Troy Drivers: Is It Time to Replace Your PCV Valve?
August 30, 2020
![]()
The crankcase is the lower part of the engine where the crankshaft is housed and where the engine oil lives. The crankshaft is connected to the pistons that power the engine.
When you are diving around Troy, fuel is burned in your vehicle engine, it pushes the pistons down and the crankshaft rotates and sends power to the transmission. Some of the explosive gases from combustion squeeze past the pistons and down into the crankcase.
Now this gas is about 70% unburned fuel. If it were allowed to remain in the crankcase, it would contaminate the oil and quickly turn it to sludge. Sludge is like Vaseline and clogs passages in the engine, leading to damage.
Also, the pressure build up would blow out seals and gaskets. So in the old days, there was just a hose that vented the crankcase out into the air. Obviously, not good for our air quality in Troy, Michigan.
Enter the PCV valve. It's a small, one-way valve that lets out the gases from the crankcase and routes them back into the air intake system where they are re-burned in the engine. Fresh air comes into the crankcase through a breather tube. This makes for good circulation in the crankcase. And that gets the air out. As you can imagine, however, the valve gets gummed up over time.
Your vehicle manufacturer usually recommends they be changed somewhere between 20,000 to 50,000 miles/30,000 to 80,000 kilometers. Unfortunately, PCV valve replacement is left out of some vehicle owner's manuals, but your friendly service advisor at Auto Lab Troy, we will make sure your PVC is replaced if needed.
Auto Lab Troy
2790 West Maple Rd.
Troy, Michigan 48084
(248) 643-7690
Need Service?
More articles from Auto Lab Troy

Don?t Be Hosed (Radiator Hose Replacement)
January 18, 2026
If you are like most drivers, you dont worry too much about what shape your radiator hoses are in. But they are a vital part of your coolant system, helping carry engine coolant from the hot engine to where it is cooled off in the radiator. When the cooling system has a problem, you will likel... More

Smooth Operator (Shock Absorbers)
January 11, 2026
When you are comfortably headed down the road, you may not realize how many of the imperfections in the driving surface are being smoothed out, so you hardly feel most of them. You can thank your shock absorbers for a lot of that comfort, and its important to make sure you keep your shocks in go... More

What?s That Yellow Squiggly Line Anyway? (What Warning Lights Mean)
January 4, 2026
You may have noticed when you start your vehicle, youll see several symbols light up on the dash. Theyre different colors and shapes, and sometimes its hard to figure out what each of those symbols mean. They are warning lights and symbolize something in your vehicle is sending you a message. I... More
