misses at higher speeds

My Saturn seems to lunge or miss when I drive at higher speeds of 60 – 70 mph and loses power. It runs fine at lower speeds. Do you know what could be causing this?
Experienced mechanics share their insights in answering this question :
Slight surges at higher speeds under steady cruise like this, can be an indication of a transmission or clutch slippage issue. This is possible because of the drive gear ratio automatic transmission internal wear, or clutch disc wear on a manual transmission, will become pronounced at higher speeds. You may need to have a mechanic inspect the loss of power issue and recommend repair alternatives.

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

From the spark plugs to the ignition coils, many different things can cause an engine to misfire. The most common causes of misfires are worn, improperly installed, and mishandled spark plugs, malfunctioning ignition coils, carbon tracking, faulty spark plug wires and vacuum leaks.
If an oxygen sensor or mass airflow sensor is failing, it could give incorrect data to your engine`s computer, causing the misfire. When a vacuum line is broken, it can cause a fuel-injected motor to misfire.
An engine misfire is when one or more cylinders doesn`t produce power, and there are several possible causes, from a fouled spark plug to a clogged fuel injector or faulty oxygen sensor.
The most common causes of engine misfires are: worn spark plugs, weak fuel injector, vacuum leak, worn valve seals, carbon tracking, and no voltage at the coil. Misfiring engines should be looked at as soon as possible, as the problem can worsen over time and damage internal components of the vehicle.
Improperly functioning spark plugs cause an uneven burn of fuel in the engine, resulting in fluctuating RPMs and a louder noise.
There are a few common causes that cause engines to backfire: damaged valves, bad ignition timing, or an air/fuel mixture that`s not quite right. backfires happen when your vehicle`s air/fuel mixture combusts outside its designated spot in the engine`s cylinders.
Yes. While the damage may seem small initially, the longer you drive with a bad oxygen sensor, the worse the damage will become. Eventually, you may experience rough idling, poor acceleration, engine misfires, an illuminated check engine light, and failed emission tests.
The OBD II system detects misfires on most vehicles by monitoring variations in the speed of the crankshaft through the crankshaft position sensor. A single misfire will cause a subtle change in the speed of the crank.
You will feel a loss in power while accelerating and at times intermittent jerks. To solve this issue find the fuel filter located in the engine bay or near the fuel tank in your car`s trunk. If the fuel filter is clogged replace it if you have the skills to do so or get it changed at your local mechanic shop.
This hesitation while accelerating can be the result of a number of issues, including something like a clogged fuel filter or even a broken fuel pump. Sometimes, something could also be wrong with the transmission.
Vacuum leaks, especially those that are confined to one cylinder, will cause the engine to idle unevenly and possibly misfire. This is because the vacuum leak allows additional air to reach the affected cylinder, diluting its air/fuel mixture.
Fuel-related misfires can be caused by too much fuel. Fuel-related misfires can be caused by too little fuel. Fuel-related misfires can be caused by incorrect atomization of the fuel by the injector. Fuel-related misfires can be caused by bad fuel.
Intermittent misfires are almost always caused by a weak spark or a lean fuel mixture. That piece of knowledge may not tell you what exactly is causing the misfire, but it should lead you toward a coil problem or an injector problem. Random misfires are another type of misfire that can be very difficult to diagnose.
Symptoms of misfiring spark plugs include rough idling, uneven power when accelerating, and an increase in exhaust emissions.
A defective positive crankcase ventilation (PCV) valve or a malfunctioning exhaust gas recirculation (EGR) valve also can cause a backfire.
One of the most common causes of a sputtering engine is an issue with the vehicle`s fuel system—the filter, pump, and injectors. These three critical components work together to ensure fuel flows smoothly from the fuel tank to your engine`s fuel injectors, and then pumps into the engine evenly.
Misfires don`t simply go away – they need to be addressed immediately. Even if they don`t get worse, they certainly won`t get any better unless you take the car to a mechanic.
Use a spark plug socket to remove the plug to get a good look at it. The damage you see will help you determine the cause of the misfire. If the spark plug is just old, replacing it may solve the problem. Make sure to replace and properly gap new spark plugs.
Yes. While the damage may seem small initially, the longer you drive with a bad oxygen sensor, the worse the damage will become. Eventually, you may experience rough idling, poor acceleration, engine misfires, an illuminated check engine light, and failed emission tests.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Problem with speed. No check engine light on but when accelerating speed, it decreases then speeds right back up. No stalling at all
ANSWER : Hi, thanks for writing in. This is a common problem associated with fuel/air delivery which is very commonly related to what is called a mass airflow sensor. This monitors the flow of air intake into the throttle body as it is mixed with fuel to deliver the right air/fuel mixture into the motor. When this is not working properly, this will cause this kind of hesitation or surging when trying to accelerate. I would recommend having an expert from YourMechanic come to your home or office to confirm a diagnosis on the issue and make or suggest the necessary repairs or replacements.

