2000 Chevrolet Monte Carlo SS

Reader Question: My 2000 Chevrolet Monte Carlo SS “shudders” when going up hill or accelerating hard. You can let off of the accelerator and ease back on it and it runs fine. My mechanic says that it does not need a tune up but is possibly the valve body on the transmission (he does not do transmissions).

I have talked to a transmission shop (they have not seen the car) – they say possibly the valve body or the PCM.

Will either of these problems show up as a code? Could it possibly be something else? A friend says that some part (less than $100) on the valve covers fixed his when it was doing the same thing – he had also been told the valve body.

I do not want a $1,000 repair if this will not fix the problem. What are the symptoms of a valve body problem vs. a PCM problem?

Thanks for your response.

Robin

Hey Robin,

I would have your mechanic look at your spark plug wires FIRST. A worn out spark plug wire will break down and cause an engine miss, which can feel like transmission trouble. If your spark plug wires are original or have more than 50K miles on them…they are due for a replacement anyway as maintenance.

I usually replace spark plugs at the same time. But if your mechanic already inspected a spark plug, you might be able to just install the wires and see what happens. You can sometimes “power brake” the vehicle with one foot on the brake and the other on the gas to force a weak spark plug wire to break down to prove a spark plug wire is actually the culprit.

If new plug wires did not do the trick, you could have an internal transmission problem with the lock up torque converter. I would talk to your mechanic about servicing the transmission fluid and filter and using an over the counter additive to help eliminate torque converter “chatter”.

If you have not maintained this transmission with periodic filter changes, AND the transmission fluid is black and smells burnt you might do more harm than good servicing the filter.

Talk to your mechanic before you just run out and do something.

Blessings,
Austin Davis