Hey all, this is my first time on this site, so apologies if I mess anything up.
My g37 has just recently been making a very loud and high pitched squeel/whistle after running for a short period of time, around 30 seconds. The noise can be traced to the dipstick, as removing it will release a vacuum, and promptly halts the noise.
A friend said it may have been the pcv valves, but after removing and cleaning them(they rattle freely), the noise is still there, although maybe slightly quieter. Any ideas as to what the problem might be?