850 glt breather leaking oil bad

fred54321 · Post by **fred54321** » 09 Sep 2006, 08:05

what does the breather do ???.and if clogged up is result lose of power etc.
think its known as oil trap???can oil trap just be cleaned or is it best to replace are they exspensive???PCV

stoutlogic · Post by **stoutlogic** » 09 Sep 2006, 18:26

Oil trap, breather, flame trap (Volvo specific term) and PVC are commonly used terms/ parts that basicaly allow for the engine to vent positive crankcase pressures due to blow by from the pistons.

If the engine can't vent you can experience:

oil dipstick and oil blowing back out the top of the dipstick hole

leaking main seals, cam seals

smoke from the tailpipe

dipstick or dipstick tube with rust or milky white substance which is a mixture of oil and water

If car is a turbo you have an oil trap other wise you're in the market for

Post by **pfeener** » 09 Sep 2006, 20:23

Here's the deal as far as PCV (Positive Cranckcase Ventilation) systems are concerned:

Any engine, not just Volvos, will create pressure in the crankcase, due to blowby of the piston rings. The PCVs job is to remove this pressure so it doesn't harm the seals in your engine. Prior to the 1960s, engine crankcases were just vented out to the open air with a mesh type screen covering the breather tube. Worked fine, but the EPA didn't like it much. After 1960 or so, PCV systems came into being. The PCV system uses engine vacuum to remove cranckcase pressure and actually create a vacuum within the engines crankcase. The cranckcase gasses are sucked back into the intake manifold and burned in the engine's combustion chamber. That's the generic information. Volvo's however have a very different type of PCV system, but the end result is as discribed above.

To test your Volvo's PCV system, remove the dipstick with the engine running and see if it puffs out smoke which indicates positive pressure in the crankcase. If the PCV system is failing you need to rebuild it. FCPgroton sells all the parts in a kit. Here's the link for a non-turbp 850:

http://www.fcpgroton.com/volvo850oiltrap.htm

fred54321 · Post by **fred54321** » 10 Sep 2006, 12:22

were place to but pcv oil traps im in uk

Post by **pfeener** » 10 Sep 2006, 12:45

FCP will ship to the UK or you can order the parts from a Volvo dealer.

Volgrrr · Post by **Volgrrr** » 16 Sep 2006, 17:15

I'm in Australia and often use FCP Groton to source parts for my 850.

I find FCP Groton are always very competitive (price wise) and provide a very quick delivery service.

From my own experience I believe you can use FCP Groton with absolute confidence.

Post by **Pauloil** » 19 Nov 2006, 07:18

it may be normal to see a little smoke form dipstick

Post by **MadeInJapan** » 19 Nov 2006, 08:32

Normal? To a certain degree only after starting, but it shouldn't be spewing smoke after it's been running for a few minutes. After the car warms it, there should definitely be a vacuum from there. If you put your finger over the hole, it should be pulling on it slightly, not pushing it out. Same thing goes for the oil fill hole at the top of the engine, when you remove the cap.

RobV · Post by **RobV** » 17 Feb 2007, 11:18

MadeInJapan wrote:Normal? To a certain degree only after starting, but it shouldn't be spewing smoke after it's been running for a few minutes. After the car warms it, there should definitely be a vacuum from there. If you put your finger over the hole, it should be pulling on it slightly, not pushing it out. Same thing goes for the oil fill hole at the top of the engine, when you remove the cap.

It should be like that but my 2.5 non turbo 850 1994 seems to spew smoke out of dipstick tube. I checked PVC, exchanged flametrap (it was clogged) and change the oil separator for brand new( it was clogged at the lower connection to engin). No effect. I mesured the compression and it was +/- 180 180 180 180 180 with the milage of 150k miles. The comression seems to be at the low end of factory specs. So where this positive pressure comes from? It seems no excessive blow by is present (high and even compression)

Post by **MadeInJapan** » 17 Feb 2007, 13:18

I would check the bayonette connection att the lower end of the accordian type air hose (from air filter box) to either turbo or throttle body if all else is clear. This is where the hose connects to a heated valve. It gets clogged very easily and most don't know that you can take it off, run a pipe cleaner or two in to it with alcohol or throttle body cleaner to clean it.