Automatic transmission issue

2000 Mazda Millenium: automatic transmission either will not, or with extreme hesitation shift out of low gear when car is cold… shifts normally after car runs for a while. shifting manually sometimes helps the process, but only so slightly.

Have you checked the level and condition of the transmission fluid? That is the first step. Checking condition means color & smell - it should be red - if it is brown your trans probably really needs service. If it is black & smells burned, that means your trans has overheated at some point & should be checked out by a specialty shop.

Anyway, the hesitation may just be from low fluid. But if you find it low that means you are leaking some and also need someone to look at it.

This problem won’t fix itself and could get worse. You may have too much fluid in the transmission but I doubt it these days. I think you will have to rebuild it.

The fluid was changed several years back by my mechanic of over 20 years so I assume it is not a fluid issue. He has recently seen the vehicle, but can not solve the problem. I have been advised that most transmission speciality shops are border-line legit and that nowadays dealers basically replace all instead of attempting repair. Thanks for your input

thanks (see response to other comment)

I would just advise you to explicitly double check that your mechanic checked the fluid level. I’ll assume that s/he did, but I have no idea why having had the fluid “changed several years back” would reassure you that the fluid level & condition isn’t a problem. You could change the fluid today and have a problem with it tomorrow. How many miles have you been in those several years? B/c you’re likely due for another service on the trans. I am not suggesting that this will solve the problem - just saying that several years between trans service is a lot.

That is not a sufficient reason to assume fluid isn’t the issue. Assume it is the issue until you have ruled it out.