89 Rodeo Transmission Prob. PLEASE HELP!

I have a 98 Isuzu Rodeo v6. When I drive my car for more than 15-20 min.(and sometimes after an hour), the "automatic" shifting gives out and I must manually shift. As it gives out, the check engine light turns on (and occasionally the check trans. light). When I come home and leave the car off for a few hours., the problem goes away, the check engine light shuts off and the car automatically shifts just fine. If I stay local (within 20 min.) the car works fine. When I drive long distances, the problem comes back. I recently changes the transmission fluid. Same problem. What gives? ....And how expensive will this be to repair?

Sorry for the mix up in the title.

THIS IS A 1998 Isuzu Rodeo V6.

I could be a bad battery or alt (the alt could be over charging). The trannies do weird things with weak electrical systems.

or

it could be the range sensor is dirty (see the faq's for more info).

How many miles on the tranny and did you regularly service it before this last fluid change? How was the fluid changed this time?

Also it's VERY important to make sure they got the right amount of fluid in the tranny - these trannies are not easy to service, most places often UNDER fill them causing issues. This would be one explaination as to why it does fine in the short term driving but develops issues as it heats up - low fluid = heat = burnt transmission.

However, could also be voltage issue; i.e. alternator is VERY common to start issues. But I would have someone recheck the level on that transmission NOW before you do anymore driving - just incase.

sounds like the tranmission is going in to 'limp mode' or 'backup mode', which is what it does when the trans computer senses a problem and it goes into this preprogrammed mode to protect itself. this limp mode activation is usually the result of electrical problems, usually the charging system, usually the alternator (but could be battery, wires, connectors, grounds). but the most common cause is insufficient alternator output, which needs to be within a rather narrow range. the fact that an alternator would work initially and then give problems as it heats up wouldn't be unusual. same for the battery actually.

however, the fact that the CEL is lit means you can get the codes read (for free at some of the bigboxpartsstores). even though the light went out, the code is probably stored waiting to give you the info on what is wrong.

you can often get the alternator tested in such stores if you want to take it off for that; but be warned, reports are numerous that they often aren't spot on in detecting bad isuzu alternators. also, if/when you go to buy an alternator, you want to stay away from the bigboxpartsstore rebuilt alternators and go with the dealer or rebuilt by bosch (my favorite) and some say NAPA.

the mode switch problem, in my research and my experience, generally shows itself in the form of harsh shifting and engagement.

anyway...my suggestion is start with the diagnostic code reading and check on back with the info.

P.S. any other symptoms of bad alternator, like several dash idiot lights lit up?

//bc

Thanks for all of your replies. I will take it to get checked out. Incidentally, the ABS light is on also (and has been on for a while). I brought it to a local mechanic and he could not figure out what was wrong. I assume it is related to a recall issue. I will bring this car to the dealer to fix and hopefully they can give me more info on the shift situation also.

Sure sounding more and more like the alternator failing; these trucks will throw up strange idiot lights when their volts are weak.

....the ABS light is on also (and has been on for a while).
yes, more evidence of charging system problems. the addition of the ABS light may lean towards a ground, or battery cable problem. could be as simple as cleaning and tightening the battery terminals.

... I assume it is related to a recall issue. why do you assume that? and what recall isssue are you referring to?

//bc

sounds like force motor solenoid

they usually start to stick if tranny trash gets stuck in them usually caused by not changing tranny fluid out often enough

Thanks again for all of your help. This list is invaluable. This information helps keep an 'everyday' guy like me (who knows next to nothing) from getting ripped off. I will check out each of these leads. I'm taking the truck in next week. Also ,if there are any more ideas, feel free to post them. Ill be checking back regularly.

Peter

P.S. Trooperbc- I'm probably wrong about an ABS recall. I thought that I read about it somewhere, but I never actually researched it.

vehicle may fall under recall for the abs module but the most likely cause for the light being on would be broken wire or wires at the abs connecto right above th left rear wheeel at the frame of your truck