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P80 PCV System Repair on a Volvo 5-cylinder (-1998)

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

This topic is in the MVS Volvo Repair Database » PCV System Repair on a Volvo 5-cylinder
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jblackburn
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Re: PCV System Repair on a Volvo 5-cylinder

Post by jblackburn »

Looking back, I wish I'd been able to find that wrench. For some reason, that was the only one missing from my tool kit. That and the swivel joint for my little wrench. With those two, I'd have been able to do it much easier I think.

MAF is the mass airflow sensor, on the tube just out of the airbox heading towards the turbo.

You can see one of the knock sensors hiding just behind the oil separator box just here; the other is on the right side, both are under the intake manifold.

https://www.matthewsvolvosite.com/forums ... d=4318&t=1
^Take a look and see for yourself.

I didn't have any problems with the hose clamps that I was sent by IPD - as long as you don't tighten them down too tight, but they're a higher quality than most of the cheapo ones you can buy at a parts store.

As for the valve stem seals, one of our members did a great write-up here:

http://sites.google.com/site/incarvalve ... placement/
'98 S70 T5
2016 Chevy Cruze Premier


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!

obayha
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Year and Model: V70 1999 Base
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Post by obayha »

Thanks, I will look into the other things tonite. Now it's time to get off work early, go get the parts and fix it. But I am a glutton for punishment.... I will pick up a 2006 V70 T5 next weekend for the wife to drive. It is like new to her. Only 48,000 miles. This means I need to learn to work on them faster. LOL>>>>>.
1998 V70 T5 331,000 :( Her last day was on 3 cylinders.
New to me 1999 V70 NA 163,000 Now at 217,000
2006 V70 2.5T in driveway (WIFE'S)
1982 Toyota FJ40 Land Cruiser

PerthX
Posts: 24
Joined: 17 April 2010
Year and Model: 850T 1995
Location: North Florida

Post by PerthX »

Had a mechanically minded friend (expert) do the PCV system as shown here while I bumbled along trying to learn. Justin's write up and the one from Lakeside were a great help. We also found it unnecessary to remove the coolant hose, remove radiator fan shroud or lift the car. Only real pain in the butt bolt was the dipstick bolt...never did find the other one referenced. I have an 850T '95 so maybe that was the difference.

We used the PCV kit available at FCP which seemed to have a couple extra elbows etc. The kit had every part, hose and clamp we needed.

Our main concern was trying to stop an oil leak that was due to a split elbow on the oil trap due to over tightening of clamp by a previous hack! We cleaned everything, EGR, PCT etc and thankfully nothing was as bad as pictured here. We cruised thru it but took our time cleaning the EGR and PCT etc and with the Oetiker clamps so as not to make the same error as previously seen. Had we not stopped to clean and repair various assorted non related items along the way, I think we would have been done is around 4.5-5 hours....

My friend pulled apart the old oil trap to see that there was absolutely NOTHING inside. Who knew?

Meanstreets
Posts: 30
Joined: 20 March 2010
Year and Model: 1997 855 T5 Wagon
Location: Madison, WI

Post by Meanstreets »

I did this repair when my bro came to visit two weeks ago. aside from losing a 10mm socket somewhere (looked all over, but couldn't find where it went) everything went pretty good. We also replaced the air inlet hose w/ sensor going from the air filter to the turbo inlet.
I agree that the wobble sockets were absolutely necessary. I didn't remove any coolant hoses. We had the car on ramps to get better access to the bolts underneath, but those were still a real pain! Also, removing the fuel rail wasn't necessary. But removing the fuel lines and having the proper replacement was. I also replaced the gasket on the oil filler cap. Everything is back together and works fine, but I still need to replace the oil cooler line that runs from the top-rear left of the radiator to the left side of the oil pan. It is hidden right above the subframe, and I can't figure out how to get it off. Any suggestions?

jnztuning
Posts: 2
Joined: 4 May 2010
Year and Model: 2000 XC70
Location: PA

Post by jnztuning »

This is a great write-up on maintaining the Volvo PCV system which gave me a lot of knowledge and I'm sure has helped countless others.

However, ever since I bought my '00 XC and came across this weak point, the resounding question I've had is "Hasn't anyone come up with an alternate solution that isn't such a crutch??".

I've had some issues with my recently purchased XC which I'm working my way through, but once I'm done with all of this stuff, I want to tackle this aspect. I'm not looking to "reinvent the wheel" so to speak if it's already been figured out.

Is there anyone who's reworked their problematic system into something less of a headache to maintain?

I was thinking of utilizing a one-way check valve off of another make/model and then routing it into a catch can with baffles that can be easily drained without all of this headache.

I've owned mine for two weeks and with the failure of the stock radiator, took a day to modify the cooling system so that I could eliminate this horrendous design that most european manufacturers use (meaning eliminating the pressurized coolant recirculation tank). I can't stand this setup (used to ashamedly own quite a few VWs 15+ years ago) and refused to keep it on the car.

