I drive a 2004 Saturn Ion. Sometimes, when stopped at a stoplight, the car will suddenly lurch forward about a foot, even though I have my foot firmly on the brake.
I heard that the car guys discussed this on the radio, but I missed that show. Has anyone else had the problem described?
I would check the master cylinder, as this is a symptom of a failing master cylinder.
If you wait, you could experience total loss of braking power while driving.
There is also the possibility that the engine is surging while at idle, thus indicating a possible problem with the Idle Air Controller (IAC). Does the tachometer register an increase in RPMs when this phenomenon occurs?
Would I sense fading of the brake pedal before the surge, if the master cylinder was failing?
Brakes can “fade” when they are overheated, as with too much brake use on a steep downgrade, but a brake pedal does not fade in the classic sense.
I assume that when you say brake pedal “fade” in this case, you are referring to the pedal sinking toward the floor. Is that correct?
A failing master cylinder will normally show itself by allowing the pedal to sink somewhat toward the floor when you are holding your foot on the pedal. As it gets worse, the pedal normally sinks closer to the floor. However, in rare cases, you can have failure take place more rapidly.
If there is any question regarding the functioning of your brakes, I strongly suggest that you get the car to a competent mechanic a.s.a.p. DO NOT take the car to Midas, Meineke, Monro, Sears, Pep Boys, AAMCO, or any other chain operation unless you want grossly overpriced, substandard work with lots of unnecessary “extras” on the bill.
To return to an earlier question, Does the tachometer register an increase in RPMs when this phenomenon occurs?
I’m not seeing any change in the tachometer when the lurch occurs. On the other hand, I’m not sensing that the pedal is sinking either.
Regardless, I’m going to follow your advice and get the master cylinder examined right away.