Why car cranks but wont start after over heating

Well as i was driving i dindnt notice the bottom coolant hose had fell off till i stoped and seen smoke under my hood and car shuts off ..i filled car back up with proper fluids and noticed milky substance I'm oil ..i changed head gasket myself and still car wont start ..im starting to think catalyst converter ??

My car has 210000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hello,
It sounds like you may still have a leak between the cylinder head gasket and the cylinder head allowing coolant to leak into the oil passages and cylinders. A blown head gasket may cause a number of different symptoms. A head gasket that fails between cylinders will generally cause a misfire and potentially compression leaks from one cylinder into another. Low compression will eventually result in a rough idling engine and eventually cause the motor not to start as you have described. I would recommend having an expert from YourMechanic come to your location to properly diagnose the symptoms you describe.

How to Identify and Fix Common car Problems ?

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

A damaged fuel system is the most common reason an overheated engine may not start. A faulty system can cause the motor to get hot and produce heat and vapor, which creates difficulty for the fuel to circulate in the engine. Blown head gasket. A blown head gasket could also be a significant cause of overheating.
Find an ideal spot, turn off the engine, and stop the car. Check the coolant level and if there is no leak, add coolant. If there is a leak, get help from a professional, as it is a serious issue. Start the car once the issue is solved, or get the vehicle towed if the issue persists.
The most common reasons a Hyundai Accent won`t start are a dead battery, an alternator problem, or failed starter.
If the car cranks when you turn the key, but the engine won`t start, it could be because fuel isn`t getting to the engine. One potential reason for this could be dirty fuel injectors. Over time, the fuel injector nozzles can become clogged with rust, corrosion or debris.
How long can a car overheat before damage occurs? It only takes 30-60 seconds of overheating for permanent damage to infiltrate a vehicle. As soon as you notice signs of overheating, you need to act. Failure to do so might result in troubles like coolant leaks, damaged radiator caps, and a faulty cooling fan.
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.
Car Won`t Start:

If your car doesn`t start, it could be because your radiator is overheating. Your car`s engine can seize if it gets too hot. If you think this might be the problem, have your vehicle towed to a mechanic so they can take a look. Don`t ignore these bad radiator symptoms!

Dead or corroded car battery. Clogged fuel system. Loose starter. Damaged ignition.
The most common reasons a Hyundai Sonata won`t start are a dead battery, an alternator problem, or failed starter.
Loud popping, knocking, and stuttering noises from the hood of your vehicle are cause for concern, and could be a sign of major engine damage.
As temperature of an engine exceeds 230 degrees Fahrenheit, the engine is overheated. Above 245 degrees Fahrenheit, damage may occur.
As soon as you notice an issue with your vehicle, the next course of action is to pull off the road to a safe and clear area and turn off the vehicle. If the vehicle is overheating, continuing to drive with a potentially damaged engine may cause permanent damage.
Hyundai vehicles are commonly reported as having engine problems, varying from ticking or unusual noises, to stalling, cutting out or seizing.
Some other typical reasons engines fail to start include:

Low or discharged battery. Corroded or loose battery cables. Starter motor relay failure. Ignition switch failure.

Many modern Hyundais and Kias lack a useful anti-theft device called an immobilizer, which prevents a vehicle from starting when someone attempts to use a key or key fob that doesn`t match the car.
There are a few things that can cause the crankshaft position sensor to fail, including damage, debris and faulty circuitry. Even for modern electronics, the engine is a violent and destructive environment. Though built for this, most sensors eventually succumb to the ever-present heat and vibrations of the engine.
The crankshaft sensor is one of the key providers of information of the engine control. It detects the speed and position of the crankshaft and forwards this information to the engine control in the form of an electrical signal.
Connected to the battery is the alternator, which works to generate power for your vehicle`s electrical components. When you have a brand-new battery but still can`t start the car, the alternator might be the issue. Cold and damp climates may increase wear on an alternator, causing it to fail.
A blown fuse signals a short circuit. This occurs when an electrical component draws a stronger current than it is designed to handle due to the device malfunctioning.
With the fuel pressure gauge attached, start the engine and let it idle. Disconnect the vacuum hose from the pressure regulator; the pressure should drop approximately 8 to 10 PSI. If it does not, suspect a problem with the regulator or its` vacuum supply.
Start your car`s engine and allow it to idle. Look through the radiator filler neck to see if the coolant flows. At this time, it should not be flowing as your car has not reached the operating temperature to cause the thermostat to open. If you find the coolant is flowing, it means the thermostat valve is open.
Low engine oil is an indicator that there is a problem with the engine. If the level gets low, it can prevent proper lubrication of critical components inside the engine and cause starting problems, engine failure, and damage to critical components.
Driving your car when it`s overheating can cause serious – and sometimes permanent – damage to your engine, so it`s best to stop driving as soon as possible. Pull over and away from oncoming traffic, then turn off the engine. Open your hood (or call for help).

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 won’t crank when it’s cold and now won’t start at all
ANSWER : Hi there:

Usually this issue is cased by low cranking amps inside the battery. If you’ve recently had the battery replaced, it’s possible that an electrical component that makes up the charging system might be damaged or faulty. It’s also quite possible that the main electrical relay or the starter relay is giving you fits. To know for certain what the exact issue might be on your 1989 Toyota Camry, you should have a professional mobile mechanic complete a car is hard to start inspection, so they can pinpoint the source of your issues and recommend the right repairs.

