Q: Brakes bad and car running rough

asked by on February 16, 2016

My brakes seem to be failing. I have to apply a lot of pressure to stop my car. The brake pedal is hard to press as well. In addition, my Check Engine light is on, my engine seems to have lost some of it power, and my car rumbles and shakes while idling. Sometimes the car stalls and when at a red light, the car moves forward in a jerking motion when I press the gas.

Check Engine Light is on Inspection $94.99 - $114.99 Get a Quote

Hi, the first thing to do is to figure out why the Check Engine light is on. A certified technician will be able to hook up a computer to the car which will read the DTC (Diagnostic Trouble Code) which is what causes the light to illuminate. Once we have that code, it will help with the diagnosis of the vehicle. This sounds like you have a vacuum leak somewhere in the engine though, not the brakes failing. Modern cars have Power Brakes, in which we use the vacuum of the engine to assist the driver in applying the brakes. Without the correct amount of vacuum the Power Assist won’t be able to help out as much in applying the brakes. The other issues you mentioned will also happen when the engine’s vacuum is not at the correct level. Have a certified technician inspect why your Check Engine Light is on and also pull the DTC code to help further diagnose the issue.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Automatic transmission isn't shifting.
It is possible that the air actuated clutch is at fault but in the service manual there is a note the even though there is no adjustment to the shift linkage, excessive play due to worn parts or a loosely...
Transmission slipping when going uphill
Hi there. Your hybrid has a continuously variable transmission (CVT), which uses internal pulleys and a steel belt. The transmission control module (TCM) controls the shift pulley ratio via solenoids, while receiving inputs from various sensors throughout the vehicle. If...
Radiator is leaking
Hello. When a radiator is leaking, it is an issue which requires immediate attention. If you continue to drive under this condition, you will be running the risk of damaging other cooling system parts and ultimately, this could become very...
The car suddenly couldn't be started
Hello. If the engine will not crank at all and the starter and battery are fine then I start by checking to see if the starter relay is getting power (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-starter-relay). If it is but is not sending power to...
Leak into wheel well
You should have the A/C drains checked to see if the drains are blocked causing the water to leak into your 2008 Mercedes Benz R350. Dirt and debris that gets in the A/C evaporator case can clog the A/C drain...
P0446 trouble code
Hi there, thanks for writing in. This P0446 trouble code (https://www.yourmechanic.com/article/p0446-obd-ii-trouble-code-evaporative-emission-control-system-vent-control-circuit-malfunction-by-spencer-clayton) relates to the evaporation control system circuit, which is a restricted vent path for the EVAP (Emergency Vehicle Accident Prevention) system. There is a solenoid in this circuit (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-evaporation-vent-solenoid)...
Heat control blows hot then cold air
This may be due to a bad heater core. As you may know, the heater core is a small radiator like unit that circulates the hot coolant from the engine through the heater core which then uses this warm coolant...
I know about turning off new text message notifications on Uconnect, but is there anyway to turn it off completely? I still get th
Hi there. One of the issues with the Uconnect system on newer Dodge / Chrysler vehicles is the confusion on how to completely disable the system; so it won't interrupt music or other communication. The truth is there is no...
Why does my car vibrate when idle?
Hi There, It sounds like you may have a dirty or failing idle air control valve causing your engine idle to fluctuate and eventually stall. The idle air control valve (https://www.yourmechanic.com/services/idle-control-valve-replacement) is a small valve on the engine's intake system...

Related articles

How Often Should Brakes Be Replaced?
Brake pads and brake rotors wear out over time. How long brakes last depends on the brake material, as well as your driving patterns.
2012 Ford Focus vs. 2012 Mazda 3: Which One Should I Buy?
Compact sedans and hatchbacks provide a great ride on a budget, with the evolution from a stodgy, unattractive exterior (and interior!) to a more fully-featured trim set and exterior design. Driving enjoyment is improved throughout the class, which are known...
The Best Used Cars to Buy If You're a Skier
When When summer ends, skiers start thinking about hitting the hills, and that means having to contend with winter driving conditions. Not just any vehicle is going to get the job done. We have evaluated several used ski-worthy vehicles, and...