PCV System Replaced--Mixed Results

[Carllay]

This past weekend I had the PCV System (complete IPD Kit) replaced on my 2004 XC70 (102K miles) by my indy mechanic. Prior to replacement, I had positive pressure on the idle and cruise circuits with the glove test. The good news is now I have a strong negative pressure on the idle circuit but the same positive pressure on the cruise circuit (glove is blown off). My mechanic indicated the sump port was cleaned out prior to installing the new breather box and he thinks the problem may be due to an obstruction in the Y hose connector (check valve??) prior to the return to the intake manifold.

This morning I'm going to buy screw clamps to replace the crimped clamps before I check the Y fitting.

Any other thoughts on why I'm still having this issue?

Thanks to all, especially Howard and Jason, who have posted on this topic.

Sincerely,

Carl

[JRL]

Not really except something was not installed properly

[Scopeman]

Was the PTC Nipple removed and cleaned? If not, that would be my first check.

[Carllay]

Scopeman,

There was a banjo fitting in the kit and it was replaced but I don't know about a PTC nipple. BTW, what is the translation of the acronym PTC? Where is it located located?

Thanks,

Carl

Carl

[Carllay]

This afternoon I removed the y connection aka the booster vacuum ejector I mentioned in my original post. The stem/line connector that comes in at a 45 degree angle is completely blocked. Just got off the phone with Volvo parts and was told the stem should allow air to easily flow. Hopefully replacing this part will take care of my issue.

[JRL]

Was the PTC Nipple removed and cleaned? If not, that would be my first check.

Of all the breather parts the PTC nipple MUST be replaced not "cleaned". You think it's clean but because of the very tiny passage, I can guarantee that it's not

[Carllay]

In speaking with IPD regarding the components in their PCV breather kit, i was told a PTC nipple is not included.

[kutcht1]

So, where does one get that magical PTC nipple and where is it? I have been reading on this as I am gathering parts to do this task and have not heard of that part.
TomK

[JRL]

Where would you think?
Comes with almost every kit out there, get it at your Volvo dealer, or at any shop that sells Breather parts and kits.
Nothing magical about it, it's a bolt with a VERY small hole

[Carllay]

Howard's excellent Volvo help site includes the following statement for PCV system maintenance:

"First, there is a banjo fitting that commonly clogs. It clogs because there is only a 2mm diameter channel where the oil vapor runs through. So it doesn't take much to clog it."

This part is included in the IPD kit. Could this be the same part as the PTC fitting?

Carl

[howardc64]

Here is a reference pic to where the PTC is. PTC is where the PCV gets its vacuum in cruise circuit. Its located just in front of the turbo on the fresh air pipe from the air filter box. For clarification, this isn't the banjo bolt with the vacuum hole in it.

The PTC is basically a vented hole (pretty decent sized diameter, at least 1/4"?) and has a heated element in it to eliminate any water condensation I think. If this is clogged, the major vacuum source from the turbo would be blocked.

http://www.volvoxc.com/forums/showthread.php?14675-Pcv-ptc

[Scopeman]

OK, I may have not been clear, the PTC nipple is down behind the engine on the turbo intake pipe. It has a hose from the breather system and an electrical connector. As I understand the breather system function, at cruise/boost, the air flow over this fitting creates a low pressure area and pulls gasses from the breather system into the intake air. These gasses are oil laden and will clog this part. http://www.ipdusa.com/products/9736/120407-turbo-air-intake-hose-p2-5-cylinder-turbo It is this part. I may be using the wrong term for the electrical part, but I believe it refers to "Positive Temperature Coefficient", I suspect it measures the air temp.

[kutcht1]

OK, that is more clear now as this is my first Volvo and first turbo vehicle I have been reading till I can not any longer to learn about this beast. Some have even removed the PTC altogether. Many threads on cleaning it but you say that it should be replaced which is the entire air tube? Can just the sensor be removed, cleaned, and replaced since it is over $100.

I also found this info that spells it out better.

It is the heated crankcase vent nipple (also referred to as the Positive Temperature Coefficient heater nipple) used on 90 and later where the air heater tube is deleted. The PTC nipple is mounted in the cold air intake pipe that runs from the air filter box to the turbo. It is in the elbow of the pipe, nearest the turbo. It has one or two vacuum hoses connected that run back to the oil trap. There is also an electrical connector about the size of a spark plug. Volvo decided that the preheat system which was thought would prevent throttle icing would not work on intercooled models due to cooling effect on air through the intercooler before it goes into the throttle. The heater is to vaporize the moist air that comes out of crankcase after start up and while driving in very cold weather. The LH fuel injection system on that car doesn't use the Intake Air Temperature sensor. Occasionally one can experienced a pressurized manifold with too much pressure in the crank case, causing oil to blow from the filler cap or the seals. This can be caused by the PTC nipple valve which can clog. All of the turbos since 1990 have a PTC and they tend to get clogged during cold weather.

