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Questions tagged [pcv-valve]

PCV is and acronym for Positive Crankcase Ventilation. It is part of a system that helps control air pollution by burning fumes that collect in the engine crankcase instead of venting them to the atmosphere.

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How to test what caused pressure to build in crankcase?

After an oil and filter change I took my Toyota Avensis 2006 Estate with 1ZZ-FE 1.8 liter petrol engine for a long distance ride. All of the sudden when riding at around 60-70mph I heard some bang and ...
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1 answer
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High crankcase pressure, no flow through PCV valve

I have a 2011 Acura RDX with 385000km on it. When I remove the oil filler cap with engine running, the air blowing out the filler hole is substantial. With engine running I unplugged the output side ...
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Suburban stumbles at idle, unknown tube spewing black liquid into air intake is suspected cause. Please advise?

I have a Chevrolet Suburban 2008 1500 with the 5.3L V8 engine. A tube that I believe to be the PCV hose is spewing black liquid into the air intake, and the engine is stumbling at idle. The liquid ...
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795 views

Why would an oil separator have a vent into the engine bay?

This is Alfa Romeo Giulietta installed oil separator. Disassembly shows the vent is guarded by a flat rubber circle pushed up by a spring. This rubber flab probably ensures the air only flows in. ...
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1 answer
281 views

Where is the PCV valve on my engine, and how can I check/change it?

I have a Chevrolet suburban 2008 1500 with a 5.8L V8 engine. Can you describe with pictures where the PCV valve is, and how to check and replace it? I suspect it to have failed. Some have said it’s on ...
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Auto transmission slow to engage drive

Auto transmission slow to engage drive and gets worse as the car warms up, after 15 minutes and almost refuses to engage drive at all. Reverse is ok though. If drive does engage it can change up ...
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1 answer
164 views

Should the PCV breather hose affect fuel trims?

Noticed that my long term fuel trims have dropped negative over the years and am wondering if something is up with the positive crankcase ventilation system. I am familiar with logging data so logged ...
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121 views

Blue smoke when starting cold after fixing the PCV valve

I’m trying to clean the PCV valve on my 2004 Toyota Corolla Altis when I discovered that it’s stuck closed because someone intentionally covered it with plastic rubber. I bought the car 2nd hand about ...
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1 answer
3k views

PCV Valve for Ford Focus 2009

I have a Ford Focus 2009 SE 4-Door (2nd generation) at 180 000 km. The maintenance schedule said I need to replace the PCV Valve. I went to the Ford dealer to buy the part but they told me my model ...
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2 answers
8k views

Smoke coming out of oil fill port

I've been reading up on this smoking oil dipstick tube/oil port for Volvos and they all seem to stem around a clogged PCV system as being the root cause. We're looking at a 2005 Volvo S80 5cyl 2.5L ...
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1 answer
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Is it possible to create a PCV hose with a custom shape?

I have a car with a PCV hose that is hard to find. Is there anyway I could reshape a similar diameter/length hose to make it fit? If I can't do it myself, could a mechanic do it?
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Typical crankcase pressure range for a 2.0T gasoline engine

I'm putting together a oil "catch can" system for my Hyundai 2.0T (Theta II) engine. Instead of using a catch can, I plan to use a pneumatic coalescing filter, like a Parker-Watts F501/F507 ...
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8 answers
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Is the vent from the pcv valve back into the air intake really needed?

After working on my car, I didn't bother to reattached the line from the pcv valve into the air intake before testing the motor. It ran normally. This made me question whether I need to even return it ...
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Smoking XC90 after PCV box replacement

I have a 2003 Volvo XC90 2.9L T6 AWD and for the most part, it’s been great. Over the past year or so I’ve had an issue with it randomly stalling at slow speeds which was progressively getting more ...
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PCV Valve hose question

What is a PCV Valve Hose made of? Can any rubber hose replace it? Like the rubber hoses used for gas lines in lawnmowers? Does it need to be made of some type of plastic? From what I understand, the ...
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1 answer
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Positive crankcase pressure in Astra H 2008 Z14XEP

I've been suspecting an issue with the PCV system in my Opel Astra H 2008 with a Z14XEP petrol engine. It blew both the oil pressure switch and (probably, have yet to investigate) the front crankcase ...
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3 answers
23k views

Oil in air intake: is this a faulty breather valve or by design?

I noticed the other day that a component (breather valve) was not fitted properly (the clip that held the valve cover breather in place was sitting between the O-ring and the lip, instead of fastening ...
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3 answers
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Does checking for air coming from the oil fill hole tell you that the engine is bad?

This video suggests removing the oil cap when the engine is running and checking for the amount of air that is coming from the oil fill hole. (They call this air "blow-by".) He says that if the air is ...
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2 answers
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Replacement PCV valve unavailable. Will any other do?

