My car engine just started knocking or pinging

My car has been having overheating issues…when it over heats the car dies temporarily

My car has 136000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
If you have been overheating your engine over and over, then it will cause damage to the heads and engine. Look at the oil to see if the oil has coolant in the oil. It sounds like you now have a lower engine knock and pinging is from the car running hot. Have a mechanic check diagnose the overheating issue in person to pinpoint the problem and make the appropriate repairs.

How to Identify and Fix Common car Problems ?

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

If your engine begins to run out of coolant, the engine will run hot and begin to knock and ping. Low coolant results from either an external leak from a hose, a damaged radiator, or an internal leak from a head gasket or intake gasket.
Engine knock or pinging occurs when a separate pocket of air-fuel mixture ignites after the spark has ignited the air-fuel mixture within the combustion chamber. The fuel-air charge is meant to be ignited by the spark plug only, and at a precise point in the piston`s stroke.
Knocking occurs when fuel burns unevenly in your engine`s cylinders. When cylinders have the correct balance of air and fuel, fuel will burn in small, regulated pockets instead of all at once. (Think sparklers, not fireworks.)
An engine knock can usually be attributed to a detonation problem, which is why the knocks shouldn`t be ignored. Bad engine detonation can cause catastrophic engine failure if the problem is left unchecked. Techway Automotive can inspect your engine and find the cause of your engine knock.
The short answer is: Yes, this is possible. Knock sensors, and many other engine sensor types, have coiled electrical wires, which can fracture with heat and vibration, causing them to malfunction.
Knock occurs when the peak of the combustion process no longer occurs at the optimum moment for the four-stroke cycle. The shock wave creates the characteristic metallic “pinging” sound, and cylinder pressure increases dramatically.
Raise the Fuel Octane

A fuel`s octane number is a precise expression of its propensity to self-ignite. The higher the number, the greater its ability to resist light-off. As the compression ratio or boost increases, so must the fuel octane. Eliminating engine knock can be as simple as using a higher-octane fuel.

Wait until the gauge moves back to the normal range or the light extinguishes before you open the hood. DON`T wait for it to get better on its own. An overheating engine won`t repair itself, and you should bring your car in to Jiffy Lube as soon as you can.
An overheating engine won`t resolve on its own, even if it seems to be fixed after you add a little coolant. It will only get worse if left unaddressed.
If the smooth rumble you`re used to coming from your engine is replaced with a repetitive tapping or pinging sound that becomes louder and faster as you accelerate, that`s a classic sign of engine knock.
Once an engine starts to knock, the rod can fracture without warning. It could be the next time you start it in your driveway, or it could keep going for six months. Eventually though, the engine will blow and you`ll be stranded somewhere.
What Is the Difference Between Detonation Knocking and Rod Knock? The difference between detonation and rod knocking is that the former is a problem with the detonation in the combustion chamber and the latter means the pistons are clanking against the cylinder walls.
If you notice that your engine overheats, the coolant temperature sensor could be the problem. At times, the coolant temperature switch may fail such that it starts transmitting hot signals permanently. This causes the computer to erroneously counterbalance the signal, thereby causing the engine to misfire or overheat.
Signs Your Ignition Timing Is Off

Some things to look out for: Engine knocking: Engine knocking occurs when the air-fuel mixture is ignited too soon in the cylinder. The mixture then pushes against pistons that are still trying to compress the mixture. This causes loud pinging sounds to come from the engine.

That said, a severely overheating engine can cause the cylinder walls or the pistons themselves to warp, bend and deform. This will cause the perfect seal between the piston and the rest of the engine to lose integrity. Oil could be forced past the piston rings and into the engine, where it will burn the oil.
Once an engine starts to knock, the rod can fracture without warning. It could be the next time you start it in your driveway, or it could keep going for six months. Eventually though, the engine will blow and you`ll be stranded somewhere.
Engine overheating is the most common cause of a cracked block. When the engine gets too hot, the block can crack as a result of thermal stress. Also, the block can crack in freezing temperatures if the cooling system is filled with too much water and not enough antifreeze.
Once an engine starts to knock, the rod can fracture without warning. It could be the next time you start it in your driveway, or it could keep going for six months. Eventually though, the engine will blow and you`ll be stranded somewhere.
Low coolant can sometimes cause a head gasket on your engine block to blow. If this happens, you may notice smoke emitting from the engine or tailpipe, a loss of power, engine knocking sounds, or decreased efficiency.
Low coolant can sometimes cause a head gasket on your engine block to blow. If this happens, you may notice smoke emitting from the engine or tailpipe, a loss of power, engine knocking sounds, or decreased efficiency.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

