What causes a vehicle to hesitate on acceleration after stopping at a stop sign?
hesitation can occur when your engine is starved for something it needs. When stopped fully, accelerating to pull away uses more power than cruising or just driving at constant speeds. Your car will need more power which it gets from air, fuel, and properly timed and delivered spark, the combustion trio. It could be getting just enough to run OK at cruising but not enough when under hard acceleration.At higher than normal demands, any of these can be reduced by the following:dirty or corroded or worn out spark plugs, bad spark plug cables or improper engine computer timingplugged fuel filters or dirty or plugged fuel injectorsdirty air filter, dirty throttle body (see throttle tip hesitation)Bad sensors for air flow, fuel flow or exhaust or engine timing or position.
What are some things to replace when a car hesitates at low rpms?
First off figure out and diagnose why its doing that, or else you wont have a clue what it is or else youre going to just be throwing parts at it and money down the drain by just simply guessing. From my experience its not one cut and dry answer It could be lots of things. Most likely if it has a carburetor the carburetor needs an adjustment, or spark plugs are old and worn out, air filter is possibly worn out and clogged with debris so its restricting the airflow. Oxygen sensor is a possibility. Or it could be a fuel filter/injector clogged/ fuel pump blocking proper fuel flow. The catalytic converter or exhaust could be clogged up with carbon deposits, but i doubt that. Lastly if its really high mileage like 200,000–400,000 miles and it could just simply be old and worn out and the piston rings arent sealing very well, so its low on compression which will make most engines low on power but thats pretty unlikely especially if youve taken good care of it, done oil changes on time and its maintained. All these items are consumables, they are regular car maintenance repairs. Its amazing how much better a car will run when you replace all those things and wear out over time. Take it to a reputable ase certified mechanic or if the car is under warranty go to the dealer. Or if you got a buddy thats good with cars take it to him. The good news is its usually something simple, and all those things arent hard to fix unless its the fuel filter/fuel pump. tell me how it goes. Good luck dude!
Can a clogged catalytic converter unclog itself?
Well, it can happen that they will de-clog on their own, but usually need a helping hand. If it is utterly blocked, then dismantling and manually cleaning is the only solution.If the ceramic material inside is melted, then change it.Most modern Cats are stuffed with a ceramic honeycomb structure, unlike the older ones that had complex filters with platinum wool amongst other stuff inside them.One of the reasons they get clogged is people lugging around in fifth gear making lots of soot which clogs the honeycomb.A faulty EGR valve (gas recirculation) will do the trick as well.Faulty injection, allowing to much fuel to come through the exhaust can cause the honeycomb to melt when it starts burning the fuel... (replacement)But you can clear a blocked (not 100% blocked) converter by getting it hot enough to make it finish what it is supposed to do.The garages here in France have a naughty technique, they hoist the car up on lift with the motor going flat out, and stand underneath it holding a fire extuinguisher, just in case it sets fire to the car, or any flames from the now burning soot comes blasting out of the rear.It is a dangerous technique in my opinion, and not good for the engine, but it works. I don't suppose it works everytime either.So if you have a CAT that is partially blocked because you mooch around in fifth gear or have bad driving habits, you could try driving the vehicle hard enough to heat the CAT as it should be, where usually it can clear itself.So , if it is soot build up, there is hope for you, to unclog it without taking it off the vehicle and or changing it, if it is hard blocked with mineral deposits, unlikely. If it is melted, its got to be changed.
Why do you have to change a car's alternator when changing the battery?
Well, three possibilities here.One. You alternator failed, killing the battery. Replace the battery, test the alternator. You can't test an alternator with a failed battery. Start the car with the new battery, voltage should go up from 12.5ish to 13–14 volt range.Rev the engine slightly (2500–3000 rpm). Turn on all the electricals, lights, air conditioning, etc. If the voltage drops below 12.8 for more than a second, look at replacing the alternator. It should spring back to 13ish.Often alternators will have a modular regulator. Most parts shops can test and determine if the alternator itself is blown, or if it's just the regulator. The brushes may be gone, and are sometimes integral to the regulator. Either way, it's cheaper than a full alternator.If the alternator is bad — doesn't make voltage; or is weak — doesn't hold voltage: then fix or replace it with the battery.Check the feed cables and battery connections on the off chance they're bad. You should do this regardless.Two. This is a low probability. Your battery failed, killing the alternator. This can happen in the case I forget a dead short in one of the cells of the battery, or a near total loss of liquid in your battery. Either way the battery case will likely be distorted, or even cracked. It will have a voltage less than 9. It may even stink of rotten eggs, with a slight taste of chewing on foil.Three. Your mechanic is a liar and a thief who's trying to get more money out of your pocket and into his. If he says that you have to replace the alternator because the battery is bad, this is the case.
What problems go along with a bad catalytic converter?
