August 2, 2022
![]()
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 Elgin, 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 Elgin, Illinois.
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 Tuffy Auto Service Center Elgin, we will make sure your PVC is replaced if needed.
Tuffy Auto Service Center Elgin
395 S. Randall Rd
Elgin, Illinois 60123
847-717-4682

March 22, 2026
You may have noticed sometimes on a hot and humid day, vapor will come out of your vehicle's vents when you have the air conditioning on. Is that something to be concerned about? Well, it depends. Sometimes that steam or vapor can be caused by water accumulating in the vent system after it has c... More

March 15, 2026
You may have heard someone say they just got the air filter replaced in their vehicle. But did you know your vehicle has two different major air filters and they both perform quite differentbut very importantduties? Todays vehicles have a cabin air filter, and an engine air filter. The engine a... More

March 8, 2026
Weve all noticed them at one time or another on the street: a car or truck that drives by and the deep roar from their exhaust system sounds like a drag racer on the line. But what happens when that rumble is coming from under YOUR vehicle? Well, it could be a sign your muffler needs attention. ... More