I am getting a bit of an annoying vibration at idle after driving. Despite this, the car idles great, 700 RPM, no fluctuation.
Recently, the car had a bit of a rough idle at start. The rough idle happened only a couple of times, not long after I put some new clamps on hoses. Also after replacing the clamps I notice the car has a bit more power, so I think I may have had a pressure leak.
I noticed a bit of oil seepage coming from the crankcase-to-throttle body hose, so I assume the TB and IACV might be getting dirty. Which brings me to my question...
Can I clean the IACV on this car without damaging it? Maybe using MAF sensor cleaner? I will also be changing the fuel filter and cleaning the cam sensors.
Clean IACV on 3.5L?
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atraudes
- Posts: 1106
- Joined: Thu Jan 10, 2013 7:46 pm
- Car: 2001.5 Infiniti QX4 4WD
- Location: Sammamish, WA
Re: Clean IACV on 3.5L?
I'd recommend throttle body cleaner since they're sure to have designed it to be safe with the IACV since it's part of the throttle body. The MAF cleaner is probably a safe bet too. I've heard a number of people here say they cleaned it without problem, so I'd go for it.
The throttle body itself doesn't have any crankcase hoses attached to it though. It has two small coolant hoses going to it, but that's it. There is a crankcase hose nearby on the intake manifold.
You could also try the idle relearn procedure to see if that smooths things out at all. 700's within spec, but it's worth a try.
More food for thought: if you haven't replaced the IACV with a new unit yet, I'd highly recommend it. They're known to be ticking time bombs ($$$) on this engine
The throttle body itself doesn't have any crankcase hoses attached to it though. It has two small coolant hoses going to it, but that's it. There is a crankcase hose nearby on the intake manifold.
You could also try the idle relearn procedure to see if that smooths things out at all. 700's within spec, but it's worth a try.
More food for thought: if you haven't replaced the IACV with a new unit yet, I'd highly recommend it. They're known to be ticking time bombs ($$$) on this engine
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rgk
- Posts: 588
- Joined: Tue Dec 23, 2014 4:48 am
- Car: 02 Pathfinder LE 3.5 auto 4x4
- Location: Indiana Dunes National Park
Re: Clean IACV on 3.5L?
Yeah, I was wondering if someone would recommend replacing it.
I didn't think about the relearn, good call.
I'm talking about the hose that goes to the intake tube. I'm concerned that oil might be gunking up the TPS and maybe the IACV. Warranted? It's clearly getting sucked into the intake. A catch can has been recommended, but I haven't done it yet.
I think that replacing the fuel filter helped a little. The vibration gets worse as temps drop.
I didn't think about the relearn, good call.
I'm talking about the hose that goes to the intake tube. I'm concerned that oil might be gunking up the TPS and maybe the IACV. Warranted? It's clearly getting sucked into the intake. A catch can has been recommended, but I haven't done it yet.
I think that replacing the fuel filter helped a little. The vibration gets worse as temps drop.
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atraudes
- Posts: 1106
- Joined: Thu Jan 10, 2013 7:46 pm
- Car: 2001.5 Infiniti QX4 4WD
- Location: Sammamish, WA
Re: Clean IACV on 3.5L?
Ohh gotcha. For some reason I thought that tube went to the brake booster. Must've gotten the two mixed up.
Have you changed your PCV valve yet? I believe the the way the PCV system is plumbed is air gets pulled into the crankcase via that tube on the intake duct, through a hose to the other valve cover, through the PCV valve and into the intake manifold. The intake manifold side will always have a higher vacuum meaning any oil ingestion should happen there. My point is I don't think that particular hose should be leaking oil at all. A plugged PCV valve could explain that though.
That's not to say you're wrong though; if it has oil on it, it should be cleaned
Have you changed your PCV valve yet? I believe the the way the PCV system is plumbed is air gets pulled into the crankcase via that tube on the intake duct, through a hose to the other valve cover, through the PCV valve and into the intake manifold. The intake manifold side will always have a higher vacuum meaning any oil ingestion should happen there. My point is I don't think that particular hose should be leaking oil at all. A plugged PCV valve could explain that though.
That's not to say you're wrong though; if it has oil on it, it should be cleaned
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rgk
- Posts: 588
- Joined: Tue Dec 23, 2014 4:48 am
- Car: 02 Pathfinder LE 3.5 auto 4x4
- Location: Indiana Dunes National Park
Re: Clean IACV on 3.5L?
I think I found my answer. I already know I have compression leaks, and this page explains how that contributes to excessive blowby: http://www.bobistheoilguy.com/blowby.html
Does anyone have any recommendations on what can be done to slow down wear? The page mentions Moly, but AFAIK, that is a rebuilding grease.
And yes, I have a new PCV valve, but I think I may be experiencing what Haynes calls 'abnormal conditions,' i.e. worn piston rings or scored cylinders, probably due to the power valve fiasco.
Does anyone have any recommendations on what can be done to slow down wear? The page mentions Moly, but AFAIK, that is a rebuilding grease.
And yes, I have a new PCV valve, but I think I may be experiencing what Haynes calls 'abnormal conditions,' i.e. worn piston rings or scored cylinders, probably due to the power valve fiasco.