The Valve That Can Cause Major Engine Troubles - How to Avoid Engine Sludge

In this video I am going to explain to you a valve that when it goes bad, it can cause hard to diagnose performance issues because the symptoms are very similar to a lot of other failure but also if not fixed it can lead to major engine failure as well. I am going to talk about the symptoms it may cause an engine like smoking out the tail pipe, excessive oil consumption, a rough idle, constant oil leaks, oil contamination etc . But I will also share with you how you can quickly and easily diagnose and fix the problem as well.

Disclaimer:
Due to factors beyond the control of Ratchets and Wrenches, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. Ratchets and Wrenches assumes no liability for any property or personal damage that may arise from doing a repair on your vehicle after watching any of my repair video's. Due to factors beyond the control of Ratchets and Wrenches, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Again Any injury, damage or loss that may result from improper use of tools, equipment, or the information contained in this video is the sole responsibility of the user and not Ratchets and Wrenches.

[mike]

Cheap, and easy to change. People don't talk about it as a maintenance item enough. 👍

[Rajiihammr]

This video may have helped me solve my '96 Olds 88 rough idle problem. I replaced plugs, wires, cleaned fuel injectors to no avail. But after viewing this video I hunted down the valve (it's hidden under the MAP sensor) and replaced it. The valve did not move freely. Total cost $3.21! Idle is better and I'm hoping oil consumption will improve too. Thanks!

[lewisbeshers]

One of the first thing a young car guy learns about is how a bad pcv can muck things up and cause problems that aren't always easily discernible. Thank you for the full and clear explanation. Always glad to learn new things from your channel.

[TJHutchExotics]

Thank you for the video and great explanation. My husbands truck hasn’t been sounding right on the highway. I drove it yesterday and the “low oil pressure” light came on and then went right back off. I decided to check the oil- ZERO oil on the dipstick. Did some research and tested the PCV valve, zero suction. Waiting on hubby to bring me the part- I’m just hoping no damage occurred. I had no previous knowledge that something so simple could prevent major issues

[kaeosfactory]

Did not know about the dipstick popping out. Mines used to be doing that. Had a major oil leak also. I definitely learned something new just now

[georgehogle]

I very much enjoyed your video on the PCV valve; it explained how the valve functions in regular everyday terms without getting caught up in the jargon. Nice, simple and it made sense to someone who is not a motorhead. Well done!

[spelunkerd]

Gotta love your engine videos like this one, there's nothing better than your clear thinking explanations.

[kngez]

Replaced on 70s 302 Ford pickup. Fram. Ran lean backfired up carb. Always use factory part. Genuine Ford valve fixed.

[redgadget]

Thank you so much for the explanation of the PCV valve, I usually do all of my own work but my wife’s car is still under warranty so I let a garage (warranty approved garage) work on the car idling bad at stop and stalling a little while going down the road. They told me it was the left side valve cover gasket letting oil into the intake. I had to see if this was correct. Through your video you explained how this can happen. They should have just told me the PCV valve though. I really like your page and very detailed for us DIY’s out here.

[splash]

Ive been lucky enough on my vehicles over the years, the PCV valves are easily accessible. When i do my oil changes, i remove the valve and spray a little carb cleaner in there to flush any residue out. Havent had an issue with one yet...
Great explanation of the PCV system.

[CLardPercussion]

Just found your channel. My only complaint is that I didn't find it sooner! Rock on man!!

[UFOGHOSTHUNTER]

Great Video as always!! The only thing is try not to use gloves when checking the vacuum on the pcv. I had a small piece tear off and suck through my pcv valve. The force was strong in my truck!!

[jorgeperez]

You're a car genius and very good at teaching and explaining how cars work!!! I really appreciate you. Keep up the good work!👍

[shanetasker]

These videos are great for solving simple problems that otherwise would be by mechanic and automotive shops that would replace the $25-50 part but charge you for a pile of "OTHER" works they didn't really do.

[txmoney]

Great explanation on PCV valves.
At 120, 300 miles I replaced the water pump (weephole leak) and drive belt on my 2018 Civic EXT. Since Honda service were already working on that I had them replace the PCV valve as preventative maintenance. Aside from an earlier AC Condenser replacement (fully covered under Honda extended warranty), the water pump, drive belt, coolant flush was the only major work on my four-year old Civic (Total cost: $1, 045.00). Currently averaging 34.1 mpg. Great car.

[boblamb]

I rebuilt my first engine by myself top to bottom in 1969 as a 14 year old. it was a 1954 272 Y-block Ford. Worked as a heavy equipment mechanic for over 31 years for a local municipality 9 years as a shop supervisor. I learned hands on rebuilding and repairing things not replacing them from old timer's who knew more than I could ever fathom learning but they taught me all they could including welding, machining and fabricating. I was a good student and a fast learner. Attended an automotive tech school for four years. Could have been a teacher. Was NAISE certified in every phase. None of my mentor's ever gave much thought to the PCV positive crankcase ventilation system even on engines that were not taken care of. In my 40 plus year career I never found a stuck or malfunctioning PCV valve or suspected one of causing a major engine or component failure. Yes compression can sneak by the rings on older engines as well as new one's and cause some blow by and slight pressurization of the crankcase however in order for that much pressurization to occur it would blow out a seal or a gasket first. I do know if a PCV valve is stuck in the open position it can suck in engine oil and burn it along with crankcase vapors through the carb base however all factory valve covers have a baffle that covers the small place where the PCV valve lives protecting it from engine oil slung up from the rocker arms. So in theory even one stuck open would not cause an excessive oil consumption issue. Aftermarket valve covers often lack that little protection for the PCV and an oil consumption issue could arise. Since a PCV has full manifold vacuum to it that can be a starting place to look for an engine performance problem such as a rough idle. No two mechanic's agree 100% 0n everything. Most agree to disagree.

[Mahigeer]

Nice tutorial. If I may add:
I was thought that the main reason for the spring operated valve inside the unit was to prevent flames from backfired carburetor to go back and ignite the air fuel mixture in the crankcase.

In old engines with carburetors, a backfire flame can travel through intake manifold through the hose back to the valve cover and down to the oil pan area. Thus, the name Positive Crankcase Ventilation valve. Otherwise a one-way valve.

Before PCV valves on engine, there was a draft tube that vented the unburn air and fuel mixture to the atmosphere. This produced smog.

With fuel injector systems on cars, there is very little if any chance of backfire. There is still a need to remove unburned air/fuel mixture from the crankcase.

A small spray of carb cleaner can go a long way to keep the valve working.

[fuyingbro]

I had an issue with a 01' Firebird. I was fixing everything on it trying to figure out the issue. Went as far as a doing a complete head gasket replacement. It wasn't until I was putting everything back together that I noticed how nasty the intake manifold was. Yep it was a damn 5 dollar pcv that was causing the biggest of the issues. That said it was good to do the complete head gasket replacement as it was 160k and looked like it was starting to go. I swear it gain back a few ponies as I also polished the valves and heads.

[CoconutWaterfalls]

This is great information! i have the very symptoms you mention, and its only a $10 fix- and requires no tools!!! I’m pulling no codes, but there’s gas smell in the oil, a new oil pan leak, and a new valve cover leak, and i feel like performance could improve slightly. THANK YOU! /2002 Lexus RX300

[hotchihuahua]

good explanation of the PCV and a very important part, this to reduce pressure inside your engine and burning the blow by for cleaner air.