Skip the auto shop - Our mechanics make house calls

Q: PCV valve or hose failure?

asked by on

I have oil built up in my intake system and filter. I read where it said it may be the pcv valve but the valve rattles and seems OK. The hose coming from that valve to the top of my intake manifold is bent and seems to be almost pinched shut. Is there a way I can fix this to where it will stay open? Do you have any suggestions or tips I could try? I get poor mpg, sometimes when I start the van it will idle low and sometimes bog up and down and then die. Sometimes it'll bog up and down and then go to just a little under 1000 rpm. I can feel it lose alot of lower going up a hill or when gaining speed.
My car has an automatic transmission.

A: Hello. The PCV valve regulates the flow of ...

Hello. The PCV valve regulates the flow of crankcase fumes to the engine to be burned when there is greater pressure in the crankcase than there is in the engine intake - which is most of the time. If the engine has worn piston rings, there is more combustion gases (also known as "blow by") and pressure in the crankcase, so more oil fumes are vented to the engine, gunking up the throttle body, idle air control valve, mass air flow sensor, etc.

This is somewhat normal over the life of the engine, but also indicates an engine wear condition. Perhaps the hose you mention is a generic hose bent from a straight piece, and instead should be a molded hose that is pre-bent to the correct shape, and has good flow? Check that out. I would recommend having a rough idle inspection completed by a mobile, professional mechanic, such as one from YourMechanic. They will be able to come to your location, diagnose this problem, give you an accurate assessment of damage and cost for repairs.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Bad thermostat causing overheating

The vehicle will need to be pressure tested to see if the intake and/or head gaskets are leaking coolant. The thermostat and housing should be checked for leaks. If these checks are okay, then the thermostat should be checked for...

Q: Brake light circuit warning light illuminated - 1998 BMW 323is

Sometimes, there is just enough corrosion on the end of the bulb to trigger this warning despite the bulbs illuminating correctly. Using some emory cloth or very fine sandpaper, rub the contact end of each of the brake bulbs to...

Q: PCV valve hose collapses

I am guessing your PCV collapsed because it is old and weak. This will cause your PCV to collapse while it is in vacuum. I would recommend going to your local auto parts store and picking up a reinforced braided...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...