A clogged catalytic convertor causes the symptoms of a loss of power when accelerating or going up a hill. This is an often overlooked cause of loss of power, can cause check engine fault codes and lights, and mechanics will often change a few parts unnecessarily , especially if it is only partially plugged. A couple ways I check for plugged cats when a low power complaint is a symptom, and other obvious basic maintenance items have been checked for service is to have someone hold the rpm at about 1800 to 2000 steady. Then check for a good push of exhaust with my hand from behind the tailpipe. A plugged or partially plugged cat typically leaves a hot sickly feeling exhaust flow from the tailpipe. Compare to a known good working car nearby, known to be performing properly and with the same amount of cylinders. That slow , hot sickly flow at 2000 rpm compared to the hard push blowing your hand away of a not clogged cat is a dead giveaway, and I have NEVER misdiagnosed a plugged cat , or made false diagnosis with this method. Another way is watching a vacuum gauge connected to the intake manifold. When revving up, if the exhaust is plugged the gauge reading will climb then begin to slowly drop as the exhaust pressure builds up. Further testing will be needed to verify which part of the exhaust is plugged. Diagnostic by codes is unreliable and until now I had not heard of it. A code p420 only refers to catalyst efficiency. And can be set by faulty o2 sensors. Removing the exhaust and testing for engine power returning to normal works. But the hot sickly flow has been most accurate with my experience, in several cases where shops had missed it, were stumped and called me to come check. They are always embarrassed for missing the simplicity, but need not, as cars and their complicated electronics and even age old problems can lead to loss of power without any immediately obvious cause.
What will happen if I drive with a very low transmission fluid?
It depends on whether your car is an automatic or manual transmission.Automatic: Automatic transmission fluid has multiple jobs in an automatic transmission. First, it is used for cooling the transmission. So, with low transmission fluid, your transmission will not be cooled properly. Second, it used to make the torque converter operate, and provide pressure to ensure proper operation of the various clutches and components within the transmission. Third, it is used to lubricate your transmission. If your transmission fluid is very low, the transmission will almost certainly be slipping. So it will feel like the vehicle is in neutral, with the engine revving, but no power being applied to the wheels. The shifts will be rough, if they occur at all, as the clutches are not getting proper pressure to perform shifts smoothly. If the transmission fluid is very low for a long period of time, the clutches will burn up from not being able to lock up properly, and the torque converter will likely fail due to improper fluid pressure. If you drive your automatic transmission vehicle with low transmission fluid, at some point, you will be looking at a bare minimum $2,000+ repair bill unless you are able to do the work yourself, in which case it will still be $1,000 plus.Manual: In a manual transmission, low transmission fluid will cause the gears, synchronizers, shift forks, and other components to wear quickly. The bearings within the transmission will also not be lubricated properly, and the transmission will begin to overheat. It will likely be quite difficult to shift the transmission between gears, if not impossible. A manual transmission with low fluid may last longer than an automatic transmission with low fluid, but the prognosis is still the same. Transmission failure will occur, at some point, sooner or later.If your transmission fluid is low, it is much cheaper and safer to fill it, rather than face the expensive repair bill. Fill the transmission fluid and keep an eye on your vehicle, as it is likely that you have a leak, especially if your transmission fluid is frequently low.
Why is my car shaking and the check engine light flashing?
A shaking vehicle AND flashing MIL ("check engine light") sound like the vehicle is misfiring on at least one cylinder. As @Anna Nguyen, @Brendan Sinclair, @Antoun Nabhan and others have said, it could be an ignition related problem. It could also be fuel-related. If one or more fuel injectors are clogged or dead, that would also cause a misfire in the affected cylinder(s). These are relatively cheap/easy things to check and fix.Other causes (which could be more complicated and more expensive) to fix include contaminated fuel, a bent intake or exhaust valve, a broken valve spring, a damaged piston/connecting rod, and on and on.I recommend getting a scan tool and checking the codes which are causing the MIL to light/flash and I also strongly recommend NOT driving the vehicle until the problem is fixed. If you continue to drive the vehicle as is, you will exacerbate the problem. Dumping unburned fuel into the exhaust due to a misfire will overheat and kill your catalytic converter. A more serious problem like a bent valve can eventually cause you to crater your engine (i.e.: completely destroy the engine).
What are the effects of driving a car with a misfiring cylinder?
OK. I am a gear head who loves working on cars and has done so since the 1960’s.If a cylinder is misfiring because of an ignition problem you will, in the short term, just experience a loss of power increase your fuel consumption. In the longer term, continuing to drive it that way could destroy a coil and cost you more money.If, however, the misfire is caused by an injector problem, you could seriously damage your engine. Running that cylinder too lean will cause it to overheat and potentially damage the valve or the piston. If it is running excessively rich the unburned fuel could be washing the lubrication off of the cylinder walls leading to severe wear. In either case, repairing the damage will be expensive.NEVER drive a car that has a problem. NEVER drive a car in which the Check Engine light is on. If the Check Engine light begins to flash, SHUT OFF THE ENGINE, NOW! A problem that to you seems small, if not repaired, can cause a lot of damage that will be very expensive to fix.Read your car’s manual. Do exactly what it recommends. Find a mechanic you trust. Doing preventive maintenance will cost you a lot less than repairing the damage caused by neglecting to keep your car serviced.
What are some symptoms of a bad idle air control sensor?
Idle air control valves open to allow more air to "leak" into the intake, raising the engine rpms, or close when not needed. When your AC compressor kicks in or power steering is activated as you suddenly turn the steering wheel, the sudden drag on the drive belt will bog down the engine. These systems send a signal to the engine computer telling it they are active and it then signals the IAC valve to open, which increases the engine speed. Without this occurring, the engine could struggle, or die. The IAC valve can cause weird idle issues, mess with throttle functionality or cause the car to die. Sometimes they fail, get stuck or just get all carboned up. Sometimes people have success at cleaning them, but generally it is best to replace them when bad. Idle issues and even problems with the IAC valve may not be due to the IAC valve being bad itself. An idle issue does not mean the IAC valve is bad. It is best to pay close attention to how the vehicle is acting, and then communicate that clearly and as completely as possible to your mechanic. Intermittent problems can be very hard to diagnose. Details will help. Knowing more about the vehicle in question and its symptoms (in detail) will also help in understanding more about what it is doing.