Is the glove test over the oil filler a sufficient diagnosis of PCV? [Archive]

bugeye

03-19-2015, 12:00 PM

The action level is a negative pressure of: - 0.2 kPa = - 0.8"H2O. This is a very low pressure and measured at idle with a warmed engine. Minimum rec'd after service is - 0.5 kPa = - 2.0"H2O. Still a very low pressure. Our '04 XC70 at 105000 miles is just due for PCV service at a measured negative - 0.7" at idle and 2000 RPM . My sisters '01 XC70 (Florida car) at 95000 miles measures -1.4" at idle and -0.6" at 2000 rpm. Measurements using a differential pressure gauge attached at the dipstick tube. Both cars look similar using a plastic baggie over the oil filler opening. Volvo dealer will be happy to measure and rec'd service. I was quoted ~ $1000 for PCV replacement. I'll probably due it myself.

JRL

03-19-2015, 12:41 PM

All that means is it's clogged, how much you need a manometer.
Dealer should let you check it while you're there

howardc64

03-19-2015, 01:39 PM

The glove test comes positive - it is sucked in.

Sucked inwards means negative pressure and good ventilation for idle circuit. Positive pressure will inflate.

For boost circuit, need to step on brake and gas together briefly to get to higher RPM while not moving (I was thinking rev RPM In P or N would be okay too?). I don't know if too much pressure will suck the glove in (never tried). Youtube has a guy doing it with a home made vacuum indicator.

https://www.youtube.com/watch?v=d0SoAjX2xwM

But check often with high miles on PCV circuits, I've seen it go from good ventilation to clogged in the blink of an eye mileage wise. Luckily, I haven't read much about P2s with clogged PCV leaking at RMS (Rear Main Seal) like the previous gen.

JRL

03-19-2015, 02:45 PM

A hose can crack (especially that 10" curvy upper line) and you go from good pressure to no pressure in a second.
Leave it that way for too long and you all know nasty stuff starts to happen!

2002V70XC

03-19-2015, 10:34 PM

For boost circuit, need to step on brake and gas together briefly to get to higher RPM while not moving (I was thinking rev RPM In P or N would be okay too?). I don't know if too much pressure will suck the glove in (never tried). Youtube has a guy doing it with a home made vacuum indicator.

Can a PCV system have 1 bad circuit and 1 good circuit at the same time?
I found out my car needed PCV system replaced when I did the glove test for idle circuit and there was pretty much no suction of the glove but it wasn't blowing the glove.
I also did the boost circuit test using glove and I was on P + pushing the gas. There was some extra suction when I did that. Cheers

vtl

03-20-2015, 07:55 AM

Can a PCV system have 1 bad circuit and 1 good circuit at the same time?
I found out my car needed PCV system replaced when I did the glove test for idle circuit and there was pretty much no suction of the glove but it wasn't blowing the glove.
I also did the boost circuit test using glove and I was on P + pushing the gas. There was some extra suction when I did that. Cheers

Yes, on turbo engines, where intake pressure is positive when turbo kick in, PCV routes gases to turbine's intake. On idling engine, when intake's pressure is negative, PCV still throws gases in it.

Scopeman

03-20-2015, 08:05 AM

JRL

03-20-2015, 08:18 AM

Well, even though a complete breather replacement has never been in the service manual
The PTC nipple is supposed to be removed and cleaned (or replaced) at the 90K service (IIRC)

howardc64

03-20-2015, 09:49 AM

Yes, mine had OK vacuum at idle, but cruise or boost was poor to bad. One of the most important areas in my mind, is the "PTC Nipple", down on the pipe behind the engine.
If it is partially clogged, the boost circuit will be significantly impaired.

Yes, make total sense. PTC nipple is the main source of higher vacuum needed with the higher blowby at boost. So definitely want to check that at PCV rehab.

Both my 01s had completely clear PTC air channel even past 100k miles. However, both developed mysterious oily wetness around outside. Maybe the PCV hose and/or the PTC nipple mounting seal on the air pipe might be the leak source.

Xheart

03-20-2015, 06:11 PM

All your comments are very helpful.
Thank you for clarifying the glove test.

It brings up following:

There is an electrical connection at PTC, what is it reading, and what parameter is it in VIDA?