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when driving speed slow down and resume to speed it begins to jerk i have to put in over drive to resume speed especially on hiway
ANSWER : You should have the vehicle scanned. The data from the speed sensor needs to be checked to see if the transmission or engine is the cause of the jerking. You may have a transmission solenoid that’s not shifting correctly, an engine misfire, or a sensor malfunction. Have a certified mechanic, like one from YourMechanic, scan and test your vehicle for you to properly diagnose the car’s jerking symptom.

Read Full Q/A … : misses at higher speeds

misses at higher speeds
ANSWER : Slight surges at higher speeds under steady cruise like this, can be an indication of a transmission or clutch slippage issue. This is possible because of the drive gear ratio automatic transmission internal wear, or clutch disc wear on a manual transmission, will become pronounced at higher speeds. You may need to have a mechanic inspect the loss of power issue and recommend repair alternatives.

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car is barely picking up speed from stationary position to 3rd gear
ANSWER : Hi there. Check the turbo on the engine. With the loss of power until the vehicle is driven normally after 100 meters and the lack of power going up steep hills, the turbo could have failed causing the engine to lose power. Remove the intake hose to the turbo and start the engine. Look to see if the turbo is spooling up or not. If its not spooling up, then the turbo shaft could be seized and would need replaced other wise the waste gate could be not functioning causing the turbo to stop boosting. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your loss of power.

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my land cruser vx 100 series the rpm would not drop down at the speed of 100 kph revs goes higher to 3200 rpm
ANSWER : The transmission is not shifting into the overdrive gear for you. This may be due to the shift linkage not positioning the linkage correctly due to a worn shift linkage.

The other possibility is a fault with a shift solenoid. The transmission would need to be pressure tested for transmission solenoid operation.

If you need some assistance with this, consider YourMechanic, as a certified technician can diagnose your high idle and make the appropriate repairs to your vehicle.

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Low thunk when, at slow speed, the gas pedal is pressed. What could cause this? 2005 Jeep Grand Cherokee
ANSWER : Hi there – most likely, the "thunk" you describe is coming from a weak or failed motor mount. It is allowing the engine to move about when you apply the accelerator pedal, and the engine is hitting something in the engine compartment. I recommend an engine mount inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, confirm this diagnosis, and give you an accurate assessment of damage and cost estimate for repairs.

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Heavy shaking that stops at high speeds
ANSWER : Considering the mileage on your car, there could be some worn out pieces in the front and rear suspension. The links that attach the wheels to the body of the car have rubber pivot points that eventually lose their elasticity and begin to crack and tear. This might be what is causing your creaking sound. The vibration you’re getting may be related to that, or it could be that you have badly balanced or worn tires. Vibrations caused by an imbalance often go away above certain speeds. For your safety and peace of mind, you should have this checked out. You can have that done at your convenience by contacting Your Mechanic. They can send a technician to your home or office to check out your Hyundai and let you know what steps need to be taken.

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Grinding/Scraping noise from the front right of the car when driving at low speeds.
ANSWER : If there were something in the way of foreign material (e.g., road debris) stuck, you’d probably hear the noise all the time. The noise may be due to the brake pads (particularly if they are not OEM pads). Non-OEM pads sometimes have chunks of metal in them and if the caliper is sticky, at take-off (i.e., while still at low speed) the pad may be rubbing against the rotor until you get to a high enough speed that the pad finally retracts. It is also possible that the brake dust cover is contacting the rotor, because it was impacted and bent, but the noise should be present all the time if that is the case. Really, the first thing to examine is the brake assembly (pads, caliper, pins in torque plate, rotor, dust cover) on the right side. If the source of the noise is not found there, obviously another rotating component is responsible and that means stuff like axles and the transmission. Be sure it is really wheel related, though. It is possible for accessory drives and pulleys to make noises, too, and such could disappear at higher RPM, just as you are describing. In any event, inasmuch as the noise is so obvious, the origin would be quickly identified during an actual, on site noise diagnostic. Such can be scheduled by YourMechanic at your convenience and performed right at your location. Please let us know if you have additional questions or concerns.

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