Hello everyone, and it's a great relief to be accepted on this great forum. I have a 2012 Equinox 2.4L. Two days ago, I carefully cleaned the intake manifold port and reassembled everything, and it seemed fine. But the next day, after driving for a few hours, I heard a suction sound, like a vacuum or something similar. I decided to remove the oil dipstick, and the sound disappeared. However, I then realized that the same sound was coming from the oil filler cap. When I disconnect the hose that runs from the valve cover to the intake manifold, there's a lot of suction. Because of this, I'm getting code P0171. Has anyone else experienced something like this? I've done some research, and I think it's the valve cover and the internal PCV system. But I need advice from someone with experience.
Excessive suction
- Thread starter Luis
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
I don't think so. I did it with a small screwdriver that fit right there in the hole, and then with cleaner and hair.
Normal to have some amount of suction in the pcv tube that goes from the air box to the valve cover. Check that hose for a leak. The flexible rubber part that goes onto the valve cover can rip. But if there’s an unusual amount of suction, I suspect you made the hole for the PCV orifice too big.
It's possible I enlarged it without realizing, but I didn't feel any resistance when cleaning it. I'll try putting some wire in to test it, and if it improves, I'll have no choice but to buy a new manifold. Thanks, I'll let you know how it goes soon.
Similarly, I repaired the oil dipstick tube and the hose that runs from the valve cover, but I just put a half-millimeter wire in it and sealed everything well and waited for it to heat up. I think it's fixed because the pressure in the MAF sensor decreased and now it's giving a normal reading. I'll wait for the glue to dry completely before testing it properly.
cpscoachtech
New member
- Joined
- Feb 17, 2025
- Messages
- 4
- Reaction score
- 0
I recently had my manifold off and cleaned it and decided to make it just a wee bit larger hole. I believe I went too big and it started the whirring sound. Quite annoying. Not sure what to do other than remove the manifold and drill a smaller hole into a small piece of metal and jb weld it over the larger hole to stop the vacuum. I put the old unvented oil cap back on and the noise subsided. Now I wonder what issues could be happening. Should I go back to the oil catch can I have installed and repair the pcv hole on manifold or leave it as is? Ironically, I think it was worse because I was changing the timing chain and guides at the same time and I put the main seal on the "harmonic balancer" backwards. So the pressure was building and a 2 hour drive pushed all my oil out of the seal. So, larger pcv and seal that was not sealing on the main equaled lots of noise. Yeah, I feel stupid but I didn't know which way it was suppsoed to sit. Makes sense now. Live and learn I suppose. 2013 Nox with 2.4l Ecotec.
