Need help! Have a 04 Mazda 3 ,2.3L AutoMatic, 75k miles
been having intermittant hard shifts from 1 to 2. so this weekend so I checked trans fluid. A little low so I topped it off...maybe 1/2 liter. Also changed motor oil while I was down there. Now drove it around the block and lots of white smoke coming from the exhaust. Read some threads with similar results. They say the oil was overfilled. It was was at the high mark so I drained a little out. That didn,t fix it. The smoke smells like the AT fluid and some threads indicate that the AT modulator valve has a vacuum leak. This appears to the best bet .....Where in the heck is it. It doesn't appear to be external. Is it within the drain pan? I also tried looking for a replacement part so I can have an idea how it looks and how to replace it. No luck for 04. A few for older years. Any ideas?

 

trans issues are not going to cause white smoke out of the exhaust, an overfill of oil will or antifreeze, how did u check your oil, u do know that the car has to be on a level surface and the engine warm to the touch, remove dipstick, wipe, insert into engine, and pull out again to check level.

There isnt a vacuum operated anything on our trans, its mechanical, electrical and hydraulic, when u add fluid make sure its the proper type which is NOT Mercon. Ask your dealer for the correct type, better yet just buy it from them, if they tell you mercon is ok dont listen just buy what they got and leave. Mercon is ford's trans fluid not for use in the mazda, incorrect fluid can result in weird shifting and premature failure

 

Thanks tracker for the reply...
I replaced the oil with a heavier oil , 10/30W and added an oil leak addtivie and it fixed the problem. This was probably an overkill but I was really scared due to the smoke issue. Never seen that in the many years of changing my oil. Most likely it was an oil overfill situation. Also it is good to know this model does not have the transmission vacuum modulator valve.

Thanks

 

didnt mean to sound like an a-hole explaining on how to check and add oil, but now a-days you have to explain it to people

 

Normally white smoke out the exhaust means a blown head gasket and antifreeze is leaking into a cylinder. A good indication of this is white foam on your oil dip stick.

virg

 

the reason why i didnt say a head gasket is because he didnt say it was overheating and needed to add antifreeze, so that pretty much ruled that out, but i did jump the gun in assuming that it was oil, no idea what i was thinking, white smoke=burning antifrezze, blueish smoke=oil