Starter Oddity

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
This starter has about 7k miles on it.

This morning when I was already running late for work, I turned the key, got the click, then nothing but the whirring of the starter motor spinning. Nothing happened when I turned or pulled the key, it just kept going. So I ran into the garage and got a wrench to quickly pull the positive lead off the battery.

I waited for the motor to stop, then reattached the lead. There was another starter click, like the solenoid, then all was normal. So I turned the key, and it started as normal.

I'll report again on what happens when I try to go home from work, but.... ????
 

javelinadave

Administrator
Staff member
Next time it happens tap the front of the starter with a hammer or something hard. Nine out of ten times that will fix your issues.
 

NPT90

Well-known member
Next time it happens tap the front of the starter with a hammer or something hard. Nine out of ten times that will fix your issues.

Bad advice... likely the main battery feed from the starter lug has gotten loose and is grounded against the starter.

You will hear a whirring of the gear spinning even as it's not engaged in the flywheel.

Depending on your engine they can be a PITA to get to, it might seem intermittent but it will keep happening... ask me how I know
 

RDavisinVA

Technical Excellence Contributor
This starter has about 7k miles on it.

This morning when I was already running late for work, I turned the key, got the click, then nothing but the whirring of the starter motor spinning. Nothing happened when I turned or pulled the key, it just kept going. So I ran into the garage and got a wrench to quickly pull the positive lead off the battery.

I waited for the motor to stop, then reattached the lead. There was another starter click, like the solenoid, then all was normal. So I turned the key, and it started as normal.

I'll report again on what happens when I try to go home from work, but.... ????

You have a bad ground that is causing the starter to build up current in the armature and burn the solenoid contacts together.

Next time it happens tap the front of the starter with a hammer or something hard. Nine out of ten times that will fix your issues.

This is not altogether bad because it is the quickest way to jar the starter enough to break the burnt contacts in the solenoid and end the stuck starter rotation.
 

NPT90

Well-known member
I mean, all things equal, how would a bad ground cause this? A bad ground would give you a click not the starter spinning.

Also the starter is basically new, not saying a bad ground wouldn't cause intermittent issues but the most likely culprit is still the Main battery lead working its way down to the side of the motor casing causing current flow and the spinning armature he described.

Basically I had the exact same thing happen, Occam's razor sort of applies here, last thing touched was the starter motor lug.

The only thing that clicks before ignition could be the ignition itself or an unrelated relay, since you energize the start relay when you turn the key when would you have an audible click until ignition?

https://www.youtube.com/watch?v=n-RzcsdFoRQ
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
Bad advice... likely the main battery feed from the starter lug has gotten loose and is grounded against the starter.

You will hear a whirring of the gear spinning even as it's not engaged in the flywheel.

Depending on your engine they can be a PITA to get to, it might seem intermittent but it will keep happening... ask me how I know

I was kind of thinking the same thing, but wasn't sure. Especially since it happened only when I turned the key. I'll not be able to do anything about it here at school, but when I get home I'll check everything this evening.
 

NPT90

Well-known member
I was kind of thinking the same thing, but wasn't sure. Especially since it happened only when I turned the key. I'll not be able to do anything about it here at school, but when I get home I'll check everything this evening.

That's exactly how mine behaved.

If you have the truck with you and its a 300TDI you can visually inspect it more or less with a flashlight.

I basically had it happen a few times then it seemed fine, once you engage the starter and open the contacts it's possible the current continues to flow. While it could be the solenoid its just the least likely culprit given the relatively new starter in your vehicle.
 

rocky

NAS-ROW Addict
Rather than guess why, lets pull the starter and take it apart.....Do you have a spare one handy?
 

NPT90

Well-known member
Rather than guess why, lets pull the starter and take it apart.....Do you have a spare one handy?

I mean can't we just play armchair mechanics all day?

I only strongly suggest that lug because I have run into it several times in the past 4 months or so. It cause intermittent no start issues and battery charge issues on 1 truck and caused the same symptoms described here on my vehicle.
 