There is often a sputter for some 30sec at the TCV/Boost control value (pierburg) at the engine start -- TCV is hung at the air box. Is sputtering a sign of TCV failing -- any relevance to PCV boost circuit?

howardc64

03-20-2015, 07:11 PM

There is an electrical connection at PTC, what is it reading, and what parameter is it in VIDA?

PTC connector is just power for a resistive heating element. I've read that it prevents moisture from freezing in the PCV tube in cold temperature.

2002V70XC

03-21-2015, 04:42 AM

Yes, on turbo engines, where intake pressure is positive when turbo kick in, PCV routes gases to turbine's intake. On idling engine, when intake's pressure is negative, PCV still throws gases in it.
Thanks vtl! Great explanation.

2002V70XC

03-21-2015, 04:53 AM

The PTC nipple is supposed to be removed and cleaned (or replaced) at the 90K service (IIRC)
Hi JRL,
Do Volvo dealers do such service? Unless there is an easy way of removing the PTC nipple, I see no point in removing it for cleaning because if the nipple get damaged or something then you gotta replace the whole intake tube right?

vtl

03-21-2015, 06:22 AM

I removed intake pipe yesterday, a bit tough job (no much room for hands and movements), but doable. PTC nipple was clean, I sprayed it with cleaner without removing from pipe. It actually has a large hole, if it becomes clogged the rest of PCV would be clogged for a long-long time.

PTC is a pure mechanical part (+ heating element), if it cracks I'd just use JB Weld to fix it.

Also found by occassion that strut brace mounts sold by FCP in Meyle struts kit were separated. Only 9500 miles and 6 months in car. I was suspecting the quality, since almost everything else in that kit already failed, so kept old OE mounts on the shelf...

347stang

03-22-2015, 06:31 AM

Good Morning All,

I have been following this post and decided to do the rubber glove test over the oil-fill hole. The glove starts to inflate, with that in mind I am going to clean/replace my PCV system.

My question is which of the following two kits would do the trick.

1.www.ipdusa.com/products/11110/124569-pcv-breather-system-kit-1999-2001-c70-s60-s70-v70-xc70-turbo

2.www.fcpeuro.com/products/volvo-pcv-breather-system-kit-c70-s70-v70-s60-turbo-v70t100

The only difference I see besides the price is the additional hose that IPD's kit has. Is the additional hose necessary, or would that have to be determined once its apart?
I would need to have the kit before taking the car apart, due to this being my daily driver at this time.
An order placed at either of the above would take a little over a week to get to my door.

Thank you,

Astro14

03-22-2015, 06:53 AM

I would get the extra hose. Internal parts of it are plastic and age/break. It's a pain to replace, with sealing rings and coolant going through it, but do this job once, and do it right (or in my case, once on each car...)

Scopeman

03-22-2015, 04:00 PM

I purchased the IPD kit, and was quite pleased! It contained everything needed, all the little bits and pieces, way too many to list. I can recommend it it without reservation!

2002V70XC

03-23-2015, 08:12 PM

My question is which of the following two kits would do the trick.

1.www.ipdusa.com/products/11110/124569-pcv-breather-system-kit-1999-2001-c70-s60-s70-v70-xc70-turbo

2.www.fcpeuro.com/products/volvo-pcv-breather-system-kit-c70-s70-v70-s60-turbo-v70t100

The only difference I see besides the price is the additional hose that IPD's kit has. Is the additional hose necessary, or would that have to be determined once its apart?
IPD kit is better because that additional hose you are talking about (http://www.ipdusa.com/products/6613/113928-pcv-breather-hose-assembly-p2-5-cylinder-turbo-2002-2004) is not cheap at all and its best to replace it. I'm not sure about the quality as it said aftermarket. I would go for it though! Its much cheaper compare to PCV kit for 2002 XC70.
The photos don't show the PCV banjo bolts but they were included in the kit I got from IPD.
Only 2 left so be quick!

Xheart

03-23-2015, 08:58 PM

PCV Job is for serious DIYers.
Do not use a kit with aftermarket parts -- weak link. Premature failure of seals, and hose.
Use correct size and type of clamps.

