Chevy Impala Vacuum Problems After Intake Gaskets Replaced

Question:
Had the oil changed and PCV changed late Oct. at an oil change place. Not long after the check engine light came on EGR problem. I replaced EGR and the check engine light came on again. A couple of weeks later, the low oil light came on and was down 1.5L of oil. 2002 Chevy Impala 3.8L.

My mechanic Was fixing the car for harmonic balance noise and the water pup was also noisy, and replaced the valve cover gaskets. After replacing these, he noticed a severe vacuum and found that the PCV valve o-ring was missing. Could this have caused the oil leak and EGR failure or any other damage? I am dealing with the oil change place over this.

Answer:
The missing O ring on the PCV valve caused the high vacuum condition. This is the reason for vacuum when oil fill cap removed, and the oil being low. Not a pressure problem to cause leaking oil, but a PCV system problem causing oil to be burned. This O ring missing allowed engine vacuum to suck oil straight into the intake system to be burned in the cylinders.

This is something seen many times, usually when changing the upper intake plenum. People forget to install both PCV O rings. This vacuum problem would also cause an EGR code. Either because of the vacuum problem, or oil has plugged up the EGR tube.


Question:
Dash light went out and tail lights went out at same time on my Chevy Impala. I have brake lights and turn signals. I can't find a fuse for either. Any Suggestions? I wonder, but have done nothing about it, but what the photo cell on the dash has gone bad. I can't find a way to turn off the DLR or parade dimming. Any suggestions?

Answwer:
If referring to the back-lighting of the dash, these and the taillights are two different circuits. Although they have a few things in common.

First check the fuse labeled 'Rear Park Lamp' in the passenger side fuse block. This is behind the access panel on the side of the dash with the door open.

The 'park lp relay' feeds this fuse, and also the front park lamp fuse, so this does not seem to be the problem. The relay is controlled by the body control Module (BCM).

The dash backlighting is also controlled by the BCM, from an input from the headlamp switch dimmer. Also check the 'STR COL' fuse in the left side fuse block. As you can see, these are pretty complicated circuits. Check all fuses to play it safe. My experience.


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