PCV Valve Replacement for oil consumption?

[DeeInSeatown]

Having oil consumption issues now. Unsurprisingly, changing oil brand didn't help the issue (LiquiMoly to VW/Audi -Castrol?).

Now looking at the PVC valve as I'd read that a failing valve can lead to oil consumption. FCP Euro has VW Audi brand or the OEM brand Vaico at a much lower price. Anyone have experience, good or bad, with the Vaico as a replacement part here?

Also, I think replacing this valve is a little bit of hopeful black boxing. I don't think it's going to fix the problem either, but I'd like to rule this out before coming to worse and more expensive conclusions. Car is a 2014, so at time of purchase thought it was manufactured after the oil problems on the earlier cars were fixed. Apparently not.

[Lanorg]

PCV valves are notorious for oil consumption issues on various engines.

You can pressure test the PCV system to see how it responds, or replace your pancake valve and 1-way ball-valve in a guess attempt, as you mentioned. Sometimes they leak and allow pressurization of the crank case to ultimately blow oil into the pcv system to the intake.

I recently had an oil consumption issue, and after replacing my pcv valves i still had the issue. However, removing the connection to the intake and plugging the intake port stopped the consumption, so it was indeed PCV induced. Further investigation revealed a clogged catch can. After cleaning it and reconnecting the pcv the operation returned to normal.

Consider contacting blackstone oil analysis and requesting a sample bottle be sent to you. You can have them perform analysis on the oil to identify contaminants that would point to something like cam, bearing, or ring wear among others. It's also a great way to identify how good the oil you're using is for your application. I was running fuchs 5w40 but after testing rotella 5w40, it was identified to have slightly higher zinc and phosphorus levels, which are "good" for turbo applications. So I run that.

[Theiceman]

It's your rings.
But for the couple hundred bucks try the PCV. Vaico is junk. Go OEM ( hengst)


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[RPMtech147]

What kind of consumption are you getting? (Liters of oil to miles). As far as I know, the later cars had the redesigned rings that don't have the issue. I would just go ahead and replace the PCV anyway as they die around 100,000 or earlier.

[Theiceman]

What kind of consumption are you getting? (Liters of oil to miles). As far as I know, the later cars had the redesigned rings that don't have the issue. I would just go ahead and replace the PCV anyway as they die around 100,000 or earlier.

No they do not.
I had to rebuild my 2014 for oil consumption and it had old ring design.
Good question about how much oil though.
I was 1 litre for 200 miles

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[DeeInSeatown]

I'm at about 1500 miles from max to min on the MMI oil level meter. Don't recall how much oil that is. Car has about 73k miles. Other odd symptoms are a weird hiccup on startup. Last time I ran vcds scan, I also got two faults p053f (fuel pressure too low during cold start) and P0088 (fuel rail/system pressure too high), leading to a timing chain tensioner and timing chain tension adaption rabbit hole

One thing that concerns me is if the oil issue consumption may be a bit of a self-own. Oil consumption went up after changing spark plugs. I wonder if the spark plug holes had just a bit of crud that got down into the bore when plugs were out, leading to a bit of scouring. That leads me to the IceMan conclusion, a rehab I have no interest in tackling.

I like the idea about the oil analysis. I've always heard of that but never used it. They're able to id failing parts as certain components in the engine have higher levels of certain metals? Is the high zinc something unique about Rotella, or something unique about how that oil works with your car? If I tried replacing parts of the PCV valve, I'm not seeing a ready source for individual components on either ECS or FCP Euro.

Also, multiple PCV valves? Thought there was just the one atop the head?

[Theiceman]

A litre per 1500 miles is not attrocious. But you are on your way..
Even though none of us agree. Audi would say it's in spec I'm sure.
I don't think it's your crud in the cylinder.
Did you change plug types ? Or maybe do an oil change at the same time to a different viscosity or brand ?

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[DeeInSeatown]

A litre per 1500 miles is not attrocious. But you are on your way..
Even though none of us agree. Audi would say it's in spec I'm sure.
I don't think it's your crud in the cylinder.
Did you change plug types ? Or maybe do an oil change at the same time to a different viscosity or brand ?

It did coincide with an oil/filter change, but that was like for like. Same brand and weight of oil went in as came out. The car had used a bit of oil between changes before that service, but it was not much. Probably less than a quarter down from full between changes prior to this. Knowing the history of oil consumption in these cars, the quick change in trend is what I find alarming. I installed Bosch FR6KPP332SKT, don't remember if that's what I pulled out. I believe I left the gap a little wider on the new plugs.

And I agree that while Audi would likely say that's "in spec" I disagree that rate of oil use is acceptable at this mileage. What frustrates me is in all of the Audis I've owned, I'm yet to have one that didn't consume oil. B5 A4, that one is up to about a quart/500. Type 44, 91 200TQ same thing there 1qt/500 miles with occasionally horrendous oil clouds after sitting in traffic.

[morris39]

Having oil consumption issues now. Unsurprisingly, changing oil brand didn't help the issue (LiquiMoly to VW/Audi -Castrol?).

