Back to all

PCV Valve Replacement

August 22, 2022



Hello Homer Glen, 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. Homer Glen 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 Homer Glen 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 Homer Glen . Fortunately, PCV valve replacement is both quick and inexpensive at Tuffy Tire & Auto Service Homer Glen. 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 Homer Glen 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 Homer Glen at 708-301-8885.

Tuffy Tire & Auto Service Homer Glen
15743 S Bell Rd
Homer Glen, Illinois 60491
708-301-8885

More articles from Tuffy Homer Glen

The Light Nobody Wants to See (Check Engine Light)

April 28, 2024

You've probably had your Check Engine Light go on. Then it goes off and you figure, hey, whatever the problem was, it's gone now and I don't have to worry about it. Well, the problem may have gone away and it may not have. Your vehicle likely has one of these warning lights on the instrument pa... More

Losing Your Cool (Why is My Air Conditioning System Not Working?)

April 21, 2024

When you turn on the air conditioning in your vehicle, you expect cool air to come out of the vents. You depend on it, especially in hot weather, but it can also be important in humid weather when you need it to help defrost your windows and windshield. The air conditioning system has a lot of p... More

Snake in the Engine (Serpentine Belt)

April 14, 2024

There's a belt that snakes through your engine. It's even named for a snake, the serpentine belt. It'll bite you when it breaks, possibly leaving you stranded. So, it's good to know a little about this snake-like belt. In early engines, there were lots of belts. They were used to convert the r... More