1979 Leyland Sherpa 230 petrol 1.7l with "O series" engine I have an "oil separator" (or oil catch can) attached to the side of my engine. From there it goes through a hose to the ported vacuum by ...
4 votes
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Toyota auris 2010 stalls when you remove oil cap while engine is idling

I was inspecting a used Toyota Auris (2009-2010). I turned the engine on and with the car idling I removed the oil cap from the engine. The car stalled within seconds and the engine almost shut down. ...
2 votes
0 answers
913 views

Tracking Down Excess Crankcase Pressure

So a problem I've been putting off dealing with for a long time is the excess crankcase pressure in my 99 Nissan Almera 1.6L. You can see here in the air box the results of this excess pressure: ...
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988 views

CEL after cleaning throttle body and replacing PCV valve - false negative?

Today I performed the following maintenance on my 2007 Subaru Outback 2.5i wagon: Replace air filter Clean throttle body Replace PCV valve Replace all PCV pipes Replace throttle body gasket The PCV ...
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465 views

PCV valve location

I'm looking for the PCV valve in my Peugeot 106 1.1 TU1JP (HFX) year 2000. I can't find it, the closest thing I found is a hose going from the cam cover to the air filter, the connector on the air ...
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1 answer
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2002 Toyota RAV4 Stripped PCV Valve Threads on Valve Cover

Stripped PCV valve threads on valve cover while removing old PCV valve; however, new PCV valve wiggles but does not fall out, even with tugging. Also, short and long term fuel trims at idle have not ...
2 votes
2 answers
4k views

What is this PCV hose connector near the throttle body?

I have a 1994 Buick Century 3.1L V6 I know that the PCV hoses in my car need some TLC; that fact is readily apparent because someone has liberally applied zip ties to some of them to keep them in ...
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'04 Seat Cordoba makes a rythmic pulsating sound

I got a '04 1.4 Seat Cordoba here (340k on the odo!) and it makes a rythmic pulsating sound. The sound occurs under all conditions; warm/cold engine, low/high engine load etc. At first I thought I ...
5 votes
1 answer
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Planning to fit an oil catch can into my car. Any problems with this setup?

I own a 2007 Ford Fiesta ST150, I have modified it a little, one of the mods is a cold air intake. I want to install an oil catch can setup, but as the PCV vent is behind the intake manifold and ...
5 votes
1 answer
3k views

2001 Mercury Sable -- Rough Idle/High RPM and Transmission Leaks

I have a 2001 Mercury Sable (24V DOHC V6) that has been having problems with its vacuum system. I live in Florida where the average temperature lately has been in the 80s. I've been experiencing a ...
3 votes
1 answer
6k views

In the PCV system, is an "Oil Trap" the same thing as a "Breather Box"?

I've seen images of something labeled as an oil trap that looks like a box shaped part. In another context, I hear people talking about breather boxes. It sounds like they're talking about the same ...
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high oil consumption and oil pressure, possible PCV system malfunction

I have a 1993 C1500 4.3L manual transmission. My oil pressure has been reading very high (fluctuates, but generally goes beyond the upper range of the gauge). I had the truck in the shop and the ...
3 votes
1 answer
6k views

Where is the PCV valve on my 2011 Ford Focus SES (Duratec engine)?

I have a 2011 Ford Focus SES with a 2.0 liter I4 Duratec PZEV (California edition) engine. My repair manual suggests replacing the PCV valve every 60k miles (I am currently at 75k). I am trying to ...
1 vote
1 answer
815 views

Is this PCV hose broken?

I asked a question earlier about a P0171 MIL in my 2007 toyota corolla. The question is here: Diagnosing P0171 2007 Toyota Corolla I only have a OBD2 reader, I just bought a scanner, which should come ...
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1 answer
709 views

oil spots on Air Filter

I have Matiz 1.0 with 122K Km on the meter. Today i noticed oil on air filter after inspection i found this might be coming from PCV hose(green highlighted one) and then inspected the PCV valve. ...
3 votes
1 answer
881 views

Testing PCV: Constanct Suction or Pulsing Suction

I tested my PCV by taking off the oil fill cap and placing a piece of paper over it. I observed a pulsating suction and not a constant suction. Is that normal? If it's normal should I clean the PCV ...
4 votes
1 answer
753 views

How to diagnose a vacuum hose leak or pcv pump problem

I have a old 1993 Mitsubishi Triton MJ which is having a bit of an issue at the moment with acceleration. With the initial acceleration such as moving away from traffic lights the engine will often ...
2 votes
1 answer
88 views

Follow Maintenance Manual or Service technician recommendations?

We have a 2006 Highlander. Whenever we take it for regular servicing, the service technician recommends some items not specified in the maintenance manual. We told him that and he said it is common ...
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Is there such a thing as a throttling valve that can operate with oil as the working fluid?

I'm searching for a throttling valve that uses oil in order to convert pressure into thermal energy that can then be extracted via a cooler. Is there such a thing as a oil throttling valve? It would ...
2 votes
1 answer
164 views

No check valve on valve cover

On a 2004 Neon RT 2.0 SOHC we had an issue with one of the rockers. When we took the valve cover off to replace the rocker, we noticed that there was no baffle in the valve cover. There were large ...