new starter motor & battery but still got an "issue"

So after fitting a new battery and starter motor to my 300 tdi i am still enountering an intermittent starting problem

For 2 days after the new bits all was well until today

Started first time for trip of 5 miles but then after couple of hrs turn key get gearing screach from starter motor. Tried again and just got starter motor wirling no turn over or fire. Did this a couple of times.

Dipped clutch (no sure if this had anything to do with outcome) and tried again and started first time and has done everytime since

So what do you guys think to all of this....... Really appreciatd your help

Bad Earth or corroded Earth

put the black jump lead from your battery -ve terminal to the thermostat housing **make sure it will not fall off or get in th eway of belts fans when you start see if it starts any easier

Sorry should have said battery earth to chassis crimp and geatbox housing checked n cleaned, also had new earthing strap
Kind of at a loss

Are the problems you're getting now the same as what you were getting before replacing the motor & battery?

discobill said:

Are the problems you're getting now the same as what you were getting before replacing the motor & battery?

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No - previously started just clicked and did not turn

Now starter consistently clicks and turns - but has started to gear grind (presumably starter not fully engaging with flywheel) and then if you try to turn from position II to position III (without going all the way back to ignition off) starter spins away merrily to itself and goes not engage

Do 90's have a clutch switch which may have accounted for it starting OK with it dipped - or is this just an artefact of turning ignition off and restarting process ?

Thanks everyone

I guess that as you've looked everywhere else, the only thing left is maybe the ignition switch it's self maybe faulty. I've never heard of one failing before but I might be worth a try?

Sounds like worn or missing teeth on the starter ring.

Treworgey 90 said:

Sounds like worn or missing teeth on the starter ring.

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HI - do you mean missing teeth on the flywheel - or on the new starter motor ?

Cypermethrin said:

HI - do you mean missing teeth on the flywheel - or on the new starter motor ?

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The starter ring is around the outside of the flywheel.

Treworgey 90 said:

The starter ring is around the outside of the flywheel.

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I'm with you - is it an integral part of the flywheel (ie can it be replaced on its own or is it new flywheel and starter ring ?)

Thanks again

Take the starter motor out and get someone to slowly rotate the engine, using the crank bolt, while you inspect the starter ring through the hole. It might be easier to use a torch and mirror.
If it's knackered, you'll need a replacement flywheel I'm afraid, and you might as well do the clutch while you're at it.

Can't the ring gear be changed ?

I have done a couple in the past. You use a hammer and cold chisel to break the old one and remove it, they will crack quite easily if you put the chisel between two teeth and hit it a smart skelp. The new ring gear has to be heated as much as you can to expand it (boiling water, very hot oil or gentle blowtorch and thick gloves) then quickly, while it still holds heat, put it in place on the flywheel and "drift" it into place with a block of wood and a hammer, working in an even circular fashion, I have heard of some people chilling the flywheel in their freezer to help this, but I've never had to do that.

Usually if you are missing teeth, or they are badly worn, "rocking" the vehicle in a high gear with the handbrake off will move the flywheel enough for your starter to engage. So next time it wont engage, try rocking the vahicle in gear and if this makes a difference you can pretty much assume your ring gear is worn, but don't base your decision on only one or two tries. If it makes no difference then it's probably something else. Dirty solenoid contacts are common but they can be cleaned & re-dressed or replaced.

To test the solenoid, try using a jump lead from the battery +ve directly to the starter motor side of the solenoid (but please be careful that the vehicle is out of gear etc.) if this helps the starter to engage the flywheel as normal then your connections &/or solenoid would be the things to check.

R.