PCV Pressure

hrm · Post by **hrm** » 22 Jul 2008, 15:18

so far I have changed the PCV system including the oil separator, Cleaned the PTC and replaced the oil cap gasket.

I am still having obvious oil vapor come from the dipstick and oil under the cam cover - is there something I'm missing as far as reducing the pressure or is there something that still might be clogged causing the increased pcv pressure?

I think this whole thing has ruined my rear main seal, but it's hard to tell if it's ruined or if the pressure is still forcing oil out of the seal, and if i fixed the PCV pressure the seal might still be good.

Any ideas would be greatly helpful. Thanks

Post by **JRL** » 22 Jul 2008, 15:23

Pressure should be 0 (can be measured)
You may still have clogs somewhere
Why don't you SEAFOAM the car to get rid of all the carbon and crud buildup?

chuckcintron · Post by **chuckcintron** » 22 Jul 2008, 18:02

+1 on the seafoam tip.

Also, read this thread. I had the same issue you are having. Double check that PTC; it needs to be as clean as when it came off the assembly line.

https://www.matthewsvolvosite.com/chat/p ... hp?t=15475

-Chuck

Post by **JRL** » 22 Jul 2008, 18:06

chuckcintron wrote:+1 on the seafoam tip.

Also, read this thread. I had the same issue you are having. Double check that PTC; it needs to be as clean as when it came off the assembly line.

https://www.matthewsvolvosite.com/chat/p ... hp?t=15475

-Chuck

Do you mean PVC

Post by **MadeInJapan** » 22 Jul 2008, 18:25

No Jim, the PCV is the entire system...the PTC is the nipple on the air intake (accordion) hose- an orifice that is often clogged and overlooked- a part of the PCV system of hoses.

Post by **JRL** » 22 Jul 2008, 21:27

MadeInJapan wrote:No Jim, the PCV is the entire system...the PTC is the nipple on the air intake (accordion) hose- an orifice that is often clogged and overlooked- a part of the PCV system of hoses.

Is that what's it's called?

I call it the nipple and I check and/or clean it if need be on every car I have

Post by **MadeInJapan** » 22 Jul 2008, 22:06

Yeah, it's important but a PITA to get to so a lot of techs just don't bother with it- a big mistake!

Post by **holler1** » 22 Jul 2008, 22:49

PITA is right. I removed the accordion hose today on my 98 V70 AWD to clean the PTC as a first step in cleaning the PCV. I cleaned the PTC with some carb cleaner. I haven't tried to put back on but expect a PITA there too because I can only get one hand near the bottom of the turbo. Also found and fixed what I hope is the last vacuum leak- large hose on top of the evap canister. I put some seafoam in the crankcase yesterday as well as down the hose from the top of the engine that goes into the oil trap. I was hoping it would fix the positive pressure from the oil dipstick, but so far no luck on that after running the engine about 1/2 hr. Will seafoam in the vac system help clean the PCV? I haven't tried that yet.

Post by **MadeInJapan** » 23 Jul 2008, 05:00

Never heard of Seafoam in the Evap. system (are we talking about the lines from the gas tank to the front of the car which is the Evap. system?). It could screw things up. Let's wait for other answers.

chuckcintron · Post by **chuckcintron** » 23 Jul 2008, 06:16

On that PTC (nipple) removal: If you're lucky enough that the hose clamp on the accordion on the intake side of the turbo is oriented so the screw head is facing UP, then loosening that clamp with a 20" flat blade screwdriver makes the job very easy.

I also tilt the hood up to vertical (release the stoppers), and I kneel on the radiator top cross-beam when I do this. Really, it makes a formerly PITA procedure a piece of cake.

Chemically cleaning this thing is usually NOT enough, unless it really comes out spot-free. The copper walls of the PTC need to be cleaned and the tiny hole at the bottom of the larger opening has to be completely opened up. I had to use a coathanger to ream it, and steel wool on the inside walls.

Dave, I think holler1 was talking about pouring some seafoam down into the oil breather (PCV) box...not evap. That's fine. It won't help anything, but it's ok.

Finally, if you are still getting positive pressure out of the dipstick, the spot to check is the port on the block that sits up higher, near the top of the PCV oil breather. That port has an internal path to the sump. Ream it out with a coathanger, then find a nice big nylon wire tie and use that. Then, blow into it with 100PSI of compressed air. If you do that you should feel a good stream of air coming out of the dipstick tube. If you get that, and once put back together you are pulling a good vacuum back out of the top of the breather box (back to our friend the PTC), then you should have neutral or negative pressure at the dipstick.

-Chuck