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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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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4answers
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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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1answer
1k 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. For roughly a month now, ...
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1answer
395 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 ...
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1answer
305 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 ...
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1answer
76 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 ...
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1answer
44 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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1answer
72 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. ...
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1answer
69 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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1answer
54 views

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 ...