Thread: Starter motor 300tdi

never pulled one apart......had to replace mine a few years ago

Hey Mick. Not sure on your weather but after a few cold days mine was not starting to well. It sounded as if the battery was sick (tested and shown fine however so thought maybe the starter) but then a few days later it was fine and now has no issues. It's been strong for over a month now.

I'd stick it out for a little and see how it goes unless your sure it's on the way out.

Xav.

Mick, it's a diesel and it's winter...

Make sure your battery terminals are clean inside and out and coat them with something like petrolium jelly or battery spray.

You can buy a battery terminal cleaner that is made by CRC but I find that hot water (boiling is better) and baking soda.

It only takes a little bit of acid build up on the terminal to make the starter a bit slow to turn over as it creates a lot of resistance and with it being cold as Gav pointed out the amps it would be pulling would be higher so the result is a slow turning starter.

Failing that, pull it out, pull it apart and clean the mud out of it, but normally the get sticky if they are full of mud.

Bad brush contact also increases resistance and causes them to turn slow.

Theres a few things for you to try..

Originally Posted by wannalandy

Hi Guys , Have got a problem what i think is the starter motor . since i bought it the disco has started fine and have not had a problem but after taking Elmo out for his first run in the mud the starter has been slow to wind over .
All the head lights are fine and windows still lift up and down without a problem . Which makes me think it's the starter and not the batteries .
Any thoughts of what it could be? And what i could do to fix it . Thanks in advance .

In my experience, they don't really fail like this. They tend to just not work, rather than turning over slowly. Normally hitting them with a hammer will get you going a few times until it finally dies. I would be looking for a loose connection, bad or low battery, bad solenoid, or damaged cable. The windows and headlights will work fine while not providing enough power to turn over fast.

/Damien

^^ all of the above, and also give the earth straps the same treatment, remove them and scrub everything with a wire brush till you have clean shiny metal.
I had similar problems recently and as it turned out the earthing was so poor it cooked the handbrake cable, I've also seen accelerator cables welded due to this.

Originally Posted by Disco300Tdi

Mick, it's a diesel and it's winter...

Gav , mine's a Diesel , and I have no trouble starting mine up in winter

WARNING DONT HIT YOUR STARTER MOTOR UNLESS YOU ARE PREPARED TO BUY A NEW ONE

They have permanent magnets inside that when you hit the casing they break and then when the starter turns for the next couple of starts it grinds the magnets into powder and you no longer own a starter that is worth more than scrap metal value as you cant just buy the magnets usually.

If you are really stuck and you have tried everything else like trying jumper leads and turning it over by hand with a socket off the crank a 1/4 turn to maybe line up a better spot on the ring gear etc then if hot try pooring cold water on it and then if that fails and you cant take it out or get a tow then give it a light tap with a piece of wood but I wouldnt do this more than once in an emergency.

People will say they have done it for years etc but considering a 300Tdi starter is worth $600 it would be better to drop the car around at an auto elec and get it fixed properly rather than risking stuffing it up.

Last time I had a starter rebuilt (that I didnt do my self) cost about $125 but it was for a Commondoor so it may be a bit more for a Disco.

Slow starting will be dirty terminals or earth to engine that is being more obvious due to the cold weather.

Either that or your battery is on it's way out or too small.