Back to all

PCV Valve Replacement

August 24, 2022



Hello Aurora, let's talk about your often-unnoticed but extremely important PCV valve. The energy from exploding fuel is what powers your engine. But some of the vapors from the explosions escape into the lower part of the engine, called the crankcase. The crankcase is where your engine oil hangs out. These gases are about 70% unburned fuel. If the gases were allowed to stay in the crankcase, they would quickly contaminate the oil and turn it to sludge. Aurora folks know that sludge is one of the biggest enemies of your engine, clogging it up and eventually leading to expensive failures. Also, the pressure buildup would cause seals and gaskets to blow out. Therefore, these gases need to be vented out.

Pre-1963, gasoline engines had a hose that let the  fumes vent out into the air. In 1963, the federal government required gas engines to have a special one-way valve installed to help reduce dangerous emissions. (Can you imagine how polluted our Illinois air would be if every car had been releasing those poisonous fumes for the last 50 years?) Diesel engines are not required to have these valves.

The positive crankcase ventilation (PCV) valve routes crankcase gases through a hose and back into the air intake system where they are re-burned in the engine. Fresh, clean air is brought into the crankcase through a breather tube. It's really a pretty simple system, but it does the job. The re-circulating air removes moisture and combustion waste from the crankcase, preventing sludge. This extends not only the life of your oil but the engine as well. The PCV relieves pressure in the crankcase, preventing  oil leaks.


Eventually, the PCV valve can get gummed up. Then it can't move enough air through the engine to keep it working properly for Aurora vehicles. If the PCV valve is sticking enough, you could have oil leaks, excess oil consumption and a fouled intake system. If you experience hesitation,  surging or an oil leak, it may be a sign of PCV valve problems. Your vehicle's owner's manual may give a recommendation for when the PCV valve should be replaced - usually between 20,000 mi/32,000 km and 50,000 mi/80,000 km. Unfortunately, some don't list a recommendation in the manual, so it can be easy to overlook.


Many PCV system problems can be diagnosed by our technicians at Tuffy Tire & Auto Service Aurora . Fortunately, PCV valve replacement is both quick and inexpensive at Tuffy Tire & Auto Service Aurora. Proper oil changes will greatly extend the life of the PCV valve. Skipping a few recommended oil changes can allow varnish and gum to build up in the valve, reducing its efficiency. So now when your Aurora service technician tells you its time to replace your PCV valve, you will know what he's talking about. If you have had your car for a while and this is the first you've ever heard of a PCV valve, ask your technician to check yours out or call Tuffy Tire & Auto Service Aurora at 630-898-6688.

Tuffy Tire & Auto Service Aurora
3190 N. Aurora Rd.
Aurora, Illinois 60502
630-898-6688

More articles from Tuffy Aurora

You Are the Fluid Detective! (Leaking Fluids)

February 1, 2026

When you see some liquid sitting underneath your vehicle, your mind starts churning. Is that normal? Is that something serious, or did I just spill my drink? Heres a quick list of what those fluids look, smell and feel like, as well as what they might be. No, we dont recommend you taste them to ... More

Full of Hot Air (Air Conditioning)

January 25, 2026

In warm weather, you want to be in a cool vehicle. When we're talking cool, we don't mean stylish or trendy, but cool as in not sweltering inside. And if your vehicle's air conditioner stops working correctly, it seems to always break at the worst timeduring a heat wave. Automotive air conditio... More

To Fix or Not To Fix (Tire Repair)

January 18, 2026

You know that sinking feeling when you realize one of your tires has a problem. It may be making an odd noise or behaving oddly when you're driving. You may hit a pothole or curb and one suddenly goes flat. Or you may head back to your vehicle and discover it has one tire deflated without a cl... More