squealing sound in engine. Vacuum at Dip stick
About a month ago my 1999 dodge ram 1500 ,318, (5.2 liter) started making this whirling noise, squealing, or whistling noise deep in the motor., At first I changed out the belt thinking that was the problem, it wasn't.
Yesterday while adding oil to the engine I noticed a massive suction at the oil cap. When the cap was off the noise stopped, when I replaced the cap it started again. the same for the PCV valve, if I removed it, the noise stopped. I replaced the PCV valve, noise still loud. The same goes for the dipstick tube, a lot of vacuum, once I pull it out, noise stops.
I could not find any vacuum hose leaks, I tested and checked the air filter with no luck there.
Any help would be greatly appreciated. I have never seen anything like this.