D.Stillwell

Hello to all! So I've been trying to diagnose this problem recently. My tranny breather hose spits a tiny bit of fluid here and there, seems to be only when I drive the car hard and go WOT. The amount it spits is very little, just like a drop right on top of my snorkel from time to time. This is on a VQ30DEK 4AT w/ 81k miles.

This problem surfaced after I had a slowly building exhaust leak for some time, which also caused blockage right before it finally broke about a week ago (pipe broke at the rear muffler to mid-pipe connection, moved and blocked the opening on the mid-pipe causing lots of back-pressure to the engine). The back-pressure that resulted from this caused my intake breather hose to leak blow-by from the valve cover connection as it just seeped from under the hose between the nipple from all the pressure, as well as the coolant hose connection just forward of the coolant temp sensor).
The exhaust is now all fixed, car runs well w/ no problems, and there is no more back-pressure causing leaks from any hose connections (at least not that I could find and I did testing on all the hoses and vacuum lines).

Now my problem is this high pressure building in the tranny. And I'm almost 100% sure that this was caused by the recent back-pressure in the engine as all this clearly surfaced right after. The trans fluid level is good, it's not overfilled, the transfer case is good and not overfilled with no leaks, and there are no leaks that I could find anymore, there is no more back-pressure so at this point I know the pressure is building inside the tranny and spitting out the vent hose just when it's driven hard.
In the past few days I noticed that after a "spirited" drive the pressure will be so high in the trans, that when I go to put the car in park it feels almost like a 3rd-4th shift at WOT. The tranny itself shifts butter smooth, it's just this pressure issue, and it's making the car shift like a manual (in a good way) when driven hard. It almost feels like there's no dropping resistor anymore when driven hard and it's shifting at full pressure.

This is making me crazy, because I've done pressure tests all over the place, vacuum lines, etc, etc. And didn't find any problems there, the pressure seems to be ONLY inside the tranny itself.
I'm thinking my problem is likely a bad PCS, which would've went bad from the back-pressure I had. What do you guys think?

It does NOT seem like it's getting overheated, and my coolant temp sensor is working fine. Also, my oil pressure switch seems to have developed a problem after the back-pressure issue as well, I now have the blinking oil light on start up for 2-3 secs.
Sorry for such a loooong post, I hope someone has seen this problem before and it's just something simple like a pressure sensor and not more serious.

I thank you all for reading and appreciate any and all help, this is driving me nuts and I know this is not gonna be good for my trans to keep driving it while its shifting at full-pressure, so I'm trying to fix it ASAP.

JWatZ

iTrader: (5)

Probably have, but have you checked that drop resistor? The talk about pressure and how it's shifting sounds like mine when I flip the switch (have done the dr mod to a simple missile switch). Maybe check the voltage to it.

MAXC

iTrader: (7)

The problem you were having with back pressure has nothing to do with the tranny. The tranny is completely isolated from that issue. If your tranny fluid is getting that hot then you may want to look into an external tranny cooler. You say the fluid level is correct, but I do know that a overfilled tranny will sometimes spit fluid out the breather tube when its boiling. Does it do it on regular day to day driving or just when you drive it hard. I'm some what horrible with abbreviations but what's a PCS?

NmexMAX

iTrader: (22)

Just a question, but how do you know it's filled to the correct level, the ATF? Got any pics of the breather where it's spitting and you're certain it's ATF?

As far as the oil light blinking, how's the oil level?

What's a PCS?