Has no one looked into this (the PCV system)??

jblackburn
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Post by jblackburn »

Yes and no. The design is annoying, but many are actually like this. Ford uses a very similar system on some models. From what I understand, the 2 holes at the engine block itself, if lengthened to place the canister elsewhere, would reduce the effectiveness of the venting system, and probably clog up or reduce the ability of the system to vent these pressures. So you'd still be in the same situation, blowing smoke or oil/seals out, even if the breather box would be easier to get to without removing the manifold.

The hose from the PTC to the box itself, and the left side of the manifold, could be placed elsewhere, and I agree that one is a stupid, pain in the rear design.

There's a little bit more about how the oil separator box works here:
https://www.matthewsvolvosite.com/forums ... w=previous
'98 S70 T5
2016 Chevy Cruze Premier


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!

PatternFlyer
Posts: 91
Joined: 9 June 2008
Year and Model: 99 V70 XC
Location: Pittsburg, KS

Post by PatternFlyer »

My 99 V70 XC needs the PCV work, but have a few questions to ask.

IPD include PCV Hose assembly while FCP kit does not. So, going with FCP kit mean I have to clean the entire PCV hose assembly individually?

I don't want to order more parts and wait at least 3 days with car disabled.

What happens if the seal breaks?? I have very light/little smoke during cold start. and gas out to the dip stick.

How much difference does 99 V70 XC (turbo) has compared to 850 ??

jblackburn
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Post by jblackburn »

As far as I can tell, the two kits look more or less identical with the exception of the hose clamps. I saw that discussion earlier, and figured I'd let the rest of you join into that one. I'm not sure who makes the hoses FCP includes in their kit. I used IPD's kit because it was cheaper.

Whatever you do, buy a couple extra clamps from the auto parts store for anything else you may remove and clean in the process.
IPD include PCV Hose assembly while FCP kit does not. So, going with FCP kit mean I have to clean the entire PCV hose assembly individually?
The intake air hose? No they don't. That hose needs to be removed and cleaned anyway, and you should be good to use it again. You don't necessarily need to remove the PTC from the hose, but I thought it was pretty easy. Pull straight up and don't apply a lot of force, and you won't break anything. To put it back in, push around the edges of the rubber seal with a flathead screwdriver, and you'll get it to go right back in.
How much difference does 99 V70 XC (turbo) has compared to 850 ??
Your car's PCV system is going to be exactly like my S70, the only difference will be your electronic throttle module. That will have to be removed from the car and set out of the way...make sure you set it in a clean area. Some older 850's were different in little ways, mainly in that the earlier models had EGR valves and an additional part to clean.
'98 S70 T5
2016 Chevy Cruze Premier


A learning experience is one of those things that says, "You know that thing you just did? Don't do that."

mercuic: Long live the tractor motor!

1997volvo850
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Post by 1997volvo850 »

jnztuning wrote:This is a great write-up on maintaining the Volvo PCV system which gave me a lot of knowledge and I'm sure has helped countless others.

Is there anyone who's reworked their problematic system into something less of a headache to maintain?

Has no one looked into this (the PCV system)??
This is a great idea. I think we would really need to understand the system and what goes wrong with it.

I've got two cars that my Volvo dealer tells me I need to replace the PCV system. The main symptom that triggers the "you
need a new PCV system" response is the smoke out the dipstick. I've been following a few threads on this site and
numerous people have replaced the PCV system AND still ended up with smoke coming out of their dipstick.

A few us think the PCV system is not designed to handle the blow by from older cars as the valves and rings get older.
In the PCT valve thread we were discussing ways of capturing or reducing the smoke emanating from the dipstick tube.
I tried to slightly enlarge the opening on the PCT valve but this does not help. The problem is the tiny amount of vacuum coming
from the intake during idle is insufficient to handle the blow by gasses.

I agree with you that the design of the PCV system appears strange to us non Volvo folks. The system almost seems like
it was designed with the Volvo service department in mind.

I'd be game for coming up with modifications to make maintenance of the PCV system easier. We need to collect the experience
of the individuals that have changed the PCV system. Several have said that nothing was clogged when they changed it.
So why did they change it in the first place?

It would be good to know all of the locations that get clogged. Does the tiny vacuum tube to the intake get clogged first?
My PCT valve was clogged shut.

The modifications I would consider would be 1) adding fittings to allow cleaning of areas that clog. 2) addition of vacuum to
reduce/eliminate smoke emanating from dipstick.

Sounds like you want to move the oil separator box. The idea of having it on the engine allows oil to drain back into the
crankcase. If this system was designed correctly there would be little service require, and definitely not changing the PCV
every time someone sees smoke coming from the dipstick..

Trenchcoat
Posts: 15
Joined: 6 May 2010
Year and Model: 850, 1996
Location: Louisville, KY

Post by Trenchcoat »

I just got the kit in from IPD and am planning on doing the overhaul this afternoon. I'm hoping I can get by without having to lift the car. All I have is a 2-ton floor jack. Hopefully this process will go by with a minimum of broken parts and cursing. :|

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