Back to all

PCV Valve Replacement

April 2, 2020



Hello Novi, 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. Novi 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 Michigan 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 Novi 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 Sovel's Auto Service . Fortunately, PCV valve replacement is both quick and inexpensive at Sovel's Auto Service. 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 Novi 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 Sovel's Auto Service at 248-348-7337.

Sovel's Auto Service
41425 W. 10 Mile Rd.
Novi, Michigan 48375
248-348-7337

Need Service?

Request a Quote

More articles from Sovel's Auto Repair Novi

Avoiding Exhaustion (EGR Valve Replacement)

March 30, 2025

No, ERG isnt the sound a pirate makes. Its a part in your vehicle that recirculates exhaust gas to reduce certain gases and pollutants in the atmosphere. In fact, ERG stands for Exhaust Gas Recirculation. One gas our vehicles may make when they burn fuel is nitric oxide, which can play a big ro... More

Prepare Your Windshield for Winter (Wiper Blades and Fluid for Freezing Temperatures)

March 23, 2025

Winter and freezing temperatures present challenges for different parts of your vehicles. For example, winter tires give you better traction on snow. But some parts of your vehicle that may need special attention for winter are your windshield wipers. You may have found yourself in the middle o... More

Differential Essential (Differential Fluid Exchange)

March 16, 2025

What's the dif? To an automotive technician, it's the differential, a part of your vehicle that helps direct power from the engine to the wheels. The differential is a gearbox that enables the drive wheels to turn at different speeds (they do that when you turn). Inside the differential is a f... More