TomK

[JRL]

We use an XC90 T6 part that costs about $25 and mate it to the large pipe and save over $150
(That piece includes the nipple)
The Large tube is $200!!!!! not $100

[kutcht1]

That is great to know JRL! Can you give me/us that part number or link and how you mate them?
I was going from this link: http://www.ipdusa.com/products/9736/...cylinder-turbo
That part is from IPD and is $101.95 which is the large pipe and the PTC nipple.
TomK

[JRL]

No it's not and that has NOTHING to do with the breather system.
Let someone do the breather who at least knows what parts to use!

[kutcht1]

So is everybody doing this wrong and not really know what the PTC nipple is? Again, JRL is you have a way to do this for $25 please enlighten us as I am interested in knowing as you seem to know everything there is about a volvo. I am also looking at this pdf which points to #6 as the PTC on that exact pipe.

TomK

[Scopeman]

The PTC nipple is the appendage sticking out of the tube pictured in the IPD picture. It does indeed connect to the breather system! And, if plugged, will cause high breather pressure in cruise or boost.

[kutcht1]

So that is the PTC nipple and JRL is referring to a different nipple then which looks to be in the long horizontal tube near the thermostat housing. I would like to learn more about his other nipple JRL is talking about and his $25 XC90 fix alternative maybe even with a photo!
TomK

[howardc64]

It seems like some of the references discuss banjo bolts and PTC nipples interchangeably. They are not the same at all. And a bit of PCV operational theory on this car would be helpful. Here is the exact picture of the PCV system for this car

http://www.r-series.org/pcv.jpg

The Banjo bolt is labeled part #11 and #14 in this diagram. #14 has a 2mm pin hole that is connected to the intake manifold. This is the source of vacuum during idle. I've not taken out #11 to know if it has the same pinhole design and where the air channel is attached. Perhaps someone else can chime in.

The PTC nipple is connected at the clamp #13 and is located on the air tube between the air filter box/MAF assembly and the turbo (just a few inches from the turbo end connection). The PTC nipple is just an open hole (about 1/4" diameter) with a heating element (this is why it has a 2 wire connector on it). This is the source of vacuum when cruising. It supplies the necessary higher vacuum to vent the higher blowby.

The supplied vacuum from either the banjo bolt hole or PTC nipple is routed to the oil trap at the port just about #1 in this diagram. The vacuum provides suction to get rid of blowby pressure at #3 for the block and at #7 for the head. The blowby is an oily vapor and the oil trap filters out what it can and is drained back into the oil pan at #4. BTW, the post combustion blowby vapor has a bunch of bad stuff that dirties your oil. Modern cars puts it back in the oil for low maintenance. I've read VW/Audi enthusiasts with turbo engines like to put a catch can and dump out all this junk periodically rather than putting it back in the oil and the engine oil would stay much cleaner.

I have encountered blockage at the banjo bolt pin hole on the intake manifold. There is a low spot on the intake manifold where the pin hole is vented and the dirty oily vapor pools there and eventually block the hole. The intake manifold has dirty oily vapor in it because when PTC nipple is source of vacuum under cruise, oily vapor enters before the turbo and dirties up everything afterwards - turbo, tube over top of engine, intercooler, intake manifold. I guess oil trap doesn't catch 100% of oil in the vapor to put back in the oil pan. Worse yet, where ever there is a low spot, the combination of oil presence and gravity tends to pool and rot the rubber, seeps and leak at a connection or block some necessarily channel.

I have also heard of oil drain channel becoming blocked deeper inside the block/oil pan beyond just the drain port opening on the engine and requires taking off the oil pan to clean it. I myself haven't had blockage at the PTC nipple on 2 cars although I've had some oil leaks around where its attached at the air pipe. There is a rubber grommet that seems to leak over time. I read someone sealed it with RTV.

Anyhow, I hope this makes it clear that banjo nipple and PTC nipple are 2 different things. For those that already knows this, sorry for the redundant explanation. But I thought I clarify for those less familiar.

[kutcht1]

Thanks a lot Howard! That is the info I think I was needing to have clarified. JRL had me wondering which was the PTC nipple and it actually the banjo bolt. You are a huge help to those of us that are learning about this vehicle and like to handle the maintenance themselves as these things are not difficult, they just need information, patience, and tools.
TomK

[howardc64]

Actually, the thing I never understood are the following. Perhaps someone with better understanding can chime in

- I don't believe there is any check valves between the idle and cruise circuit. I would then assume which ever circuit was providing more vacuum does the heavy lifting at that moment?
- I've always wondered why the PTC vacuum source wouldn't just be much greater than the banjo bolt hole? Perhaps its all just by designed with the proper sizing and venturi effect etc...

