Transmission or something else?

toyota
corolla
transmissions

#1

I have a 95 Corolla w/140k miles. I’ve been experiencing (for several months) what I feel is the start of transmission problems but two mechanics can’t diagnose it since the problem doesn’t occur all the time.



Here’s the problem: I begin to accelerate from a full stop and the car sounds like it’s in the wrong gear. The car moves forward at about 10-15 mph and the engine sounds like it’s trying its hardest. Suddenly the car will jerk forward like it’s finally gotten in the correct gear and pick up speed. This occurs randomly and not frequently. Enough for me to be concerned though.



Two mechanics checked the transmission fluid and found no discoloration or burned smell. My records show a transmission cleaning and fluid change about 20,000 miles ago. I plan on selling the car at the end of the month and want to know if this is a potential transmission problem or could be something less expensive to repair.


#2

What exactly was the transmission “cleaning?” Did you by any chance take it to a quick lube place? They are notorious for suggesting transmission “flushes,” which sounds great and makes you think you’re doing something good for your car, but can stir up debris and cause transmission problems. If a car is not having any symptoms of tranny trouble, it’s a good idea (every 30K or so) to do a transmission service. This involves visually checking the fluid, then a drain/refill and filter change. You should find a reputable transmission shop to look at the car - describe to them everything you described here.


#3

I don’t have my records in front of me right now but I believe that the filter and fluid were changed in the transmission. I’ll check if the transmission was flushed or not. I had it done at my mechanic that I’ve been going to for years and trust. I explained what I was experiencing to the two transmission mechanics (both highly recommended from friends and my mechanic) I took my car to and they couldn’t tell me what the problem is. Granted they only drove it around and looked at the fluid levels, color and smell. The problem isn’t constant and didn’t occur when the mechanics drove it.

I’m wondering that since the fluid looks and smells OK that this could be a problem not related to the transmission but something leading to it.


#4

Imtermittent car problems are a pain. There are other issues in an electronic transmission that can cause the symptoms you’re having. You might want to have it scanned for codes. I think Advanced Auto still does this for free. You didn’t mention that your “check engine” light was on, but it couldn’t hurt to check for codes. The link below might be helpful. It’s technical but gives a good overview of transmission issues.

http://www.aa1car.com/library/2002/us90224.htm


#5

The check engine light has never come on in my car. I keep reading about these “codes” and that they can be scanned. Can you give me some more information about this? Do all cars have this ability to be scanned? Can my mechanic do this or most auto parts stores?


#6

Your mechanic can do it–for a fee. An auto parts store will do it free-of-charge in the hope that you will buy parts from them, but you are not obligated to do so.


#7

OBD stands for On Board Diagnostic system. From the 80’s on computers have existed in cars to monitor various components, including engine, transmission, emissions, etc. The codes indicate a malfunction of a particular system or component. Reading or pulling these codes are vital to diagnose certain problems. Your car may have an older generation OBD system, so it might not be scannable with an OBD II scanner - the most common one now in use. A good mechanic can check your car for any codes. It couldn’t hurt. You might want to still (as tiresome as it sounds) keep looking for a transmission shop that is curious enough about your problem to want to solve it. And you’ll want to describe to them exactly what the car does. And if the car is exhibiting any other odd behavior - even if you don’t think it’s related - tell them.