pcv valve
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elwesso
- Posts: 30810
- Joined: Sun Feb 23, 2003 4:52 pm
- Car: 94 Infiniti Q45t 5 spd
2007 BMW M Coupe
2007 Infiniti G35 S 6MT - Location: Indiana
- Contact:
Take off the black plastic cladding on the front of the engine (just foreward of the plenum)..... Its right under there, and its sorta hooked onto the radiator filler cap... Youll see 3 hoses come together at this point..... The PCV valve is where you take off the hose going towards the firewall, and you just unscrew it!!!
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
If the PCV valve is dirty [gooey] inside, so are all the hoses.
Most people don't realize that up to 20% by volume of the conventional oil can evaporate [the lighter fractions]. This either gets burned [bad rings or valve stem seals] or passses thru the PVC system to the input of plenum [after the throttle body].
This oil vapor mixed with the carbon from EGR and tiny particles that get thru the air filter is where all the gooey/gunky stuff inside the plenum is created.
An interesting test would be to adapt a spare oil cap to measure the air pressure of the inside of engine under various conditions ....especially cruise and WOT.
Idle and cruise vacuum sucks the oil past the valve stem seals and positive pressure in the engine surround helps push the oil into the cylinder.
Most people don't realize that up to 20% by volume of the conventional oil can evaporate [the lighter fractions]. This either gets burned [bad rings or valve stem seals] or passses thru the PVC system to the input of plenum [after the throttle body].
This oil vapor mixed with the carbon from EGR and tiny particles that get thru the air filter is where all the gooey/gunky stuff inside the plenum is created.
An interesting test would be to adapt a spare oil cap to measure the air pressure of the inside of engine under various conditions ....especially cruise and WOT.
Idle and cruise vacuum sucks the oil past the valve stem seals and positive pressure in the engine surround helps push the oil into the cylinder.
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rover3l
- Posts: 514
- Joined: Sat Oct 11, 2003 3:22 am
- Car: 1998 Q45, 2000Q45 Anniversary, 1965 Rover 3L,
Thanks for the info. I will do this job today and check the hoses as Q45Tech suggests. Wes although I am a Brit I used to live for 4 years in Carmel Indiana and had a work colleague Dan Jessop who lived in Anderson. Then I got a move to Buffalo four years ago
I have checked out your web site and it is cool. Looks like we have similar tastes in cars as I was also very interested at one point in Cadillac Fleetwoods. Back in the UK I was always interested in cars that were a little different from the run of the mill. My ideal UK garage would have had the following cars in it
1. Vauxhall Viscount2. Rover 3l (got that one)3. Humber Imperial4. Vanden Plas 4literR
I have checked out your web site and it is cool. Looks like we have similar tastes in cars as I was also very interested at one point in Cadillac Fleetwoods. Back in the UK I was always interested in cars that were a little different from the run of the mill. My ideal UK garage would have had the following cars in it
1. Vauxhall Viscount2. Rover 3l (got that one)3. Humber Imperial4. Vanden Plas 4literR
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rover3l
- Posts: 514
- Joined: Sat Oct 11, 2003 3:22 am
- Car: 1998 Q45, 2000Q45 Anniversary, 1965 Rover 3L,
I replaced the PCV valve today and low an behold it was all cruddy and the pipe from it that runs towards the firewall had a one inch slit in it that was sucking air. Replace it an the idle is now nice and smooth at about 550 RPM, although it seems as if the acceleration of the vehicle is now not as strong. I will see how it goes over the next day or two
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elwesso
- Posts: 30810
- Joined: Sun Feb 23, 2003 4:52 pm
- Car: 94 Infiniti Q45t 5 spd
2007 BMW M Coupe
2007 Infiniti G35 S 6MT - Location: Indiana
- Contact:
Rover- NO WAY!! Small world!!
My PCV valve is very gooey, and thats all gonna be spick and span after my plenum/valve cover job...... I also spot checked a few hoses, and its got oily goo in them.......
Dennis-- If I do an engine flush and clean my valve covers, would it still be useless to switch over to synthetic????
My PCV valve is very gooey, and thats all gonna be spick and span after my plenum/valve cover job...... I also spot checked a few hoses, and its got oily goo in them.......
Dennis-- If I do an engine flush and clean my valve covers, would it still be useless to switch over to synthetic????
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elwesso
- Posts: 30810
- Joined: Sun Feb 23, 2003 4:52 pm
- Car: 94 Infiniti Q45t 5 spd
2007 BMW M Coupe
2007 Infiniti G35 S 6MT - Location: Indiana
- Contact:
<sorry for the thread hijack>
I wanna know about my varnish and sludge.... Ill try and describe it the best I can.... When I open the oil filler cap, theres black stuff fused in there, and if I get a flashlight, I can see what looks like the VVT assy (looks kinda like a read gear), and its got poo looking stuff on it......
I went car shopping today (looked at a 94 sts, :drooling ), and I looked in there, and I could see stuff really easy, and it was really clean...... Im starting to think you cant see to well into the valve covers on the Q......
I wanna know about my varnish and sludge.... Ill try and describe it the best I can.... When I open the oil filler cap, theres black stuff fused in there, and if I get a flashlight, I can see what looks like the VVT assy (looks kinda like a read gear), and its got poo looking stuff on it......
I went car shopping today (looked at a 94 sts, :drooling ), and I looked in there, and I could see stuff really easy, and it was really clean...... Im starting to think you cant see to well into the valve covers on the Q......