BTW, I have a 01 VW MK4 1.8T (turbo) engine that also routes the PCV similarly with 2 vacuum circuits. One at intake manifold and the other front of the turbo. Seems like typical PCV design for turbos.

[Tahoe_XC]

Actually, the thing I never understood are the following. Perhaps someone with better understanding can chime in

- I don't believe there is any check valves between the idle and cruise circuit.

Is this not the function of the rattle valve in the Banjo bolt that mates to the manifold?

[2002V70XC]

very informative thread! Thanks guys!
I'm planning to do PCV replacement using IPD kit but i'm wondering if I should replace the Banjo bolts #11 and #14? My thought was that its just a special bolt with a hole going across it so if the hole isn't blocked then it should be fine for reuse?
Btw, IPD listed it but it said 1 unit per car: http://www.ipdusa.com/products/6616/115127-pcv-banjo-bolt

[howardc64]

Is this not the function of the rattle valve in the Banjo bolt that mates to the manifold?

hmmm, wasn't aware there was a rattle valve inside. Thought it was a solid piece. Its been awhile so perhaps I don't remember :)

[Xheart]

...
I have encountered blockage at the banjo bolt pin hole on the intake manifold. There is a low spot on the intake manifold where the pin hole is vented and the dirty oily vapor pools there and eventually block the hole. The intake manifold has dirty oily vapor in it because when PTC nipple is source of vacuum under cruise, oily vapor enters before the turbo and dirties up everything afterwards - turbo, tube over top of engine, intercooler, intake manifold. I guess oil trap doesn't catch 100% of oil in the vapor to put back in the oil pan. Worse yet, whereever there is a low spot, the combination of oil presence and gravity tends to pool and rot the rubber, seeps and leak at a connection or block some necessarily channel.
...


+1
Would you replace the bongo bolt or clean the pin-hole clog and re-use?

In support of good work of our DIYers -- a cleaned PTC, vacuum connections, and electrical ports...

6463 6464 6465

[JRL]

ALWAYS replace as it cannot be cleaned thoroughly/perfectly
What take a chance for 15 bucks?

[Tahoe_XC]

hmmm, wasn't aware there was a rattle valve inside. Thought it was a solid piece. Its been awhile so perhaps I don't remember :)

Yes, 03- has a two different banjo bolts, the one that connects to the manifold contains a rattle valve, closes under boost. I agree with JRL on most things, all parts on the PCV system should be replaced, particularly the hose assembly it can not be cleaned reliably, and the plastic hose portions deteriorated from thermal cycles. However, the banjo's I do clean. Even the rattle valve. Soak overnight in gas and use a drill bit or two, some air and you are good for another 100k

[sjonnie]

Actually, the thing I never understood are the following. Perhaps someone with better understanding can chime in

- I don't believe there is any check valves between the idle and cruise circuit. I would then assume which ever circuit was providing more vacuum does the heavy lifting at that moment?
Exactly, I believe they put a check valve in with the engine from 2003 but earlier engines don't have that, the air flow is just restricted by the size of the hole.


- I've always wondered why the PTC vacuum source wouldn't just be much greater than the banjo bolt hole? Perhaps its all just by designed with the proper sizing and venturi effect etc...
Because the throttle plate restricts the vacuum in the air intake, so if the throttle is closed the intake manifold has much higher vacuum than the intake air supply and so won't draw enough air through the PTC / PCV system to ventilate the crankcase.


BTW, I have a 01 VW MK4 1.8T (turbo) engine that also routes the PCV similarly with 2 vacuum circuits. One at intake manifold and the other front of the turbo. Seems like typical PCV design for turbos.
Correct, if you are going to have positive pressure in the manifold (turbo) then you can't run a PCV system off the manifold, however with the throttle plate closed there is not enough vacuum in the intake to depressurize the crankcase and so you much have an alternative source of vacuum at idle which the manifold can supply.

[sjonnie]

Would you replace the banjo bolt or clean the pin-hole clog and re-use?
Clean with kerosene and it'll be fine.

[Astro14]

Clean with kerosene and a .22 caliber bore brush (fits perfectly), or just buy the kit from IPD...

[Carllay]

In light of the all the comments subsequent to my original post after replacing the PCV components on my 2004 XC70, today I took the vehicle to Don Beyer Volvo in Falls Church, Va and requested the PCV system to be checked.

