What would cause my cars rpm to drop when driving around 55mph?

Asked by Nov 18, 2015 at 08:42 AM about the 2006 Pontiac Grand Prix

Question type: Maintenance & Repair

While driving, when I hit around 55 mph my
rpm will suddenly drop down for a split
second then resumes as normal. At least
that's how it started, then one day while
driving my rpm just dropped and lost all
power and will not start back up. It has a
clicking while trying to start it but it will not
turn over.

5 Answers

109,735

See if you can have the car read for any codes to help see what the issue may be...

2 of 2 people found this helpful.

They did a diagnostic on it but not sure about the codes. They're saying it's the pcn computer?

Just really frustrated, it's been broke down for about a month now. I feel like I'm getting the run around. First they told me it was just the computer and now it's the pcn computer. Is there a difference? And would that mess with the rpm? I don't remember no warning lights coming on when it lost power while driving down the road. It still had lights on in the vehicle,but would just click and not start.

76,955

It may be a fuel supply problem but it also could be lack of spark. You may need to replace the fuel filter.

4,275

Do you have an actual shop working on your car? A competent repair shop will check for codes, tell you what they found and what they mean and give you some sort of a price estimate or quote on what the repair will cost. If that's not what you're getting I'd suggest trying a different shop. I could be a lot of things. Don't start throwing parts at it hoping for a miracle. Spend a few dollars on some proper diagnostics.

1 of 1 people found this helpful.

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