99 Cross Country with positive pressure after PCV system replacement

T64me · Post by **T64me** » 30 Dec 2016, 09:48

Hi everyone,

I'm trying to help out a friend that has a 99 Cross Country. He purchased this car and it sat for a few years before he had the cylinder head rebuilt (it had a burnt valve). As he was replacing removing/replacing the cylinder head, he replaced the PCV system. He still has issues with positive pressure so he:
- Cleaned the ports in the engine block behind the PCV oil trap. He can run pipe cleaner in them and says they show fresh oil from the pan when he pulls them out.
- The PTC nipple (PCV line that attaches on the air intake) has also been replaced

Still, the oil dipstick blows out of the tube.

The biggest bummer of this is that my friend's son zip-tied the dipstick tube down and the pressure caused the cam seal behind the variable timing gear to blow. Getting the timing set right on this car was a pain, so having to pull that variable gear to replace the seal is not high on anyone's list of things to do...

Given what has been done to the car, what could be causing the positive pressure?

Thanks in advance for your constructive input!!!

Post by **bmdubya1198** » 30 Dec 2016, 10:06

Hmm... do you know that the hoses are connected in the right places on the oil trap? And did he replace all of the PCV hoses? Seems odd that after replacing the system there is still positive crankcase pressure. Clearly it isn't an issue of the dipstick not fitting correctly since the car blew out a cam seal with it tied down.
Resetting the timing on the VVT cam isn't too bad... definitely tedious though. I can see it being a major pain in the you-know-what without a cam locking tool. Just make sure everything is aligned properly when the gear is turned forward in the loaded position. And MAKE SURE YOU PRELOAD THE GEAR. Bad things happen when you don't do that... ask me how I know.

Post by **erikv11** » 30 Dec 2016, 10:34

How is the compression? Free to check, definitely worth knowing. Could be one of those rare white blocks that has developed significant blowby.

Also +1 on the order of the hoses on the oil trap, that matters and is easy to mess up.

Post by **abscate** » 30 Dec 2016, 15:38

There is an internal portal in the block that can plug if the PCV is really dirty. It needs to be open to vent pressure

Post by **erikv11** » 30 Dec 2016, 18:04

T64me wrote: ...- Cleaned the ports in the engine block behind the PCV oil trap. He can run pipe cleaner in them and says they show fresh oil from the pan when he pulls them out. ...

We seem to have more cases today of posting without reading the threads ... I've been guilty of that!

Post by **abscate** » 30 Dec 2016, 18:17

Ouch - guilty as charged - missed that one.

PeteB · Post by **PeteB** » 01 Jan 2017, 09:21

The small vac connector on the top of the flame trap was plugged on our car,
open it up with a 1/16" drill bit. This is important for flow at idle.

Post by **erikv11** » 01 Jan 2017, 18:04

It's a turbo car, so the plumbing is a little different. There is no flame trap.