Now looking at the PVC valve as I'd read that a failing valve can lead to oil consumption. FCP Euro has VW Audi brand or the OEM brand Vaico at a much lower price. Anyone have experience, good or bad, with the Vaico as a replacement part here?

Also, I think replacing this valve is a little bit of hopeful black boxing. I don't think it's going to fix the problem either, but I'd like to rule this out before coming to worse and more expensive conclusions. Car is a 2014, so at time of purchase thought it was manufactured after the oil problems on the earlier cars were fixed. Apparently not.

Would you mind providing a little bit of detail, specifically your oil change history and your service conditions eg city/HW? Not helpful for you I know, but maybe for others.
As for the PCV function there is a simple vacuum gage test of crankcase pressure which is useful but you need a baseline measurement to be reliable.

[DeeInSeatown]

Would you mind providing a little bit of detail, specifically your oil change history and your service conditions eg city/HW? Not helpful for you I know, but maybe for others.
As for the PCV function there is a simple vacuum gage test of crankcase pressure which is useful but you need a baseline measurement to be reliable.

I'd have to get my records for better info, but off the top of my head bought the car in 2017. Was a lease return with 55k or so, maintained by Audi of Tacoma at what appeared to be standard factory intervals. Once I bought it, just followed the standard Audi maintenance schedule, replacing a couple of things that I didn't have record on (air filters, cabin filter, plugs).

Oil changes were essentially annual since I don't drive much, mostly took the bus to work until COVID. Drive cycle is probably 50-75% city with annual oil change at around at 5000-7000 miles? Since I bought the car, used LiquiMoly full synthetic oil change kit from FCP (5W40 LiquiMly Leichtlauf and Mann filter). Last change I subbed in the VW/Audi full synthetic to see if it changed the consumption. No apparent effect.

No baseline on original crankcase pressure, and also don't have a vacuum gauge at my disposal for the test.

[morris39]

I'd have to get my records for better info, but off the top of my head bought the car in 2017. Was a lease return with 55k or so, maintained by Audi of Tacoma at what appeared to be standard factory intervals. Once I bought it, just followed the standard Audi maintenance schedule, replacing a couple of things that I didn't have record on (air filters, cabin filter, plugs).

Oil changes were essentially annual since I don't drive much, mostly took the bus to work until COVID. Drive cycle is probably 50-75% city with annual oil change at around at 5000-7000 miles? Since I bought the car, used LiquiMoly full synthetic oil change kit from FCP (5W40 LiquiMly Leichtlauf and Mann filter). Last change I subbed in the VW/Audi full synthetic to see if it changed the consumption. No apparent effect.

No baseline on original crankcase pressure, and also don't have a vacuum gauge at my disposal for the test.

Thanks for your reply. A rough summary then is standard Audi oil change intervals; low mostly city mileage; short trips?

[DeeInSeatown]

Thanks for your reply. A rough summary then is standard Audi oil change intervals; low mostly city mileage; short trips?

I think that’s a fair summation, with oil changes more dictated by time than mileage, and predominately short trips.

[morris39]

I think that’s a fair summation, with oil changes more dictated by time than mileage, and predominately short trips.

Fertile ground for bias confirmation then. But who cares about other peoples biases?

[Kolbenringe]

Having oil consumption issues now. Unsurprisingly, changing oil brand didn't help the issue (LiquiMoly to VW/Audi -Castrol?).

Now looking at the PVC valve as I'd read that a failing valve can lead to oil consumption. FCP Euro has VW Audi brand or the OEM brand Vaico at a much lower price. Anyone have experience, good or bad, with the Vaico as a replacement part here?

Also, I think replacing this valve is a little bit of hopeful black boxing. I don't think it's going to fix the problem either, but I'd like to rule this out before coming to worse and more expensive conclusions. Car is a 2014, so at time of purchase thought it was manufactured after the oil problems on the earlier cars were fixed. Apparently not.

Check the archive on posts from me about this subject. I actually changed my oil separator and it worked until it didn't anymore. First, my car had a stage 1 oil consumption fix in 2013-2014, which included the white top oil separator and new front crank seal (which I later saw was installed crooked and was leaking). Fast forward- I bought a black top in 2018, not knowing the difference and running the VIN. My consumption was really high and a valve in it failed anyhow and consumption rose. I put a new white top on and it worked and for about a year was ok until it wasn't. I put on a vaico this time, but it only marginally helped. I had the engine rebuilt and the Vaico is still on, no issues.

Make sure you look for my posts and the supporting posts on the white top vs. black top oil separators. It doesn't always go by VIN and what the car was originally built with.

[Theiceman]

I think that’s a fair summation, with oil changes more dictated by time than mileage, and predominately short trips.

some good info here , and i'd be careful whos posts you listen too, there are some conspiracy theorists on here with very little technical knowledge, so i would vet your sources well. I do have a thread indicating nominal vacuum at idle that you can just check at the oil dipstick port, but im not sure it will tell you the whole story.

https://www.audizine.com/forum/showt...ghlight=vacuum

Bottom line is you already have a white top , stick with a white top , dont get distracted by BS.