Starter Problem

[Lowrange2]

So, I'll do my best to describe this issue. Read closely.

I've had zero problems with my starter in the past.
93 Sport 4.0 auto

I'll make a video if it helps.

Yesterday my water pump went out. I towed it back home and replaced the water pump. When I started the engine to back it off the trailer the starter makes the same sound a starter will make when you try to start it while it's already running.

It turns over and starts fine but makes the grinding noise for a split second in the process of doing so.

Turn the key on, turn key to the start position, the engine spins over just as it should with no sounds. From the time it takes my brain to register that the engine has started to the time it takes for me to let go of the key it makes this sound. It makes this sound for maybe half a second. If I turn the key to the start position again while it's running it makes the exact same sound, obviously. Once I let go of the key it no longer makes this sound and runs perfectly fine.

My first thought was that the bendix were bad in the starter so I replaced the starter. Same issue. Exact same symptoms.

I've had people tell me that the ignition switch is sticking but I'm certain that's not the case. It springs back quickly and stops making the sound as soon as I let go.

A starter shouldn't work that way. Once the engine starts spinning faster than the starter, the bendix should retract from the flex plate immediately via the reverse threads in the bendix. For what ever reason it's not doing that.

WHY!?

Everyone else I've talked to about it says to just get used to the sound. That's not happening.

Grrr!

Thanks, Andy

 

[userbmx1315]

time to buy my jeep, problem solved hahaha,
to tell the truth, i have no idea. if its a new starter then try cleaning the ignition with di-elect cleaner stuff.

 

[Lowrange2]

But even if it's that the starter should retract the bendix as soon as it starts. It wasn't doing this at Gulches. It started doing it as soon as I backed it off the trailer yesterday.

It's gotta be something simple. At least it does it everytime so I can diagnose the issue.

 

[jeeperjohn]

Maybe coolant got into the electrical connections somewhere and is causing an intermittant short.

 

[Lowrange2]

The switch seems to work very consistently. Doesn't seem like an electrical issue to me. How could I go about checking that?

 

[Lowrange2]

This has happened to someone... That someone needs to read this.

 

[jeeptech1]

i would check the ring gear on your flexplate for any bad teeth.

 

[Lowrange2]

Teeth look good. It does it everytime no matter what part of the flex plate its on.

 

[Lowrange2]

How did I manage to post this in Mod Tech? I could have swore I put it in OEM Tech.

I pulled the starter and checked the flexplate all the way around. It looks brand new. Straight as an arrow and all teeth are in excellent shape.

I'm surprised how well it looks after 30,000 starts.

Next?

 

[Non-StopXJ]

It sounds like the starter gear isn't fully engaging/disengaging at random times, when it is pushed out to mate-up with the flex plate gearing.

Could there be a ignition wiring short near the starter, or maybe a really small section of gearing worn out on on your flex plate that would randomly cause the problem? I'd double check all the easy stuff first before dumping more dollars on it.

 

[Lowrange2]

This would be so much easier if I could physically put the jeep in the thread.

I could see a short becoming a problem all of a sudden but I don't think the gearing would have developed so quickly. It does it every single time I start it. Exactly the same way everytime. A short shouldn't act quite like that.

 

[cal]

inspect your bellhousing for cracks or other damage.

 

[Lowrange2]

I plan to climb back under it tomorrow and clean the gunk off. Ill report back.

 

[Mesh]

I have the same problem. At first it would do it once every couple of months. After about a year it got worse and it was doing it about every week. Then it did it three times in a row. I replaced the starter with a new unit not a rebuild the problem is mostly gone so far it's happened once in the past 3 or 4 months. My next step is the flex plate but it's not irritating me enough.

Replace the starter and flex plate with new parts and I think the problem should go away.

I was re-reading your first post and maybe it's not the same problem. Mine does it right when you turn the key and starts fine after you turn the key again.

 

[Lowrange2]

Yeah, mine does it between the engine actually firing to the time I let go of the key. I've got at least 4 ase mechanics stumped over this.


And yes, it irritates me that much.

 

[t-frady]

Take back to gulches lol

Exchange starter the red jeep prob just a bad starter bendix prob getting stuck or solenoid not reacting fast enough

 

[Lowrange2]

The problem IS the Red Jeep! The gold one is fine.

It's got a new starter on it now... :/

 

[t-frady]

U check relay?

 

[Lowrange2]

Relay is good.

I just got back from several different mechanic shops in town. They seem to think that the starter is getting in a bind with the flex plate and hanging up for a second before it lets go of it... They say that it's either due to loose bell housing bolts or torque converter bolts. I'll be checking both of those things this afternoon when I wake up...

Then I gotta start figuring out how to replace the rear main. It's starting to leak more often. Fun.

 

[Lowrange2]

Alrighty.

So, anyone who said it was electrical gets a cookie.

I don't know why I didn't do this sooner...

I got under there and pulled the starter back off, pulled the inspection plate and checked everything for tightness. Everything looked great. The only thing I saw was that the flex plate had a small bur all the way around the start side from wear. Didn't seem bad enough to cause the problem.

Sooo, while I had the cover off I wanted to spin it over while I was under there. I put the starter back on without the inspection plate, had my wife sit in the Jeep on the brake and ready to cut it back off when It started. I bypassed the ignition switch by shorting the switch wire on the starter and it started perfectly with no grinding. 10 times in a row. Then I got out from under the Jeep and started it with the key and it grinded like hell.

The problem is between the key and the starter. So, should I just jump right in and replace the ignition switch or is there anything else in the circuit that would have a poor contact?

The ignition switch and starter relay. Is there anything else other than wires? Any other parts that I can throw at it before I start chasing electrical grimlins?