Bad Gas Or a Transmission Problem?

Reader Question Dear Austin,
I have a Oldsmobile Cutlass Ciera with 139,000 miles. The engine is a 4 cylinder. I was recently driving the vehicle, and then when I stopped, the engine shuddered and then shut off.

The vehicle started right up, but then when I put it in drive, it shut off again. I kept starting it several times, and the same thing happened when I tried to put it in drive.

I was finally able to keep the vehicle started by putting it in neutral, rev’ing the engine slightly, then putting the vehicle into drive.

What could be causing this? (Bad gas?) The vehicle also has a slight car transmission leak—would this be the cause?

The next day, I had just finished driving the vehicle for over two hours at speeds over 60 mph. I was attempting to run the gas that I believe is bad out of the vehicle.

I made a stop, and as I slowed down, the vehicle began to shutter, then it died. I did not get an opportunity to drain the tank of the bad gas, and I did put more gas in the vehicle. Please advise.

Thanks,
Ronald J.
*****************************************

Hey Ron,

I’m glad you wrote to me with this problem—it’s one that can really send you down some frustrating (and maybe expensive) false leads if you or your mechanic hasn’t encountered this scenario before.

You have an internal transmission problem; the Torque Converter Lock Up Solenoid is bad. The solenoid engages when you drive over 35 MPH. When it engages, the transmission “locks” the torque converter to help improve fuel economy.

The problem is that your solenoid is not releasing the torque converter when the car slows back down to speeds less than 35 MPH, so basically you are still in 4th gear when you try to stop at a light.

The engine is “locked” to the transmission which is still rev’d in 4th gear, which is what causes the shuttering and shaking when you stop the car. Your transmission is never letting go of the engine.

When you restart the car and put it in Drive again, you are still in 4th gear, so the engine dies. You are having to gun the engine and bring the RPMs up high enough to get the car moving in 4th gear. It is like trying to take off on a 10 speed bike in 10th gear.

The fastest and cheapest workaround is to not use the overdrive gear, just use the D selection. If you do not have just a D selection, ask your mechanic to disconnect the torque converter lock up solenoid. He can quickly and easily do this by disconnecting a few wires under the hood.

You will NOT have the full benefits of the over drive gear, so the fuel mileage on the highway will be poor, but the problem will be corrected…cheaply.

The long term fix is to have a transmission shop replace the torque converter lock up solenoid, which will probably cost you $325 or so. The bad side to this scenario is that since you have high mileage and you already have a transmission leak, there is a big chance that the transmission will need to be overhauled once the shop gets inside the transmission to replace the solenoid.

Rule of thumb – if the solenoid is worn out, everything else inside the transmission probably is too. So before you have a transmission shop tear apart your transmission all over the floor of their shop, decide ahead of time how much of an investment you want to put into your high mileage vehicle.

Have it inspected by your mechanic to determine any other “time bombs” you may be dealing with to get a complete picture of your expenses in keeping the vehicle. Whether or not it’s wise to put the money into the car to maintain it is a personal decision that only you can make.

Please share this with your friends,
Austin Davis