Intermittent Starter issue Starter spins but not engaging
 

I have a strange issue where my starter isn't engaging intermittently. Occasionally when I turn the key the starter motor spins but isn't engaging. Problem showed up yesterday after a 500 mile trip to visit my brother. Both of us were convinced it was a starter issue. My brother had a known good starter that I put in.... same issue. We tried to start the car. The starter motor spun but didn't engage the ring gear on the first try. No grinding or odd noises like the starter gear was hitting a bad spot on the ring gear. On each subsequent try, the starter engaged and the engine fired. The battery voltage is at 12.5 volts so it's not a low battery issue. Any suggestions on what to check? I don't want to be in a position where I stop to fill up with gas on the way home and have this pop up. We're going to try removing the starter and spin the ring gear while using a mirror and flashlight to look at the ring gear.

Like so many electrical issues, the grounds are the first thing to check. Then clean every starter connection. Does it do it when the car is cold or just after long trips and full heat soak?

Glen is right. Your battery connections are probably dirty. Take apart and clean the connections at the battery. 12.5 volts is low. A fully charged battery should be between 12.6 and 13.3 colts. Again, battery connections are the first place to look for poor charging. I had the same issue yesterday and thought I would finally have to buy a new battery but no! Cleaned and tightened the battery connections and I am spinning the starter at full speed again. Whooppee!

Something I forgot to mention. Yesterday when I got to my brother's house, we tried starting the car and it did nothing! Hit the key and got nothing from the starter. No click of the solenoid and the starter motor did not spin.
I'm going to take the transmission ground off and clean as well as take the battery connectors back off and clean well. I bought a scope from Harbor Freight and will be taking the starter back down to inspect the ring gear just for peace of mind.
Question: where is the ignition relay? I'm questioning with the way the starter did nothing on the turn of the key if I might not have a problem with a starter relay?

Thanks for the help guys!

Stone cold.

I had the same issue with a heat soaked Bosch starter. I took it to a local expert, he rebuilt it, new bearings, all fresh and happy. I drove it for a day in the heat, and it would just lock up from heat soak. Within 30 to 40 minutes it had cooled off to work fine. I could drive all summer for normal short trips under an hour and it always worked. Only when it was really heat soaked, as in 500+ mile trips did it lock up.

I just gave up on the Bosch starter and went to the High Torque starter, and it has been flawless. I really think the Bosch starter has some issue with too much heat, and it just locks up tight, no click, nothing. If you can pour water on it it will cool off pretty quick and work fine.

Glen,
I don't think it was a matter of heat when it would do nothing. The car had been sitting in the garage for about 3 hours and I would think would have had time to cool down. What is really throwing me off is that it will do it when it's stone cold. About 2 days ago I was under the car checking because the original starter (about 6 year old rebuilt starter that hasn't been used much since it's only a summer car) was acting funny. after checking to make sure the connections were tight and clean, and while the back end was still in the air, I tried to start the car and it did nothing. I took it off the jack stands and I don't know if the jostling from setting the car down off the stands shook something but it fired right up after just doing nothing. The car hadn't been driven for about 3 days prior to me checking into what was going on.
I did some research on the high torque starter last night while thinking of potential causes for this weird issue. It seems like it has to be an electrical issue since my rebuilt starter and the known good starter my brother had both acted the same way. I'm still going to pull the starter, slide the scope I just bought into the opening and see what the ring gear looks like just to eliminate that as a potential cause. Something catastrophic would have had to happen in the since I did head studs a few years ago because the ring gear was in perfect shape with no signs of rounded teeth or stress cracking.
I'll post back after I've done some more looking. I'm searching to find the starter or ignition relay in order to bench test it as well.

Update:
Brought battery in for load test. Good
Removed and cleaned transmission to chassis ground cable
Removed and cleaned battery ground
Cleaned Battery positive post and terminal
Cleaned Battery negative post and terminal

Tried to start... click and nothing more

Tested voltage at yellow wire to starter. Here's where it seems odd. The yellow wire had voltage with the key on. I thought this wire should only have voltage when the switch is turned to the start position. Am I wrong in my thinking here?

Next up:
Clean all grounds at intake runner
Remove starter and clean face of starter as well as the transmission housing for the starter.

Help me out guys. I need to get this thing running so I can drive it home Sunday.

do you have some kind of kill switch on the car.Look under the dash for the ignition wire plug if somebody put inline of the thick yellow wire a splitter connection ..

Ivan

Another place to look is the 14 pin connector in the engine bay. The yellow wire goes through there on its way from the ignition switch to the starter.

It's your starter. Get another one, not from your brother. I had that problem.

You're right.. in part. The starter that my brother has worked about 6 times..... and puked. The starter I had in the car (a rebuild) works as it should BUT the dust shield that also acts to center the the shaft for the starter came off and was inside the the housing preventing the starter gear from extending to the ring gear. I'll post pics later. Don't know if trying to start the car with the obstruction toasted the starter my brother had or what happened but we bench tested finding the gear extends out but with power to the starter motor, the starter motor does not spin anymore.
Again, I will post pics of the piece that came off of the original starter.

Go with the high torque starter.
I pulled my old Bosch starter apart (unsoldered it) and flipped the contacts in the solenoid. Worked for a while but then got intermittent again. The new high torque has been flawless.

Pics of what happened to the rebuilt starter. The what was once a round pice you'll see in the pics came off the head of the starter and was preventing the starter bendix from extending out to contact the ring gear. This piece would move out of the way allowing the starter to make contact and then move back into a position preventing the starter bendix from extending out. We found that it takes very little pressure against the bendix to prevent it from extending forward through testing the starter. You can see from the picture of the other starter where the piece that fell out should be. I should have the replacement starter today and will post back with results.

http://forums.pelicanparts.com/uploa...1558799143.jpg
http://forums.pelicanparts.com/uploa...1558799157.jpg
http://forums.pelicanparts.com/uploa...1558799169.jpg
http://forums.pelicanparts.com/uploa...1558799180.jpg

Made it home thanks to a $75 reman from an auto parts store.

Starter not engaging noises, causes, and solutions to anyone in need
 

I found this article that gave 7 sounds you can identify to find out what's causing your starter to not engage: Starter not engaging: What the sounds tell me?

On the occasion where the starter keeps spinning and makes a grinding noise as you start the car, you may have a:

1. Worn out Bendix, flywheel, or pinion gear with broken or worn-out teeth. A worn-out Bendix can result in the starter motor not engaging sometimes, which causes the grinding sound it produces. To fix the flywheel or pinion gear, it is advisable you contact the nearest service center.

2. An incorrectly mounted engaging mechanism which makes the Bendix spin too early or too late. This can be fixed by using a ratchet to rotate the crankshaft manually. You should also check the bolts and fasteners to be sure they are properly tightened.