Starter Motor Fault

[Bassman 1]

Right,

 

Usual GTi starting problem.

 

Replaced earth leads, fitted new feed to the solenoid from the ignition.

 

Removed the starter motor and tried it off jump leads direct to the battery about a dozen times and it started every time, no problem.

 

Fitted it back to the engine, having cleaned up all the connections and it starts about once every 20 attempts. The solenoid is defnitely engaging as I can hear it quite clearly and the lights dim suggesting it is switching in the main feed to the motor and drawing a lot of current.

 

I'm a bit confused as to why it doesn't spin when under load, when it does actually go it seems to crank at a normal speed, suggesting that perhaps the battery is ok once it overcomes this intial problem.

 

Could there be a flat spot in the motor or dodgy brushes?

 

Plan is (when I have my enthusiasm back again) to swap out the battery with the new one in my 405 and if that doesn't work, swap out the starter motors as the one in the 405 has never missed a beat in 12 years. That should confirm the fault then.

 

Any other ideas before I pull the inlet manifold off again?

 

Rob

[steve@cornwall 100]

Right,

 

Usual GTi starting problem.

 

Replaced earth leads, fitted new feed to the solenoid from the ignition.

 

Removed the starter motor and tried it off jump leads direct to the battery about a dozen times and it started every time, no problem.

 

Fitted it back to the engine, having cleaned up all the connections and it starts about once every 20 attempts. The solenoid is defnitely engaging as I can hear it quite clearly and the lights dim suggesting it is switching in the main feed to the motor and drawing a lot of current.

 

I'm a bit confused as to why it doesn't spin when under load, when it does actually go it seems to crank at a normal speed, suggesting that perhaps the battery is ok once it overcomes this intial problem.

 

Could there be a flat spot in the motor or dodgy brushes?

 

Plan is (when I have my enthusiasm back again) to swap out the battery with the new one in my 405 and if that doesn't work, swap out the starter motors as the one in the 405 has never missed a beat in 12 years. That should confirm the fault then.

 

Any other ideas before I pull the inlet manifold off again?

 

Rob

 

Are the dowels missing that locate the starter?

[Bassman 1]

Are the dowels missing that locate the starter?

Good thinking. There was only one dowel that I recall when I re-fitted it. I could try connecting a jump lead from the body of the motor to an earth point if / when I remove the inlet manifold to see if that helps the grounding.

 

Thanks

 

Rob

[saveloy 8]

Are you sure it isn't simply a worn ignition barrel. I have this problem on mine. If I twist the key and hold it just before it's stop, then the starter is fine. Otherwise, it wo't transmit the whole 12 volts.

[Bassman 1]

Are you sure it isn't simply a worn ignition barrel. I have this problem on mine. If I twist the key and hold it just before it's stop, then the starter is fine. Otherwise, it wo't transmit the whole 12 volts.

 

Can't be the ignition barrel as the solenoid is pulling in every time I turn the key and the main feed is connected as I can hear it humming and the lights dim.

 

I will try swapping the motor from my 405 at the weekend, this should definitely give me an answer then.

[Bonzai 2]

get a multimeter out. measure the voltage you get to the solenoid at the brown multiplug under the dash, then measure the voltage at the brown multiplug on top of the gearbox. Mine was losinga lot so i spliced in a new cable from teh solenoid to the dash and now its perfect (touch wood quickly!!!!)

[Bassman 1]

After stalling for a week by playing with the 307 brakes I am going to fit, I have pulled the motor out again as it was refusing to start at all even though the solenoid is moving and the main feed is being switched on.

 

There is only one dowell as that is all that there can be so it wasn't the earthing problem suggested by Steve, although a good idea!

 

Going to see if I can pull the back of the motor off that houses the brushes. When I last looked the nut that holds the back plate on has a plate aroudn it with two raised tabs that stop you from undoing the nut. I presume I can just push these flat and undo the nut?

 

Rob

[ablister 31]

some starters require special tool to remove the casings (eg some valeos iirc) but should just be able to get the end casing off if it allows you.

 

Worth testing the starter with a bit of wood. Remove the starter and place in vice, get the starter to start by bridging the solenoid + positive conection and earthing it. When the pinion pops out and starts turning, push the bit of wood onto the teeth and it should still turn if ok or stop if faulty (worn bushes probably).

[Bassman 1]

Took it apart after a bit of faffing and it appears the cable that connects to the shell of the motor is knackered. It is obviously still connected, but perhaps when I am trying to start, there is not enough contact left and the higher resistance is causing the motor to not have enough grunt to turn.

 

Does anybody know how the wires are connected. They don't appear to be soldered and are covered in some red gunk. I assume this is to stop it corroding.

 

The brushes seem to have enough life left in them, but I would rather replace them if I can, although the one is also attached directly in the same way as the earth cable.

 

Rob

 

Case showing earth and one brush connection

 

Fooked

 

Armature

 

Closeup of brush connection

[Bassman 1]

Found a great thread on Aussie Frogs that describes the same sort of connections to the brushes and earth wire as I have. Apparently they are spot welded on rather than soldered as the lugs are aluminium. Looks like if I am lucky and have a stub of wire at the lug I can solder to that or it's off to an Auto Electrician to do the job.

 

Repair of an Mi16 starter motor

Edited October 6, 2007 by Bassman

[Bassman 1]

Well I got a new set of brushes and two springs for a fiver and I soldered the new brush on using a blow torch to get sufficient heat into the lugs and also soldered a new earth braid to replaced the knackered one from the photos.

 

Put it all back together last night and tested it with jump leads from the battery and all was ok. Which I expected because it worked fine on the bench before.

 

Bolted it in the engine tonight and it fired up first time, and then the second time and then the third time and then nothing...

 

... back to the same problem with the solenoid engaging but the motor doesn't spin.

 

I am pretty convinced now there must be a fault in the armature windings and I am getting a dead spot on the top of the armature, but being a numpty I didn't try and buzz this out before I put it all back together.

 

Starting trawling eBay for a motor tonight, at least I know I can refurbish the easy bits on a second hand motor for about £5 provided the armature is ok.

[Bassman 1]

Found a 306 1.9 DTurbo Starter Motor on eBay and managed to get it for a fiver! Picked it up this afternoon and whipped off the solenoid and cleaned it up and re-greased it.

 

Also pulled the back off to have a look at the brushes. Plenty of travel left so I just gave the armature a clean up with some emery paper.

 

Note: with the 306 starter, the brush pack and armature is quite different from the 205 GTi and the brushes contact horizontally and there are four of them. Which means when you pull the back of the motor off and pull it past the top of the armature the brushes spring out to full extension, which means it takes a bit of patience and a couple of screwdrivers to hold them all back in to refit.

 

Bolted it onto the GTi and Robert's your father's brother, it started with no problems. Being a diesel motor it seems to spin a little slower, but I had no problems. Let the engine warm-up for about an hour and keep turning it off and re-starting, but no sticking like before.

 

Problem solved, thanks for the advice and for once it wasn't the brown multi-plug.

 

Rob