Should I replace PCV Box 2006 V70 NA

goldmandan · Post by **goldmandan** » 26 Jul 2019, 05:50

Good morning all,

My wife's 2006 V70 2.4 natural aspired she says has been running sluggishly for the last month, not a lot of pick up and gas mileage has gone down. I opened the oil cap while running but saw no smoke, i also did the balloon test on the dipstick tube and it didn't inflate the balloon. Wondering if it's worthwhile to even replace the PCV box behind the intake? What benefit will it do? Car has 156k miles on it. Wondering if simply cleaning the MAF and TB would be better?

Any thoughts
Dan

Georgeandkira · Post by **Georgeandkira** » 26 Jul 2019, 08:56

People who work on our cars say 10 years and ~100K is the service life of those boxes.
I believe there's a plastic reed valve of sorts in it which stiffens or breaks with age
The benefit is restoring its operation.

I got mine standing by for installation come cooler weather. I'm still under 100K but my '07's old enough. In my case I have no smoke either but the glove just sits there. I want to see it draw in.

Spraying the MAF with MAF cleaner (allow to dry without touching) and cleaning the TB if necessary is just good to do.
You may find, as I have, that the non-turbo engines don't dirty-up their TBs as turbocharged engines can.
At 156K an inspection is appropriate.

Post by **mrbrian200** » 26 Jul 2019, 09:46

It was my understanding that the oil trap/box on an '06 is an 'open' design: crankcase gasses enter and exit toward the top, oil droplets fall via gravity, collect and are returned to the oil pan via a port/hose exiting from the bottom of the box.

Now what I'm not sure about is whether the banjo bolt at the intake manifold on an '06 NA has the integrated check ball/valve. Which on turbo models can start sticking (either open or closed) and/or the small hose attached to it starts to plug all due to carbon deposit buildup at around this mileage. On older Volvos the NA engines did not have this check ball integrated into that banjo bolt. But I'm pretty sure I've caught people with newer (within the range of MY06) finding that the original banjo bolt does have that integrated check ball. This could be responsible for lower econ/sluggish performance if the ECU is programmed to account for this being closed off during certain conditions when it is actually sticking open or vice versa. If it were plugged/restricted/stuck closed I would expect it to fail the glove test. But on an NA I'm not sure.

Anyone who is expressly familiar with how the PCV 'operates' on MY06 NA can key in/correct me please.

Post by **oragex** » 26 Jul 2019, 10:28

The question is, do you look at keeping the car for a few more years - especially since now it's lacking power and mpg. Engine power and gas mileage are one of those issues difficult to fix. I can be many things, no necessarily the PCV. You need to pull the spark plugs, see how worn are and also see if they have black tip (soot, means poor combustion). Also replace the fuel filter if it's the external one. My non turbo had horrible gas mileage and poor power when I got it. I had to do a good list of things, now it's finally getting close to 12l/100km city (close to the normal rating), 6.5 highway, has decent power. Won't list here what I think were the issues because it may sound unusual and I'm not 100% sure. But can tell that I suspect there can be issues with poor engine cooling from coolant deposits (usually caused by mixing tap water or using the wrong coolant), and possibly clogged compression ring grooves caused by faulty PCV (resulting in poor compression). If you want to clean the MAF, you need the special cleaner

On the other side, at 150k miles and with no suction, the PCV needs replaced if keeping the car. If you work yourself, a few tips here and here Buy the genuine parts online (don't buy Uro)

goldmandan · Post by **goldmandan** » 26 Jul 2019, 12:30

someone told me to unplug the front o2 sensor and see if power increases. could be clogged catalytic converter? i thought if that was the problem a code would have set and the CEL would have come on. Will do the easy stuff first, MAF and TB cleaning and see if it helps. I'm still not convinced the PCV needs replacing. But I know, it's a 13 yr old car....... 156k miles.........

Post by **oragex** » 26 Jul 2019, 14:09

The PCV can still go for a while, it gets worse when you notice fumes out of the dipstick and some whistle that goes away when the dipstick is removed. Mostly worth replacing if looking to keep the car for another few years. On these non turbo parts are under $200 + 2-3h labor at a garage that knows Volvo cars (I wouldn't bring it to some random garage)

Clogged converter is not that common, not sure how to diagnose it but very clogged ones will glow red at night, especially after a spirited drive
MAF and tb are good first steps, along with the spark plugs - these can tell quite well what is going inside the cylinders, by their wear and tip color

Post by **- Pete -** » 26 Jul 2019, 22:41

oragex wrote: ↑26 Jul 2019, 10:28 Buy the genuine parts online (don't buy Uro)

Totally not trying to pick a fight, or pick on anyone here.
While I generally abide by the "only buy Genuine Volvo parts" mindset, there is a small list of non-genuine parts I've got that is slowly growing.

On this list is an alternative to a particularly expensive and quite small piece of rubber that Volvo sells for about $75, and is part of an entire PCV system replacement. I almost barfed when I was breaking down the components in their PCV kit on FCP when I realized this tiny rubber elbow hose ran that much. Anyhow, make up your own mind, but I refuse to pay that for a 2ish inch piece of rubber. They are $11 on Amazon for aftermarket good-quality parts. I compared the two in my hands, side by side (Volvo vs Uro) and they are the spittin' image of each other.

I recently did a PCV job on our 280K XC70 & installed this part VS the Volvo part. I installed it along with the Volvo Oetiker clamps from FCP & everything was a nice tight fit, no bunching up of the rubber elbow/under the clamps etc. I've only run it a thousand or so miles but all is well, no leaks, no melted rubber, nothing abnormal.

I don't say this to endorse URO's entire line of parts for P2 Volvo's, but this is one instance where I would say it is quite prudent to go with the cheaper alternative.

I realize there are 2 variations of the PCV kit, but it is based on engine number, not turbo vs N/A, so the poster of this topic may or may not even be eligible for the kit which contains the pricey elbow I'm going on about. Either way, I feel it's my duty to share avenues on which I've found money savings with others.

Post by **abscate** » 27 Jul 2019, 03:43

Pete...i truly hope that part works for you, but we have scores of people with URO rubber parts in oil applications reporting 12 month lifetimes. That part is buried under three hours of labor, do using my 25 an hour number, for me, I would go Volvo there and cry once

MDK · Post by **MDK** » 27 Jul 2019, 05:17

Well... MDK here. If you're not having an issue and the engine has passed 2 tests, what are you worried about?

Post by **- Pete -** » 27 Jul 2019, 09:01

Abscate, it’s a good excuse to purchase an inspection camera!

When my wife asks what this thing is for.

I’ll courageously report anything amiss & will inspect Uro elbow at every service.

I too avoid the Uro stuff, in fact I think the only other Uro parts I have on any of our cars are their dipsticks.

At this point of this vehicles life I’m sorta using it to experiment with various products so I can sorta know what to expect to see out of our other 3 P2’s.