99 lumina transmission problems

[pairof97blazers]

99 lumina, when first started, transmission will go into gear and i can move the car, but after about 3 or 4 minutes, it will not move the car at all. any thoughts as to whats wrong, a bit more specific than Trannys toast please

[maxwedge]

Well without seeing what may be laying in the bottom of the pan and/or doing a pressure test what would you like to hear, you certainly have an overhaul ahead of you!

[FishFind]

check fluid level and color

[pairof97blazers]

fluid level is just under full mark, a little dark but still has reddish tint (full flush 50 k ago) no burnt smell, sounds like the pump is cavitating. im gonna change the filter tomorrow and see whats going on. Stay posted for PICS

[jeffcoslacker]

Usually means the pump is shot, or a seal is blown so badly that it only gets enough fluid pressure to operate when the fluid is cold and heavy....once it warms, fluid weight drops and pressure goes below threshold to operate correctly...

[dimperdoo]

my '98 does this exact same thing - bump...

[maxwedge]

Welcome AF. Ok, so the above advice applies to you but as you see there is no response as to the resolution.

[dimperdoo]

Is there an aftermarket, handheld code reader I can pick up reasonably that will read the transmission codes?

kind of a trick getting the car from my rural location to a shop.

Just confusing w/ this issue because the transmission does work normally for the few minutes after you start the car -and, it will do it again if you turn it off and start it again - lol

[maxwedge]

Pcodes for the trans usually show up with a normal high line scanner, for diagnostics you need a real professional scanner.

[dimperdoo]

what about this one: http://www.obd-home.com/obd2-can-bus...480-p-379.html

[maxwedge]

That will read basic codes, not much chance you will get tanas codes unless the cel is on, very basic unit.

[Tech II]

There are some good deals on low end scanners(that also read engine data, as well as read/clear codes, check flags) at Amazon.com........

[dimperdoo]

OK, so what I have now is a "snap-on diagnostics scanner mt2500"

I hooked it up and, it said the car was "ok to drive" lol

Don't know much about what I'm looking for but one thing I did notice was trans fluid volume was @ ~2.4 while the transmission worked but, was @ 1.99 when the tranny stopped working. still "ok to drive"

[maxwedge]

I seem to remember the MT2500 had an accessory trans cartridge for bi-directional diagnostics, the scanner cannot tell all, slipping is slipping something diagnosed during a road test.

[dimperdoo]

is the fluid volume info significant though?

I guess my next step is to pull the pan and see what the fluid looks like/if there's debris in the pan...