trouble cranking engine over

[joey7478]

New starter and tried 3 different batteries that all said charged. Engine will turn about three turns and then it acts dead. Battery shows 12 volts after trying to start. what might be the problem ? Thanks joey!

 

[RayInStl]

New starter and tried 3 different batteries that all said charged. Engine will turn about three turns and then it acts dead. Battery shows 12 volts after trying to start. what might be the problem ? Thanks joey!

First, do not use they trucks starter until you have found the problem. You risk damaging the starter, the electronics, or the battery. Maybe even the motor if gas is filling a cylinder. Do the following in order:

Try turning the engine by hand with a socket wrench. Should have resistance but it should turn freely. If it does not, take any belts off and try again. If it's easier to turn, start turning the pulleys of the accessories (alternator, a/c compressor if equipped, etc.) One of them may have seized or is about to.

If it's NOT easier, you have an internal mechanical problem with the motor. Check your oil dipstick to make sure then engine hasn't seized from lack of oil. If the oil is ok, remove all of the spark plugs and turn the motor with your socket wrench. See if liquid comes out of any of the spark plug holes.

If liquid does come out, smell if it's gas or coolant. You could have a blown head gasket letting coolant into the cylinders. You might have a failed pressure regulator or injector that's filling a cylinder with gas. Liquids don't compress. Do not attempt to start the truck until you have found the source of the liquid. Running an engine with coolant in it will wipe the bearings. Running an engine with liquid in the cylinders can damage the engine because liquid does not compress. You can very easily bend a valve or do other damage to the motor.

If no liquids come out of the spark plug holes, then I'm afraid the motor will need to be disassembled to find what is broken.

Good luck!

Ray

 

[joey7478]

First, do not use they trucks starter until you have found the problem. You risk damaging the starter, the electronics, or the battery. Maybe even the motor if gas is filling a cylinder. Do the following in order:

Try turning the engine by hand with a socket wrench. Should have resistance but it should turn freely. If it does not, take any belts off and try again. If it's easier to turn, start turning the pulleys of the accessories (alternator, a/c compressor if equipped, etc.) One of them may have seized or is about to.

If it's NOT easier, you have an internal mechanical problem with the motor. Check your oil dipstick to make sure then engine hasn't seized from lack of oil. If the oil is ok, remove all of the spark plugs and turn the motor with your socket wrench. See if liquid comes out of any of the spark plug holes.

If liquid does come out, smell if it's gas or coolant. You could have a blown head gasket letting coolant into the cylinders. You might have a failed pressure regulator or injector that's filling a cylinder with gas. Liquids don't compress. Do not attempt to start the truck until you have found the source of the liquid. Running an engine with coolant in it will wipe the bearings. Running an engine with liquid in the cylinders can damage the engine because liquid does not compress. You can very easily bend a valve or do other damage to the motor.

If no liquids come out of the spark plug holes, then I'm afraid the motor will need to be disassembled to find what is broken.

Good luck!

Ray

thanks that a lot to think about.

 

[pjtoledo]

turn the headlights on while cranking, do they get real dim? or do not dim at all? what does the voltage do while cranking? an old style needle meter is better than a digital for this test.
check on the actual battery posts, then on the cables. should be the same.
also check voltage between the negative battery post and truck chassis ground while cranking. any volts there means a bad ground cable/connection.

 

[joey7478]

turn the headlights on while cranking, do they get real dim? or do not dim at all? what does the voltage do while cranking? an old style needle meter is better than a digital for this test.
check on the actual battery posts, then on the cables. should be the same.
also check voltage between the negative battery post and truck chassis ground while cranking. any volts there means a bad ground cable/connection.

Thanks joey!