Volvo AWD 850 Forum

INDEX FOR 1/2026(CURRENT) INDEX FOR 2/2005 850 INDEX

[<<]  [>>]


 VIEW    REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

CRAKCASE PRESSURE 850

posted by  TomL on  Mon Sep 22 17:05 CST 2003
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Sun Jul 25 18:24 CST 2010
[RELATED]

I copied this message from the web site mentioned in the reply from Gerald C. I think it points to the source of your problem but needs a little more explaination as to where the PCV valve is.
It is located in the fresh air inlet pipe near the turbo. Folow the large hose form the Air Filter box down toward the turbo. The air inlet pipe connects to a fitting that has a large hose (that goes to the top of the engine near the oil filler cap), a small vacuum line with a rubber elbow, and an electrical connector connected to it. Usually the rubber elbow is shot and the nipple that it connects to is plugged. You will have to run a small drill into the nipple to clean it out. I removed my fitting and used a drill motor to do mine. The vacuum line should have vacuum when the engine is idling. If it doesn't there is a problem where it connects, which I just learned from this message is somewhere behind the power steering pump.
AS far as I know this PCV system does not show up in any Volvo 850 service information and is only mentioned on the vacuum routing diagram as the PTC valve.
Good luck and let us know what you learn.
If someone has a diagram of the PCV system please post it.
Tom

Here is the message I referred to in the beginning

.. posted by Wayne bosman on Tuesday, 20 March 2001, at 7:04 p.m. ...in response to "Re: Sounds like excessive crankcase pressure." posted by Dave E..
Since volvo turbos dont have a flame trap per se, the engine blowby and crankcase pressure are vented through a multi purpose valve that is in the iintake bellows. there is a vacuum line to the valve that gets kinked and porous from the gasses going through it and it often implodes. the valve itself gets plugged up from carbon deposits. try clearing the nipple on the valve. Rout it out with a paper clip or something. the other end of the vacuum line goes to the intake manifold near the thermostat housing. this one also decomposes. volvo has changed part numbers for this, so they probably kinow they have a problem
--
Wayne
--
Tom 69-1800S, 72-1800ES, 96-850T






THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD

New CRAKCASE PRESSURE [850]
posted by  someone claiming to be JOE  on Mon Sep 22 02:34 CST 2003 >


<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.