My car will not start Intermittently. I purchased a new battery 2 weeks ago and yesterday the car wouldn’t start. Got a jump and
ANSWER : The issue you are having is probably due to an intermittent fault in the starter motor itself or a deficiency in the starter electrical circuit, for example a large voltage drop due to a poor ground or a high resistance connection. These issues can be readily diagnosed and resolved on a mobile basis if you request a hard starting diagnostic. If you request that diagnostic, the responding certified mechanic will get this resolved for you promptly. Based on Toyota’s Factory Service Manual, the battery should not be disconnected if the vehicle engine is running. The battery acts as a large resistive voltage sink and consequently taking the battery out of the circuit, while the alternator is still running, can create a voltage spike on the car’s electrical system which is not good for voltage sensitive components such as the engine computer. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

Car engine dies
ANSWER : The first thing I would do is have the turbo/intake system ’smoke’ tested or visually inspected for any leaks. Without a smoke machine, you could spray your engine and turbo system with brake cleaner and listen for idle changes to help determine if there is a leak. The brake cleaner method is not as effective as using a smoke machine.

Next, checking your fuel pressure is in order to see if you lose fuel pressure as it sits or if the fuel pump in the tank is weak. If the fuel pump in the tank is weak or losing pressure, it would cause the engine to crank as you mentioned. Performing a fuel pressure test is not easy and requires a special tool. If you want to have this looked at a technician from YourMechanic can come to your car’s location to diagnose your stalling issue.

Map sensor car won’t start up good ?
ANSWER : Your MAP sensor is an important input for your computer. It helps determine the load on the engine to calculate the correct amount of fuel to inject. It sometimes takes a few seconds for the vehicle to realize that the sensor is not producing a good signal.

At that point, it will use other methods to determine the fuel rate, such as pre-programmed fuel maps, throttle position, etc. I would suggest replacing the MAP sensor and retesting. If you would like to have it checked first, a certified technician from YourMechanic will be able to scan your vehicle and test components to determine the root cause of your starting issue before making a repair.

car hesitates when trying to start the car ,but when started then i shut car off and start again it will start right up
ANSWER : Hi there:

Sometimes when you have problems starting an engine initially it is caused by a restriction in fuel flow; caused either by clogged fuel injectors or the throttle body that needs to be cleaned. Once the fuel starts to flow and engine warms up, it’s much easier to start. However, it could also be an air filter, EGR valve or other components that causes this issue as well, which is why it’s best to have a professional mobile mechanic complete a car is hard to start inspection so they can pinpoint the source of this issue.

Car won’t start. The check engine light, battery light, and oil change light are coming on. I tried jumping the car and nothing happened. Why won’t my car start?
ANSWER : Hi and thanks for contacting Your Mechanic. If sometimes your vehicle will start with the new alternator and sometimes it won’t, then there is a loose connection in your charging system. Check all of the wires to the alternator and to the battery. Make sure that the battery cables are clean and tight. Make sure that the wires to the starter are clean and tight. A loose ground to the ignition system will cause the vehicle to not crank over. Check all of the ground wires from the battery to the starter. Make sure that they are clean and tight. If you need further assistance troubleshooting your no start situation, then seek out a technician, such as one from Your Mechanic, that can assist you.

Out of the blue when I started car, the engine and gas was fine when cranked but the car did not fully start. The engine oil pressure light came on.
ANSWER : Hi there. Check the engine oil level. If the oil level is low, then top off and recheck the symptoms. If the engine oil is full and the oil pressure light is lit up on the dash, then either the oil pressure sensor has failed or the oil pump has failed. Take a look at the oil pressure sensor and see if the contacts are loose or damaged. If the oil pressure sensor seems to be intact, then I recommend removing the sensor and putting in a test gauge and checking the oil pressure as the engine is cranked. If there is oil pressure of 25 psi or greater, then the oil pressure sensor needs replaced. If there is no oil pressure, then the oil pump needs replaced. If you need further assistance with your warning lights being on for the engine oil, then seek out a professional, such as one from Your Mechanic, to help you.

The car crank but won’t start
ANSWER : Hi there. This does sound like an issue with the wiring. If the check engine light is coming on every now and then this means that when it does not come on there is no power to the computer. This can be the wiring harness issue or an ignition switch problem. I would have to test for voltage to the computer when the problem is occurring to be able to find where the issue lies. If you need assistance, a certified YourMechanic technician can be dispatched to your location to inspect your vehicle’s non-start issue and suggest any necessary repairs.

Car won’t start after seeing engine hot turn a/c off warning light.
ANSWER : Hi there. Check the battery cables and make sure that they are tight and clean. Then check the battery voltage and see if it has a voltage of 12.6 or 12.4. If the battery is less than that, then the battery needs charged. If the battery has 12.4 volts or higher, then place a load tester on the battery and see if the battery can hold a charge when a load is applied. If the battery drops under 9.6 volts, then the battery is no good and needs replaced. If the battery drops to 11.5 volts, then there is a dry cell and possible a burned cell and the battery needs replaced. If you need further assistance with testing your car battery, then seek out a professional, such as one from Your Mechanic, to help you.