Transmission?

what would cause this cars idle to race, the rpms to rev up to about 4, barely move then work perfect;y fine the next day? this problem occurred before and i was told to get the transmission replaced, so it was however it is a rebuilt one. the car only has about 67,000 miles on it so i would expect it to last a bit longer. anyway, i cannot figure out what is going on with it perhaps you can help?

need more information. Such as make year model.

1994 ford escort

Is it really racing in idle, or do you mean to say that the engine revs to 4K when you press the gas pedal, but the car barely moves?

I’d be worried about a possessed car if the engine can go to 4K in idle (idle = foot off gas pedal).
If this is happening in gear, foot on gas, and car barely moving, then it’s a transmission or clutch issue. (Transmission if you have an automatic, clutch or transmission if you have a manual, but probably clutch.)

oh it races in idle and when i press on the gas to try to kick it down it sometimes will idle faster. most times when i put it in drive it will right itsself. the rpms though, that would happen with my foot on the gas, and it will barely move. but today, and yesterday apparently it is running fine.

A 16 year old car with 67K miles is driven infrequently and/or very short distances. The yearly mileage is less than 5,000 a year.

When was the transmission replaced, years and miles ago?

What service and maintenance does the car get?

Can you be more specific about the symptoms. For instance is the car in neutral when the idle is at 4K? Is the car in drive or reverse with your foot firmly on the brake? A car that idles at 4K when you are in drive is dangerous. Is this something that has happened when you start the car up cold, or does it happen when the car is warmed up?

With the info so far we can’t really help you because it just isn’t clear what is going on.

Before thinking about another transmission have someone check and perhaps lube the cable from the gas petal to the motor. It is an old car and perhaps things just need a shot of oil or lubricant in the right place. Take the car to a mechanic and have the throttle cable checked out. It could also be sticking in the throttle body, which is the part the feeds gas to the cylinders in the motor.

Shouldn’t be a big deal, but it doesn’t sound safe to drive as it is now.

I’m still struggling with what you’re trying to describe. Take two things and separate them. First, does the engine sometimes race at idle? I.e., you are sitting still in the car with the transmission in park (? - we still aren’t sure its an automatic of not) and your foot is not on the gas, but the engine is racing at 4000 rpm. Is that right? But this only happens sometimes?

Second, sometimes you put it in gear and the car won’t move? The engine will rev up, but the car doesn’t go? If so, does this only happen when the idle is acting funny? Or can this happen no matter what the idle is doing?

But then, sometimes you get in the car and everything is perfectly normal? The engine doesn’t race and the car moves fine when you put it in gear and press on the gas?

sorry, i am having a hard time figuring out how to tell you. so i will try again, thanks for being patient. i turn on my car and sometimes the idle in the park position after turning the key, is very high,the rpms are high say 2. then i put it in drive and usually it goes to normal idle. otherwise i turn it off completely and turn it on again and it runs fine. about a month or 2 ago i will have to check my records, took my car in because after coming to a complete stop and stepping on the accelerator, the rpms would increase but the car would barely move. so i supposed that it was the transmission. had it replaced about 2 months ago and now the same problem is occurring. so i had it towed back to a different mechanic and the driving it the next day, they say the car is driving just fine. so now i am extremely confused. and do not know if i should just junk the car or try to save it. i didn’t want to bring it back to the place that put the rebuilt transmission in because twice i paid for labor and have the same result. am i explaining this any better?

What did you pay twice for labor for? Did they have to put two transmissions in it?

Are either of the shops that you took it to shops that specialize in transmissions? You need a local and independent transmission shop - not a national chain transmission shop and not a general purpose mechanic. A local person who mostly does transmission work.

Take it there and explain what is going on. The transmission does not operate all by itself. How it behaves depends on information that it gets from the engine’s computer. If the transmission acts like it slipping one day and then is perfectly fine the next day, then it sounds to me like you might be having an intermittent fault in some aspect of the engine’s management system and perhaps one that interfaces with the transmission controls. One of the things that comes to my mind would be a squirrely throttle position sensor (TPS) since its signal is used as part of controlling fluid pressure in shifts. But that’s a complete WAG - just an example of a thing that affects both what the engine & transmission do.

Anyway, a good, local transmission shop should be able to hook it up to a scanner and watch what info is being shipped back and forth between engine & transmission controls, and what is going on with transmission controls.

The occasional high idle might be wrapped up in that - or it could be a separate issue, maybe with a sticky idle air control valve.

yes a transmission was put in twice. i am trusting that they put in two different ones but… so anyway what you are saying is take it to midas. thanks for your help.

Okay, 2K is different than 4K. At 2K RPM it is possible that your IAC is dirty and sticking. You can clean it and probably be okay for another six months, or you could replace it. This only helps with your racing idle problem.

It is not related to your other, bigger, “barely move” problem. That’s the transmission or the transmission fluid level I suspect. You might also check the gear shift linkage.

Actually, he specifically said not to take it to Midas. “You need a local and independent transmission shop - not a national chain transmission shop…”

I also advise you to stay as far away from Midas and the other chain transmission shops as you can.

Opps, you had Midas replace 2 transmissions? Since the car is driven so few miles you haven’t driven either of the new transmissions much. Did you tell Midas to put in the transmission, or did you take to them and they tested the car and they told you it needed a new transmission?

Midas is not where I would go for major work on my cars, and replacing a transmission is major work. They can do mufflers and perhaps brakes, but I won’t trust them for much more than that. You need to take the car to an independant transmission specialty shop (not a chain - not AAMCO, not Cotman, etc.) and have the transmission job checked out.

Perhaps the transmission is fine and it is just the cold start part of the motor that is acting up, but I would double check the work done by Midas.