Pulsating-like sound coming from engine at high speeds

[subordinate]

I have a weird problem, and can't seem to identify it.

It's a deep pulsating sound that comes on periodically from the engine bay at high speeds, I also think it is linked to the heater. Trying to remember, I have always had the heater on, when these surging/pulsating noise came on at higher speeds.

Any ideas to what my problem could be?


There are no changes the car's operation, just the sound is very noticeable.

[godwin]

air lock? Heater core? water pump?

[Akira@Rise]

depending on the age of the car, it could be the blower motor?

[subordinate]

I haven't solved the problem yet, but it can also be possibly that the a/c needs to be recharged.

But the blower motor, I will definitely check that out as well.