PCV system question

Ricardo · Post by **Ricardo** » 13 Mar 2011, 06:55

I have recently purchased a 1995 volvo 850 turbo wagon and have done all the stage 0 items except the pcv system. I do have an extensive repair history on this vehicle and it shows a "flame trap service" that was done 50k ago ( car itself has 327k

). The charge was 350.00 so I will ASSume this was the pcv service. With that being said, I did notice a small amount of oil under the plastic spark plug cover. I have read all the posts and this huge fear of blowing a rear main seal. I have read that pulling the oil dipstick out about an inch will help vent the crankcase. I noticed after driving it hard that oil had come out of the dipstick and ran down the outside of the tube. Any thoughts on if this would be normal to occur? Or is this also an indicator that the pcv system needs serviced. I spoke to a mechanic at the Volvo dealership who said to start the car and unscrew the oil cap but don't lift it off. He stated that if the pcv was bad the oil cap would bounce up and down on the cover (which it did not). I would think if the system were clogged that all the pressure would be in the lower end of the motor.

Post by **jblackburn** » 13 Mar 2011, 07:01

That's a common place for oil to leak - sometimes it just means that your oil cap needs a new rubber gasket on it.

Look at the Youtube video in this post for a simple check you can do to tell whether or not the system is in need of a cleaning.

https://www.matthewsvolvosite.com/forums ... =1&t=28487

It probably was serviced (it'd have to have been done at some point for the car to have made it to that mileage), but a Turbo model doesn't have a flame trap

Ricardo · Post by **Ricardo** » 13 Mar 2011, 07:04

jblackburn wrote:That's a common place for oil to leak - sometimes it just means that your oil cap needs a new rubber gasket on it.

Look at the Youtube video in this post for a simple check you can do to tell whether or not the system is in need of a cleaning.

https://www.matthewsvolvosite.com/forums ... =1&t=28487

It probably was serviced (it'd have to have been done at some point for the car to have made it to that mileage), but a Turbo model doesn't have a flame trap

What are your thoughts on the oil coming out of the dipstick though?

Post by **jblackburn** » 13 Mar 2011, 07:18

A heavy foot can do that. That may indicate that there is some positive pressure.

Pull out the oil dipstick and check for smoke. Then with your other hand, rev the throttle a bit and see if it continues smoking.

MA Volvo · Post by **MA Volvo** » 13 Mar 2011, 07:56

I have a 97-850 Turbo with 180K miles and I am new to this site. I am in the middle of replacing the PCV parts. I will be taking the intake manifold of later today.

In addition to having oil vapors rising from the dipstick tube A LOT of oil has pooled in the wells on top of the Al valve head cover. I ran the car with the dipstick pulled out an inch and the oil cap loose which significantly reduced oil loss.

Is this oil pooling indicative of any type of blown seal? If so, how involved is the repair?

Post by **jblackburn** » 13 Mar 2011, 08:18

It doesn't sound like yours has blown a seal yet; just that the system needs to be cleaned. If the cam seals let go, they will gush oil EVERYWHERE out the side of your engine; the RMS will probably leak onto your driveway.

Sounds good that you're getting your system cleaned out - make sure you clean the ports on the engine block out thoroughly with a wire brush/some type of solvent.

MA Volvo · Post by **MA Volvo** » 13 Mar 2011, 08:48

Thank you for the quick reply. I will document my experience and post pic and/or videos.

The spark plug wires have an oil sheen on them. Do you think that this amount of oil could affect affect the performance of the wires and cause a misfire?

Was it likely that the "pooled" oil leak thru the cam seal? Is taking off the cam cover a big job? I bought the liquid gasket.

gilhuly · Post by **gilhuly** » 13 Mar 2011, 09:36

The pooled oil did not come from the cam seal. It came out of the oil fill neck. There is no need for you to take off the cam cover unless cam seals other than rear exhaust seal (closest to steering wheel) are leaking.

MA Volvo · Post by **MA Volvo** » 13 Mar 2011, 10:42

So it sounds like I should I should replace/clean the PVC components, refirbish the cap and rotor and reinstall everything and then monitor for any new oil leaks. Is that right?

gilhuly · Post by **gilhuly** » 13 Mar 2011, 12:50

Yeah, basically. If you haven't replaced the oil fill cap gasket I would do that.