Starter motor teeth grinding noise?

[mike_nofx]

Hey all, I've just bought a patrol last night and have my first problem! (to be expected from a 20 yr old car) it's a 1990 4.2 petrol.

Ive started it a handful of times no problems, but today after work when I tried to start it, the starter motor just made a teeth grinding noise. Itried about 3 times and the same thing kept happening.
I then left it about 2 minutes and tried again and it started fine. It's been started no problems about 3 times since.

I had the same problem in my old Sierra, it only happened every 50 starts or so. It didn't really bother me because I knew being a manual, a push start is always plan b. But the patrols an auto, so it does bother me.

Anyone know what causes this? And how to prevent it?
Thanks

[TUFF MAV]

Probably find the teeth on the rin ggear of the flexplate are worn.If you pull the starter off you may be able to see the worn teeth.The only way to fix it is to pull the gearbox out.
Kyle

[mike_nofx]

So a small section of teeth may be worn?

In an auto can you just rock the car back or forwards a bit to get to a better section of teeth?

[RED60]

So a small section of teeth may be worn?

In an auto can you just rock the car back or forwards a bit to get to a better section of teeth?

The rocking won't work with an auto... you have to turn the motor using the "fan" belt. Motors tend to stop in several recurring positions when they are switched off mainly due to compression. The starter then tends to engage when starting in these positions more than the rest of the flywheel/flexplate. These areas wear more, so as other have said they can wear out...probably a new flexplate needed in your case. Also, as someone else said, you may be able to check by removing the starter motor and looking in at the flexplate. You may have to rotate the motor to find the dodgy spot...

[camaro67]

My GU 1998 is an auto and does the same, but on about once a month. On the other hand my brother has the same vehicle as me also and he has nothing but problems with his. He has turn turn every thing including the stereo in the car of to get his to start. Put a relay in the system and it improved it slightly. I beleive it my be his starter has a faulty clutch or something not the ring gear. I would try a different starter first. Easier than pulling the auto.

[mike_nofx]

It's done it another couple of times. It grinds first go, then on second crank fires up fine.

If it were worn/missing teeth on flywheel gear would it not fire up second try? (engine would be in same position, as would worn teeth)

after a bit of a google search, someone with a Toyota had the same problem and fixed it by cleaning the battery terminals. Is this possible, and if so, why?

Do the starter motors have reduction gearboxes?

[bigoll]

most likly to be your starter, it sounds like it is not throughing out properly and there for not meshing with ring gear on the flex plate. pull off your starter and give it a good clean checking electrical fittings to insure it has a good power supply and also make sure the starter gear is ok and slides freely on its shaft.

[Jaffa]

I have had the same problem in my GQ for quite a few years and finally decided to do something about it. The throw out "pinion shaft" was all gummed up, Ive cleaned it up and it slides alot better now.

Can anyone tell me if I need to grease the section with the arrow in the pic below (that was where it was all gummed up)

Thanks

[clm434]

i seriously doubt it will be missing teeth on the flywheel/ring gear. If there was then it'd be a noise you'll never forget.

[Navara-2.7TDi]

Are you certain it's a teeth grinding noise, or could it also be the solenoid throwing back and forth really fast? Often if the resistance in the circuit from the battery to the solenoid is high (worn out relay if installed, worn key barrel terminals, etc) and the battery is not 100% healthy the voltage drop when the solenoid engages the motor terminals is enough to reduce the available current to hold the solenoid "in" - the solenoid drops back out and the voltage increases again, and it's a cycle, solenoid goes in, out, in out at like 20-30hz and sounds like teeth grinding.

That would explain why it's so intermittent - a sign of an electrical problem.

[gumbs]

I have had the same problem in my GQ for quite a few years and finally decided to do something about it. The throw out "pinion shaft" was all gummed up, Ive cleaned it up and it slides alot better now.

Can anyone tell me if I need to grease the section with the arrow in the pic below (that was where it was all gummed up)

Thanks

I lubed it when I cleaned mine and it works well so I guess so.

The grinding noise is probably the solenoid not pushing out the gear far enough which probably means the starter is full of crap. Pull it to pieces and clean it up. Its about an hours work if your competent or a half a day if your an idiot like me. Its also probably worth your while to either run a bigger gauge or second cable to the starter while you've got it off. They were under wired from the factory.