When I go to crank my car the key stays in the start position and the car is constantly trying to crank itself.
ANSWER : First, let’s make sure about some terminology before I proceed. I will assume the motor is actually turning over. If the car is trying to start, the motor has to be turning over or it is not trying to start. This is an important distinction when diagnosing the starting system. As a technician, I go to different parts of the system based on this description.

If the key is stuck in the start position, this is a ignition lock cylinder issue and the reason the starter continues to turn the motor over. If the starter is turning but the motor is not, then the starter is likely the problem. Either that or the teeth on the flex plate are all gone. This would require removing the transmission to repair.

If the car runs intermittently, this can be a big challenge. And it also means the starting system is working. It will need to be diagnosed when it is failing. A working car cannot be diagnosed because there is nothing wrong. Where you park your car should not have any affect. It certainly could be a wiring problem. Wiring problems hide really well and can happen anywhere in the miles of wires that are in your car. Isolating the system that is failing is really important here. At the moment I am unsure which system is failing. Starter system, ignition lock cylinder and or ignition switch electrical or something with the engine control system.

When the car is failing, you need to check for spark and fuel pressure. If neither is present, this is a clue. Usually the crank sensor will do this. Does your car have a tachometer? If so, does it move at all when cranking. This is a clue whether or not the cam and or crank sensor is working. Is there a Check Engine Light on with the key on? If there is a Check Engine Light, the code or codes can be used for specific diagnosis.

All of these concerns will send you down a diagnostic path. Be sure not to confuse yourself by misinterpreting multiple system failures. If the key does stick in the start position, this would be the first problem to solve. After that, does the motor actually turn when the starter turns? After that, the question of "Why won’t it start?" is first answered by finding what the motor is lacking. Fuel, spark etc… Good luck.

If you need assistance with these checks, contact a certified mechanic who has the tools and experience needed to properly diagnose this starting issue with your car.

Why does my car start one day and the next day it wont start? The car will crank but wont turn over
ANSWER : Hello, thank you for writing in. With intermittent symptoms, diagnosis can take longer but is typically the same as diagnosing any other starting problem. The main issue is that you can only perform the testing needed when the issue is occurring. If the vehicle starts and works normally, all of the components are likely going to pass their tests. There are several components that will work intermittently. They include the fuel pump, charging system, a number of sensors, and any electrical connection that is loose. When the vehicle is not starting, test for fuel pressure, spark, and the electrical connection on any of the sensors that effects starting (air intake, camshaft/crankshaft position sensors). For more diagnostic help, contact our service department to schedule an appointment.

The car is having trouble starting up ,70 percent of the time it starts right up. the other 30 percent, it randomly won’t start its
ANSWER : Hey there thanks for writing in about your 1998 Honda Accord. This could be a few things. A faulty ignition switch, a failing crank sensor, or possibly other faulty sensors could be the cause. To have this taken care of, consider having a certified technician, such as one from YourMechanic, come to your car’s location to diagnose and repair the hard start issue.

Ok my car will not start it had the same issue a week ago I changed the cam and crank sensors. It cranks but wont start …HELP!
ANSWER : Prior to performing diagnostics be sure you have a fully charged battery that passes a load test. Then, confirm that the engine immobilizer system (security system) is not activated thus preventing the car from starting. To temporarily override the immobilizer system, see these instructions.

Be sure there is adequate fuel in the fuel tank and that the fuel is not old. Check for adequate fuel pressure, injector operation, and a spark at the spark plugs. Basically, if the starter motor is turning the engine over rapidly, at sufficient RPM, but the engine does not catch and run, that means that there is an ignition, fuel, air induction, or mechanical fault in the engine that will have to be repaired. Strictly speaking, you should first check engine compression in the cylinders because if there is no, or inadequate, compression the engine won’t run under any circumstances. If compression is found to be within factory specifications, and there is fresh fuel being delivered by the injectors (not just "to" the injectors) and the ignition system is working, that means that the air fuel ratio of the mixture delivered to the cylinders is so far off that the mixture just won’t ignite. Such could be due to a big vacuum leak, an air induction fault like a stuck idle air control valve or, considering fuel, could be due to a failed temperature sensor that must be working properly to signal the PCM to enrich the mixture on cold start. Other common faults are defective spark plugs or a defective coil. Regardless of the underlying cause, if you request a no start diagnostic the responding certified mechanic will get the problem diagnosed and repaired for you promptly. Please let us know if you have further concerns or questions as we are always here to help you.

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.

Fuel pump engages. Batery good, alternator good volts, jump start helps when wont start. Temp does not matter. Intermittent?
ANSWER : Hello. Thank you for writing in. There are several reasons your vehicle may only start when jump starting. The first and most common is a build up of resistance that is causing you to need a boost of voltage to get the engine started. This may be due to poor battery cables, a bad ground connection, a poor starter solenoid, and a couple of other issues. The first thing you want to do is perform a visual inspection of the starting system. Make sure there is no corrosion build up in the battery cables. You can also check the resistance across these wires and make sure you have a solid connection between components. You then want to make sure the starter solenoid is doing its job. It is responsible for taking the small amount of electricity sent by the ignition and turning it into a huge electrical charge that is strong enough to push over the engine with the help of some gear ratios in its favor. Do some more testing, and stick to the basics before assuming its something seriously complicated.