PCV valve or hose failure?

ANSWER : Hi there. The PCV valve is located on bank 1; the valve cover closest to the cabin. It is usually found under the intake plenum towards the passenger side of the vehicle. The hose will be attached; or loose. Please understand that a code retrieval and an internet search is not a proper diagnosis as there are several other possibilities that can cause the code to set. Some of the possible causes could be spark plugs, ignition coils, intake manifold leaks, intake plenum leaks, vacuum hose leaks, failing airflow meter, failing O2 sensors, exhaust manifold leaks, low fuel pressure, failing ECU, faulty wiring harness, failing injectors, etc… As you can see, the list of possibilities runs on and on. This is where the expertise and experience of a qualified technician with the proper diagnostic tools and procedures becomes invaluable. I strongly suggest having a qualified technician perform an inspection to avoid replacing unnecessary parts and determine the exact cause of the code. Your Mechanic has several available technicians that can assist you with a check engine light inspection.

ANSWER : The PCV on this engine has a lock tab and unscrews from the valve cover. The tab may break when you try and remove it so make sure you have the correct one before you try and remove the old one. It will have what looks like threads on the bottom of the valve and will screw into the valve cover with a half turn and locks in place. To remove it, lift and turn counter clockwise and pull out. It will have an O-ring to seal it on the valve cover. If you end up needing some help with this, consider YourMechanic, as a certified technician can come to you and assist you with servicing your PCV valve.

ANSWER : 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.

ANSWER : 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 hose. These have a solid structure that will not collapse under vacuum. They will also be able to cut and match the length of your existing hose. Also, make sure the hose is sealed on both ends to ensure that there are no leaks. If you are in doubtful about this repair, I would recommend enlisting the assistance of a qualified professional in order to guide you through proper replacement of the PCV valve hose.

ANSWER : Hello. In most case a PCV valve should not noticeably rattle, though that varies from engine to engine. If it appears to be rattling excessively that could signify that the PCV valve is not secured properly, that there is a vacuum leak, or that the internal spring is weak or broken, and that the valve needs to be replaced.. An excessively rattling PCV valve could cause an unstable idle, hesitation, and oil consumption. A code for the EVAP system will usually be a separate issue from that of the PCV valve. If the code came on after working on the PCV valve, I would carefully check to see if there are any vacuum hoses or emissions hardlines that run near the PCV valve to see if they may be damaged or broken. If not, it may be possible that the EVAP leak is elsewhere. I would recommend having a professional technician, such as one from YourMechanic, come to your location to determine the cause of the PCV valve rattling, and if it may be related to the trouble code.

ANSWER : Hey there. Worn piston rings create more crankcase fumes (i.e. the smoke you see coming out of breather tubes and orifices). This is called "blow-by". As long as the PCV valve stays clear, and the engine can handle the fume/clean air & fuel mix, then you should be fine.

This is a normal stage of wear as long as tailpipe blue smoke doesn’t become excessive or offensive. The rough running at a stop light may be an early indication of too much blow-by, although those 6 cylinders engines had trouble with rough idle/low speed because of the big differences in the distance between the carb and each cylinder (Cyl 1 & 6 distant, cyl 3 & 4 very close). Keep it tuned, and watch for slow degradation in low-speed running. If you notice this problem worsen or would like to have this checked, then have a qualified professional from YourMechanic come to your car’s location to inspect the smoking problem and follow through with repairs.

ANSWER : Hello, thank you for writing in. Correct, you want to place the hose clamp between the two raised lips. If the hose will willfully go over the second lip, that is fine. The goal is to have the hose beyond the first lip, and have that lip there to give the clamp something to hold the hose on with. The second lip is to give an area for the hose to recede down into so the hose clamp can get a good grip. The longer the hose stays in place, the more the hose will form to the area giving you a good seal.

ANSWER : Hi there. The hose that you are describing sounds like the heater core by-pass hose. If the hose is short and straight, then it would be the heater by-pass hose. The heater by-pass hose it to by-pass the heating system until the engine is hot. If you need further assistance with your coolant hoses, then seek out a professional, such as one from Your Mechanic, to help you.