and videos, but to no avail. Somehow I can't get to the bottom of this sound and find out its origin.
Randall's diesels next so much noise it's hard figuring out which noise you're talking about. But you want to find the source of a noise. Just do my video finding the source of car noises. Scotty. That device or any similar device you can buy an Amazon for anywhere between 80 and $180. We'll find the source of any noise with the set of headphones and a listening device. Any noise can be pinpointed. But it's a wild guess are you're kind of a little howling noise, and that's usually a sympathetic vibration of something that is vibrating the same frequency as the engine revolution. So check all kinds of cow wings where things bolt down where they might vibrate like the hood or the air intake system
