Car Slows When Foot on Gas

toyota
camry

#1

When I am driving along in my 2000 Toyota Camry 6 cylinder, and my foot is on the gas, my car slows down by itself. When this happens it sounds like gears are changing or like when you run out of gas, (the car is automatic and the gas tank full). After this happens the car speeds up again. All without any help from me. It this a serious problem?


#2

Lots of things can cause this - some “serious” and some less so.

Is the check engine light on? If so then you need to have the error codes read and post the exact codes. If it’s not on, it should come on sometime soon.

How many miles are on it? Can you give a basic run-down of maintenance items? How old are your spark plugs and wires? Fuel & air filters?

If you have check engine light at the moment, you symptoms are too vague for people to guess by internet. Someone who knows about cars will need to drive it, preferably with a scantool attached.


#3

The check engine light is not on. The mileage is low, about 40,000. The maintenance is not great. Perhaps I should get those things check. I only go to the mechanic when something goes wrong and the car runs well with the exception of slowing down. I guess I need to take it in. As you can see by the mileage, it is not driven that much.


#4

Yes - you need to take it in. Pull out the owner’s manual and look up the maintenance schedule. Note that most maintenance items are given by miles OR time - whichever comes first. You will most typically be going by time and most of your basic maintenance items are probably overdue.

What you want is a reputable locally owned and operated shop - not an “auto care” corporate chain shop. Those places are set up to sell you stuff rather than to help you keep your car in order. Take it to them, explain what is happening with car and that you haven’t really dealt with maintenance very much. Ask them to advise and help you make a plan to spread out the costs of getting back up to date over time if need be.


#5

All good comments above. Bringing all the routine maintenance suggested in the owners manual up to date is the first priority. Having the codes read would be next. Just b/c the check engine light isn’t on doesn’t mean there are no codes stored. For the most part the check engine light comes on only for emissions problems. Between updating the maintenance and reading the stoed diagnostic codes, that would likely put your mechanic well on the way to a fix. If not, I think if it was my car I’d hook a fuel pressure gauge up to the rail and watch it while this symptom is occurring. If the fuel pressure is dropping unexpectedly in synchrony with the slowing down, that would provide enough of a clue to find what is wrong. And if it didn’t drop, at least you’d know it wasn’t the fuel pump or pressure regulator causing the problem.


#6

Not many miles but the car is old. First guess is then a fuel system problem…old gas at some point or filter or pump.


#7

All good comments here. I will add one more…when my Dodge Dakota started to act like this I drove directly to a large auto parts store and bought a TPS (Throttle Position Sensor) and installed it. You may have a more serious problem but the TPS is inexpensive and is easily changed. I haven’t had the problem since.


#8

This is happening to me almost every day now. But I know mine is caused by icy roads and my traction control kicking in.


#9

A way to check OP’s Camry would be to turn off traction control if they have such a switch. Not sure about that model/year.