I have a 5.3 from an 05 Tahoe... When I got the motor it came with no starter so I got a used one off a 2000 Chevy 5.3

When you turn the key over you can hear the starter plunger kick out and a loud thunk like it hit a tooth on the flywheel.

If you keep turning the key over it keeps making that sound it will eventually catch and crank the motor. I've tried turning the motor over with a ratchet and some times have to turn it 4-5 times and it still won't start, or tap on the solonoid with a hammer and it will start.

I pulled the starter off and threw on a car starter and it does the same thing.

Went and bought a brand new starter for am05 Tahoe and it does the same thing.

The flex plate of not loose and all of the teeth are in good shape? Wtf hell is the problem because sometimes it will start right up like there's no problem

 

Anyone have an idea

 

Sounds like a weak battery. Starters pull a considerable amount of amperage, Check your battery, then go to the cables and connections, eliminate all that first. I doubt three starters are the issue.

T,

 

Brand new battery with brand new ternimans, the power wire to the starter is bigger gauge than my pinky and I'm getting 12.6 to the hot side of the starter when you turn the key over

 

That does sound like not enough juice.

Did you fully charge the battery before trying this? Wire brush the battery connectors? How is the negative post of the battery hooked up to the motor? I like running it straight to the block. If you ground the battery to the frame then you have a good ground strap to the block?

You might have a bad cable. Try hooking a set of jumper cables straight to the starter.

I assume each new starter had a new solenoid?

Finally did you check the clearance of the starter pinion with the fly wheel teeth?

 

Volts isn't really what cranks it though. You need amps, you must make sure the terminal ends are properly connected. If they are loose or dirty there may not be enough amps to turn the engine over.

 

Add 1 shim between the starter and the mounting plate. starter may be engaging to deep, had that happen on a few cars.

 

You also need just as much ground as positive. Check your engine grounding.

 

Correct bolts holding the starter on?

 

What transmission and flexplate do you have?

 

Using a stock 5.3 flex plate, 4l60 trans, brand new battery 1000 cranking amps, brand new terminals, brand new power cable from battery to starter.

The negative battery is grounded to the block, also have a ground from block to frame and trans to frame.

I installed a 1/64th shim between starter and block and still did the same thing.

Tested voltage in the signsl wire and it's getting 12 v when turning the key over.

You can watch the plunger shoot out when someone cranks the key over. The teeth on the plunger hit the teeth on the flex plate, they just don't mesh they look like their spaced right. What would cause the teeth not to mesh sometimes?


But it starts perfect sometimes and only every so often does it do this and not start.

I'm at a loss here

 

Also none of my connections are dirty or greasy, everything is new at this point

 

What size is the battery cable to starter? New means nothing if its to small and to far from the battery. Whats the voltage drop on the batt cable at starter during crank?

 

Battery is from my 95 f150 1000 cranking amps and 4 gauge cable to starter
And I'll check voltage drop tomorrow but I remember the voltage while cracking is 12v will double check what it drops tomorrow

 

Battery is a duralast gold part #65-DLG
cold cranking amps -850
Cranking amps at 32 degree- 1000

 

fly wheel installed backwards?

 

Flywheel has never been off of the engine, the car runs and drives perfect its the starting is the only issue I have with it

 

Shim it until the interference goes away.

 

Try running a jumper wire straight from the battery to the starter S terminal and see if that helps. Sometimes you can get excessive resistance in the key circuit causing the solenoid to not engage regularly. It may not do it every time. You can also jumper a screw driver across the battery lug to the big lug below it to jumper the whole solenoid.

 

I have jumped across the solonoid with a screw driver it cranks every time, I've checked voltage at the signal wire and it's always 12v when cranking