RDavisinVA

Technical Excellence Contributor
A bad ground will in fact cause this issue.
I left the ground strap off the transfer case during a transmission swap.
When I started the vehicle, the starter barely turned and as the flow of electrons built up in the armature winding and pulsed through what ever ground it could find, it caused the solenoid contacts to burn together.
I had to disconnect the battery to get it to stop.
Then removed the solenoid and sanded the burnt area and reassembled with the ground strap reconnected and all worked fine.
Remember an electrical device will try and draw whatever current it needs to keep working and complete a circuit.
With a bad ground, it will try and draw more amps to spin and thus burn the solenoid contacts as it tries to keep spinning.

It really doesn't matter if you believe this or not.

BUT

After you check and clean the burnt solenoid:
Try connecting a pair of jumper cables from the negative battery post to the starter housing and see if the starter works normally without touching the engine ground and report back.
There is only one way for a starter to keep spinning with the key off and that is to have stuck solenoid contacts (provided the ignition switch is working properly).
And the most common cause of burnt contacts is bad grounding.
 

Napalm00

Technical Excellence Contributor
Had a similar issue turned out to be the internal Bendix positive wire insulation had rubbed through and was partially grounding on the starter case.
 

NPT90

Well-known member
There is only one way for a starter to keep spinning with the key off and that is to have stuck solenoid contacts (provided the ignition switch is working properly).

What I really don't understand is the penchant to be ignorant of other possibilities.

I patently agree that a burn out solenoid can cause what is described herein. I also acknowledge that a weak ground could have cause said fault.

However if the installer didn't put the stop nut on first (which was the case with my starter) then ABSOLUTELY the vibration of the engine start would cause the contacts to touch and run the starter motor INDEFINITELY.

Just because you haven't seen something doesn't make it 'impossible'.

Simplest explanation here is that C179 is missing the backing nut and the vibration of the engine has allowed the contact close enough to the housing to allow either arc (with the added current of the starter solenoid) or enough contact to spin the motor.

C179-location.jpg
 

Napalm00

Technical Excellence Contributor
yea i struggled with it for about a month with it randomly not starting. I got really really good at roll starting it and parking on hills...then i broke down and bought one of Roberts Israeli starters...its been great.

Turned out to be an internal wire tho, could only see it when i took apart the starter case
 

RDavisinVA

Technical Excellence Contributor
What I really don't understand is the penchant to be ignorant of other possibilities...

If what you are trying to convey is that the lugs were loose and allowed the positive cable from the battery to contact another lug and jump current to spin the starter... I don't believe so, because the starter didn't randomly start engaging, it was brought about after the key was turned on and then kept running when it was turned off.

The scenario you describe would likely start spinning independently of switching the key to the start position.
 

RBBailey

NAS-ROW Addict
Callsign: KF7KFZ
Three start cycles this evening and no repeat of the problem. I'll check all connections and keep an eye on it.
 

Napalm00

Technical Excellence Contributor
FWIW this is one of major reasons I went to a 100% Vband connection exhaust. No gaskets, no rusted bolts, 5 min and the downpipe is removed giving complete access to that side of the engine.

you can do a starter in about 20 min total
 

RDavisinVA

Technical Excellence Contributor
FWIW.
This is one of the reasons I went to the GM 292 engine conversion.
2 bolts from underneath.
8 minutes to completely change the starter and that counts walking back and forth to get the tools.
The other reason is that diesel is now $0.98 more expensive than regular gas in my neighborhood.
 

NPT90

Well-known member
If what you are trying to convey is that the lugs were loose and allowed the positive cable from the battery to contact another lug and jump current to spin the starter... I don't believe so, because the starter didn't randomly start engaging, it was brought about after the key was turned on and then kept running when it was turned off.

The scenario you describe would likely start spinning independently of switching the key to the start position.

I think I accurately conveyed my position, I still think it's the lug, in my case the vibration of the start sequence was enough to bump it against the starter solenoid housing. When I turned the key off the motor kept spinning even though the solenoid clearly disengaged. It was intermittent and hard to reproduce, yes it would logically follow that if this lug making contact it would always make contact however I found, at least in my case, the act of yanking the positive lead from the battery while the starter was seemingly 'running away' was enough to break the contact between the main starter lead and the starter housing.
 

RDavisinVA

Technical Excellence Contributor
Three start cycles this evening and no repeat of the problem. I'll check all connections and keep an eye on it.

Looks like a lot of us have shared our opinions based on experiences with great conviction.
You just have to love the differences... and all among friends!

Share the news if anything further develops.
 
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