I quote from the notes on the service ticket: "Customer requested the PCV system to be inspected on the boost side. Tech inspected the PCV system. Customer is advised the PCV system is operating as per manufacturers specs; suction at idle and pressure when accelerating."

[bugeye]

Our '04 XC70 has ~ 100k miles with what I believe the original PCV system. With the discussions of crankcase positive pressure and blown cranckcase seals, I have been measuring the crankcase pressure a few times over the past year. I use a low pressure gauge with a tube into the dipstick hole. At idle pressure negative at -0.8" water and in gear (brakes on) at 2000 rpm pressure more negative than -1.0" water. I have never seen a specification for crankcase pressure from Volvo.

[Carllay]

Bugeye,

I was surprised by this response and plan to locate a source to get the actual specifictions.

Thanks

[bugeye]

If anyone can post the Volvo crankcase pressure specification or expectation or actual measurments, much appreciated. I have seen and used the glove test. I have watched the YouTube ball in a tube tests. I think a measured crankcase pressure would be more useful in evaluating the health of the PCV system. Somewhat related, my 2007 Volvo S80 V8 pulls a negative -4" water pressure at idle.

[KJAY]

ALWAYS replace as it cannot be cleaned thoroughly/perfectly
What take a chance for 15 bucks?

My dealer says they don't sell the PTC valve except as part of the fresh air tube, which of course is not $15, and IPD said that they don't sell it either. Where do you purchase it?

[skibo]

Is there some accepted way to measure crank-case pressure? i'm thinking of wrapping a small hose in tape, put5int it in the dip-stick tube and running it to a gauge taped to a wiper. What is the recommended range for this if I can measure it?

[Nightair]

I just went thru all this PCV system fiasco with my 2006 XC70, the original breather tube had been broken where it went through the intake, for how long I am unsure as it was not easily seen. Replacing the breather tube caused the VVTs to get plugged and the CEL to come on with associated rattling. Volvo dealer found the Oil Trap full of crud and the crankcase breather plugged with carbon. The Oil Trap,system was replaced and the crank holes unplugged. The trap requires the intake manifold to be removed. IPD and ARD sell replacement kits including the intake gasket. The dealer removed and cleaned the VVTs and flushed the oil system. The cars fuel economy has improved and it runs smooth and doesn't surge at high speeds as it did before. The PCV system was costly but was done right and I am free from anymore problems. Hope this helps.

[Pennhaven]

In light of the all the comments subsequent to my original post after replacing the PCV components on my 2004 XC70, today I took the vehicle to Don Beyer Volvo in Falls Church, Va and requested the PCV system to be checked.

I quote from the notes on the service ticket: "Customer requested the PCV system to be inspected on the boost side. Tech inspected the PCV system. Customer is advised the PCV system is operating as per manufacturers specs; suction at idle and pressure when accelerating."

Can anyone definitively confirm or refute (with evidence) what Carllay was told by the dealer? Other posters have stated that there will always be negative pressure in the crankcase if the PCV breather system is functioning properly. But based on my recent test results and what Carllay was told I'm doubting this.

There are only 71,000 miles on my '04. More than half of that is highway, the rest suburban driving, not very much stop and go, engine usually fully warmed before sitting. Oil has been changed at least every 5,000 miles or annually using Valvoline Durablend (synthetic blend) up to 50,000 and full synthetic since. Since 50,000 miles I've checked my crankcase pressure with every oil change using a latex glove rubber banded on the oil filler. Initially I only checked at idle, but the previous two changes I also had my wife rev the engine to 3,000 rpm and there was still negative crankcase pressure per the glove.

However I recently read that the test really should be done under turbo boost, so after last week's oil change, using my Torque app on my smartphone to measure boost via OBDii, I put the car in Drive, held the brake pedal with my left foot and revved the engine until there was positive manifold pressure. The glove stayed sucked in right up until the boost kicked in and then it inflated, then back to suction when I cut the boost.

So it seems to me that the PCV is functioning as commonly described for idle and for cruise, but boost is another condition, and my results might confirm what the dealer told Carllay. FWIW I pulled my intake tube and checked the PTC. It is open, clean and dry, as is the line at that end from the breather box to the PTC, which is what I would expect seeing negative crankcase pressure under "cruise" conditions. It seems to me, based on Howard's description here on how the system functions, that any blockage impeding flow through the breather system under turbo boost would also impede it under cruise, so it appears there is something else going on that differentiates how the system works under boost from how it works under cruise.

So I guess what I am asking is if anyone else has actually tested crankcase pressure on our cars under boost and maintained negative pressure? That would refute the theory. Or, on the other hand, has anyone, in addition to Carllay, with a fresh PCV system also still seen positive crankcase pressure under boost? That would be further confirmation that this is how it's supposed to work.