[13cruzeJ]

Hello all,

Just the other day my 13 Cruze 1.4 starting making a high pitched chirping noise. I thought it was the A/C compressor bearing but the noise persists regardless of whether its on or not. It is definitely coming from the accesory side of the engine. Heres the weird part though. When trying different things to determine where it was coming from, I pulled the filler cap to see if it was valvetrain related and the noise went away. Normal when you do this, the engine will drop in rpm and stutter ( because of there being a vaccum leak via the pcv system) Now when I do it, the noise goes away and the engine runs like it should. Upon replacing it, the noise returns immediately and usually its louder than before. Also, if I momentarily plug the small pcv breather hole under the coil cover, the noise gets a lot worse. This really has me stumped because it appears to come from the accesory area but the whole vaccum thing having an effect on it is really causing me to scratch my head. I'd prefer to not take it to a dealership as the car isn't under warranty anymore and I am very mechanically inclined. Just wanting to bounce some ideas around to help me locate and fix the problem. Thanks guys.

 

[jblackburn]

Good diagnostic.

Should be under powertrain warranty still if you're not over 100k. The crankshaft seal is leaking crankcase pressure & making the noise.

While you're at it, pull off the corrugated hose to the top of the intake manifold. There should be an orange dot visible in there - that's the PCV system check valve. If it's missing, the intake manifold needs to be replaced as well

 

[ChevyGuy]

I pulled the filler cap to see if it was valvetrain related and the noise went away.

PCV malfunction. It's causing the engine to become pressurized and the pressure is escaping through the cam seals. Removing the cap releases the pressure.

It's covered by the 5 year/100K mile powertrain warranty.

 

[13cruzeJ]

That completely makes sense. I can feel crankcase pressure coming out the filler hole too. Well since I'm only at 43,xxx miles, I'll be calling and making an appointment at the dealership in the morning. Thanks for the help guys

 

[13cruzeJ]

Took the car to the dealership today. Ended up being the PCV. Of course they had to replace the valve cover because its integral but it was covered under warranty. Thanks for the help guys.