Only use Volvo if it is indeed your car. "Do it once, do it right", I agree!
Volvo is not expensive. Try this http://volvopartslisle.com/assembly/82801454/Crankcase-Ventilation.

Also purchase a manifold gasket.

IVIUSTANG

03-24-2015, 10:33 PM

2002V70XC

03-25-2015, 02:07 AM

I removed intake pipe yesterday, a bit tough job (no much room for hands and movements), but doable.

That doesn't sound right from an experienced DIYer. Was it when you tried to remove it at the connection with the air filter box? The clamp at the turbo shouldn't be hard with 1/4" Ratchet and the right size extension right?

JRL

03-25-2015, 05:34 AM

vtl

03-25-2015, 05:39 AM

That doesn't sound right from an experienced DIYer. Was it when you tried to remove it at the connection with the air filter box? The clamp at the turbo shouldn't be hard with 1/4" Ratchet and the right size extension right?
I have big hands. Disconnecting small pipes and heater connector was the hardest part for me.

troyhyde

03-25-2015, 05:57 AM

Correct me if I am wrong, but what I gather from this thread is that these engines should NEVER have positive crankcase pressure both from idle and all the way up to the redline. Is my presumption correct?

Jesse

Only time an engine with a good PCV will show pressure is when the valve guides / seals or piston rings are leaking more pressure than can be evacuated, namely this is an engine with high mileage or flat worn out!

Just went through the inlaws 98 T5 S70 PCV, it still has minor vapor escaping via the dipstick. I noticed when the intake manifold was off there was a lot of oil migrating down the intake valves, charge pipes were dry. Engine has 220k and is nearing its day of reckoning.

Xheart

03-25-2015, 08:51 AM

Only time an engine with a good PCV will show pressure is when the valve guides / seals or piston rings are leaking more pressure than can be evacuated, namely this is an engine with high mileage or flat worn out!
...

I am reading it something like this troy:

Only time an engine with a good PCV [at idle or rev] will show [glove inflate at the oil filler] is when the valve guides / seals or piston rings are leaking more pressure than can be evacuated, namely this is an engine with high mileage or flat worn out!

Yes?

2002V70XC

03-25-2015, 04:04 PM

Correct
Why?
I just had a read about this (http://auto.howstuffworks.com/positive-crankcase-ventilation-system.htm) and i'm still not so sure. PCV stands for "Positive Crankcase ventilation" so if the engine didn't have any positive crankcase then why would they name it like that?
Another thing i'm confused is that my torque app has a gauge showing vacuum level. I noticed that it was about 23 in/Hg when my car was in Drive and stopped at the traffic, it went from negative (counted in in/Hg) to positive boost (counted as psi) when I accelerated to move the car faster. So I guess that at idle you would have negative vacuum and you would have positive vacuum when the turbo is boosting?

IVIUSTANG

03-25-2015, 04:16 PM

Why?
I just had a read about this (http://auto.howstuffworks.com/positive-crankcase-ventilation-system.htm) and i'm still not so sure. PCV stands for "Positive Crankcase ventilation" so if the engine didn't have any positive crankcase then why would they name it like that?
Another thing i'm confused is that my torque app has a gauge showing vacuum level. I noticed that it was about 23 in/Hg when my car was in Drive and stopped at the traffic, it went from negative (counted in in/Hg) to positive boost (counted as psi) when I accelerated to move the car faster. So I guess that at idle you would have negative vacuum and you would have positive vacuum when the turbo is boosting?

The vacuum gauge you mention has nothing to do with crankcase pressure at all, that is intake pressure. As an FYI 23 in/Hg is a very good reading for idle, anything 20 or greater is considered efficient. Also think about this, the PCV system is taking excess pressure out of the system, which leaves you with a slight vacuum in the crankcase; so it is correctly named a positive crankcase ventilation system :)

Jesse

2002V70XC

03-25-2015, 06:59 PM

The vacuum gauge you mention has nothing to do with crankcase pressure at all, that is intake pressure. As an FYI 23 in/Hg is a very good reading for idle, anything 20 or greater is considered efficient. Also think about this, the PCV system is taking excess pressure out of the system, which leaves you with a slight vacuum in the crankcase; so it is correctly named a positive crankcase ventilation system :)

Jesse
Thanks for point out the difference :) and helping me understand it a little bit more.