auto transmission leak mystery

[ebiv2003]

2003 FWD auto tranny, 148,000 miles, tranny fuild changed at 100k
couple weeks ago rough shifting noticed, check dipstik low fluid, add two quarts, shifting improves but after few days fluid level dropping again, do usual cardboard under car drip leak test and visual inspection. no leak detected.
Take car to toyota non dealer shop, they cannot find any leak source from tranny, now the story gets real weird....
they find 2 qts overfill in engine crankcase. Their solution; do engine oil and filter change watch engine and tranny dipstiks for a week.

so has anyone ever heard of tranny fluid migtrating into engine?
mechanic says no way this can happen and i tend to agree but what we are seeing cannot be disputed?

[Chiadog]

Perfect post for April Fools' day! And I once owned a Farmall tractor that did this, but in reverse - bad rear main seal.
This however, from my knowledge of the Vibe seems impossible. Some Japanese auto trans did loose oil thru theur vacuum kick-down switches:
"JATCO stands for Japanese Automatic Transmission Company. JATCO was a joint venture between Nissan and Mazda, both owning 50%. The JATCO unit is very similar to a Ford C4 and almost bulletproof, the only thing that seems to go wrong with them is that (rarely) vacuum modulator diaphram ruptures and ATF gets sucked into the intake manifold,"
http://datsun1200.com/modules/mediawiki ... ansmission" onclick="window.open(this.href);return false;

Does anyone know if the 2003 Vibe has a direct connection of engine vacuum to ATF oil?

[Chiadog]

Did you ever find the problem, ebiv?

[joatmon]

Don't know if a similar thing exists in the auto tranny Vibes, but my first car, a 69 Dodge Coronet had some sort of vacuum activated shift solenoid, perhaps something to keep the tranny from shifting up at full throttle, not really sure what the purpose of it was, but at some point the diaphragm in it tore, and engine vacuum sucked tranny fluid into the engine. Had similar symptoms of losing tranny fluid but no leak, the engine oil quite overfilled and slightly reddish in color.

[lannvouivre]

Did you change it, or did a quick lube place do it? I don't think there's any way the ATF could be migrating in. Maybe you can try using the Valvoline ATF; it has a very distinctive and strong smell, so you could probably smell it if it was getting into the engine oil. Do you let the car warm up, shift through all of the gears, and check the dipstick while the engine is running?

Sorry if any of that is offensive, I have no idea what mechanical experience you may have.

[Salsa Guy]

Check your coolant for tranny fluid. It could be leaking in the radiator/tranny cooler.