I ran into the store yesterday (5 minutes) and when I came out the engine turned over very slowly at first, then slower, then stopped turning over. It did not start. Then [CLICK-CLICK-CLICK]. I tried jumping it but that made no difference. I banged on the starter, no difference. I had it towed the half mile to my house and pulled the battery and starter, had them both tested and they tested fine. Battery is two years old (Interstate), starter is much older. I then tested the starter relay which is really old but appears to be working correctly. Then I checked the battery-to-chassis, battery-to-block and block-to-chassis grounds... all ohmed out at ZERO from battery ground to each anchor or anchor to anchor. I then tested voltage at the relay [12.56v], at the starter [12.56v] and then on the switched side of the solenoid when the starter is engaged [11.96v] but the starter is not turning. The lights are bright, there is no indication of a bad battery.

Is this a bad starter, despite it testing good? I watched it spin on the test bench. The gear extended and it everything seemed quite robust... on the bench.

Anything else you think I should check? I have a new starter but am reluctant to install because it's an expensive part to throw at it if that's not the problem. Your advice is appreciated.

 

I had a similar experience with an ex-girlfriend's old Subaru. I pulled the starter, it bench tested fine, all the electrical connections were good and ended up just replacing the starter and never had a problem after that.
To this day I still am baffled by the experience - perhaps the starter is too weak to turn the flywheel but looks fine when it's spinning freely. Beyond that there seems to be no reasonable explanation.

 

I've been here and it sucks! My angle was to meter the voltage right at the starter while she's not cranking. (Not so easy for me). If there is still maybe 9-1/2 or 10 or more volts it and it's not happening it's the solenoid or the starter. Very rare that the starter isn't grounding, but guess what, that can happen! Not seen that myself but saw it with an alternator. Solidly bolted on and didn't ground. On that, ( stuck 310 Case Track loader), I added a ground wire on the Alt. just to get it out.

Like on a battery terminal, a thin hard crust can develop which is an amazing insulator.

 

I feel like you might be right. If I don't get a better suggestion by this evening I'm going to just install the new starter and keep my fingers crossed.

Thanks for the input.

 

You should be doing a voltage-drop test between the batter positive terminal and the starter positive terminal (when attempting to start). Look up "voltage drop test" on youtube for more information, some of which specifically talk about starters. But testing for voltage drop is a general concept that can be applied to anything. But the symptoms you are mentioning sure do sound like voltage drop to me (meaning you have resistance between the battery and the starter, but it doesn't really cause a problem until you try to run the full amperage through it, so it doesn't show up easily on basic lamp/meter tests).

 

Alright, everybody. I'm headed out to swap the starter out.

 

Boom! He lives!

Thanks again.

 

I ohmed the main positive lead from the battery post to the starter post and it showed no resistance (I'm running 2 gauge with copper lugs).

 

The following video explains exactly why a simple ohms/resistance reading doesn't rule out the problem. He specifically uses a starter motor to make it clear. Given that your starter tested good, you very likely replaced a good starter. It was your connecting/reconnecting that might have solved the problem.

Either way, I'm glad you are up and running!

 

Good info.

Prior to replacing the starter I removed it, cleaned the area around the bellhousing where it mounts, scrubbed the binding posts on the starter to bare copper. Then I took it in to have it tested, then I reinstalled it. Then I replaced the 4 gauge supply wire with a 2 gauge with soldered and crimped copper lugs. Then I did all the grounds. Then I replaced the trigger wire. Then I replaced the starter relay (that silver box by the battery). All of that did nothing to remedy the problem. I replaced the starter and it worked.

I'm pretty sure it was the starter. I really wanted it to be something else because the starter was expensive but I feel like I explored every possible cause.

 

It was the starter. Had it ever been covered in engine oil?

 

It's lived under the filter adapter (or what I like to call the "oil distribution center") for the past 10 years. So, yeah, it had definitely been exposed to some stray oil.

I replaced the o-rings in the adapter when I did my motor mounts and cooling system last month, though, so my new starter should stay much cleaner!

 

The old oil leaks killed the starter.

 

Sounds like you were pretty thorough about it.