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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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Prahudka
Posts: 7
Joined: 28 May 2011
Year and Model: 1998 v70
Location: NY

Re: PCV System Repair on a Volvo 5-cylinder

Post by Prahudka »

tjts1 wrote:I know my PCV system is clogged by the oil seeping past cap but I really don't want to start tearing apart my 210k mile engine. I found a vented oil cap on an amazon at the junkyard which is a direct fit on my whiteblock. Ran a hose from the oil cap to a small catch can and from there the gasses are fed into the dirty side of the airbox. I used a copper elbow from home depot which is glued onto the vent. I was paranoid about leaks so I smeared a bunch of ghastly red RTV at the last minute which was probably not necessary. Anyway, it works so I won't be removing the manifold any time soon.
cheers
Image
Could this possibly be all it takes to reduce the pressure acceptably?

Will this reduce pressure at the dipstick and RMS? You are going to be losing some oil I guess, which is a decent trade off?

Prahudka
Posts: 7
Joined: 28 May 2011
Year and Model: 1998 v70
Location: NY

Post by Prahudka »

850 LPT wrote:Brilliant! Why didn't Volvo come up with this when they designed this engine? :shock:
They did. They also came up with a parking brake that adjust under the console when stretched and a check engine light controlled by a simple switch under the dash. They also figured how to take all that extra space between the engine and the firewall and put it somewhere useful, like between the manifold and the radiator. But, I think they killed all the engineers to suppress the truth.

tjts1
Posts: 673
Joined: 13 November 2007
Year and Model: 96 855 NA 5 speed
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Post by tjts1 »

850 LPT wrote:Brilliant! Why didn't Volvo come up with this when they designed this engine? :shock:

Btw, my '68 Lincoln Continental is vented the EXACT same way.
It probably has something to do with stricter emissions control and the fact that an unknowing owner might try to replace the vented oil cap with an unvented cap. Volvo stopped using the vented cap in the 70s in the US and in the 80s in europe AFIK.
Prahudka wrote: Could this possibly be all it takes to reduce the pressure acceptably?

Will this reduce pressure at the dipstick and RMS? You are going to be losing some oil I guess, which is a decent trade off?
I don't know about the dipstick and RMS because I never had those problems but there are oil drains from the head to the crankcase so you can't reduce the pressure in one without the other. The oil cap has a flame trap like grill inside to stop large droplets of oil. Like I said, its probably not an ideal fix but it works for me. We just took the car on a 500 mile road trip and all seems well. There's no more leaks from the oil cap and a few oily drips at the bottom of the catch can. Everything seems to be working.
Ambitious but rubbish

Prahudka
Posts: 7
Joined: 28 May 2011
Year and Model: 1998 v70
Location: NY

Post by Prahudka »

Autozone has a vent for the mainfold, where it attaches from the oil trap.

I bought one and will give it a go. Apparently I need to cap the old line from the oil trap.

Jeez. a 15.00 fix for something my mechanic said would take 5-6 hours at 60.00 an hour.

bandwcow
Posts: 14
Joined: 7 October 2009
Year and Model: 1995 850GTL
Location: Damascus OR

Post by bandwcow »

Any idea what the intake manifold bolts are to be torqued to? 850 non turbo
Thank you
bill

petek153
Posts: 141
Joined: 27 May 2006
Year and Model: 1992 940T
Location: connecticut
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Post by petek153 »

14 ft lbs (out of Haynes service manual)
92 940 turbo
93 850 GLT sold
94 850 GLT
95 850 GLT
96 850 GLT my parts car (:
96 850 T_BONED ):
97 850 BASE

98expeditionXLT
Posts: 36
Joined: 21 December 2007
Year and Model:
Location:

Post by 98expeditionXLT »

Before tearing your pvc system apart because you have oil under the spark plug cover, replace the oil filler cap. I found the gasket dried out and hardens like a rock forming a poor seal. The oil in the valve cover gets sucked out and pushed under the spark plug cover while driving. Since replacing the oil filler cap with an aftermarket oil filler cap my oil consumption went from one quart every 12-1500 miles to one quart every 3500 miles with 258k on the odometer. I just took my 850 on a business trip from Boston to Toronto with no problem and got 30 miles per gallon on every tankful.

jblackburn
MVS Moderator
Posts: 14043
Joined: 8 June 2008
Year and Model: 1998 S70 T5
Location: Alexandria, VA
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Post by jblackburn »

Before tearing your pvc system apart because you have oil under the spark plug cover, replace the oil filler cap.
DON'T do that if the PCV system isn't venting like it should. If you have smoke from the oil dipstick, DO NOT replace the oil seal cap. You'll start venting out/blowing out your engine seals instead.
'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!

hankbates
Posts: 72
Joined: 2 April 2009
Year and Model: 96-855T, 01-V70T5
Location: Massachusetts
Has thanked: 1 time

Post by hankbates »

I recently fixed my PCV system on the 96-855T, using a FCP kit and a lot of help from this thread. It has 185K, and the PCV had apparently been done about 90K ago, but using parts which were already in the repair shop. The large hose was too short, and the PTC was loose in the socket, so some air leakage into the turbo inlet past the MAF sensor was taking place.
After getting it right, I was pleased to see both an increase in performance and even slightly better gas mileage.

We also have a 2001 V70T5 with about 95K. Both cars have IPD chips, but the 850 has seemed to run stronger. I just figured that when Volvo did the software update to keep me off the Vexedvolvo/etm forum, they had erased all the benefits of the chip flash.

Keeping check engine and other lights off in the 01 has been a recurring problem, with most codes referring to cleaning the MAF sensor. Cleaning it usually fixed things for a few thousand miles, but the issues kept coming back. I had always wanted to swap it out with a used one (a new one was ~$300), but never found one at a low price. I decided to bite the bullet a couple of weeks ago and found to my surprise that they are now available for around $50, internet and eBay, so I bought one. Well, the increase in performance and response I got from plugging the PTC hole in the 850 was minimal compared to the results in the 01! My guess as to Volvo's software update spoiling the IPD flash was apparently wrong....

So now I have both Volvos running as they are supposed to, and I wasn't unhappy before. Thought I should share this.

hankbates
Posts: 72
Joined: 2 April 2009
Year and Model: 96-855T, 01-V70T5
Location: Massachusetts
Has thanked: 1 time

Post by hankbates »

Part number for the $50 new MAF sensor for 99-02 turbos is REPV316708, you can to a search for it...

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