Club 80-90 Forums

Hi guys, getting great help here as usual but i more or less ended up hijacking someones thread unintentionally so i said i would start my own.

Basically the issue is, turn the key and i can hear the starter whirr away but the engine doesn't start. This might happen a few times and then the engine will start no bother, or the engine will start up first time no issue. 1.6 D by the way, non turbo.

So today i took out the starter motor to see was there wear on the starter pinions and there is not, it turns nicely by hand as well. So it was suggested perhaps that some of the flywheel teeth ay be missing, but the position the flywheel is in now is a position that i was getting a starting issue with this morning (hence me getting so fed up i decided to do something about it) and as you can see in the photo the teeth on the flywheel are fine, so i don't think that is the problem.

So without being able to see any physical defects to the starter i looked at the wires. I found slight corrosion on the wire from the positive side of the battery to the solenoid, when i was doing continuity tests only some parts of the ferrel would read continuity while other parts didn't, so i have cleaned all that up now also and getting good continuity throughout. So a question here would be, would corrosion on the starter cable inhibit the amount of current reaching the starter? But enough could still reach it to close the solenoid and engage the pinion but not enough to start the engine?

Also on the shaft with the starter pinion, there is a ring thing (sorry don't know what is is) that wiggles freely enough? Just wondering is that an issue? you can see it in the photo below.

Is there any bushings etc that can be worn on a diesel starter motor that could be causing the issue.

It was also suggested that maybe the battery was draining, measured it this morning and it was 12.8, measured it last night when i was having the issue and it was 12.3, the battery is 3 or 4 years old so maybe time to replace, however this issue has been happening for over a year but only in the last 2 or 3 months has been getting bad and particularly in the last week where it can take up to 45 mins of trying before it starts, as i said it doesn't happen every time.

If i have to buy a new starter that is fine, no issue with that but i don't want to buy a new one and find i still have the same issue. Any other tests i can do on the starter while it is out to prove it is working ok?

Ment to say its a bosch starter motor, i cant see a model on the label but i can see it says bosch, anyways of confirming solenoid and motor work while the starter is out?

Your problem is most likely to be the one way clutch in the pinion unit. There may be dirt in the clutch, or it may just have got a bit rough. When working correctly, the pinion should rotate easily on the shaft one way, but not the other.

I had the same problem, so bought a new pinion unit complete, but then washed the old one out in paraffin, then oiled it, and it has been OK ever since. The starter is a bit awkward to take apart, so depending on your level of ability, you might want to take it to a repair specialist.

If you decide to do it yourself, I'll try to give you some pointers.

[E D I T] removed part number because it doesn't look like yours![/E D I T]

Would dirt in the pinion clutch stop it from coming out and engaging the flywheel? I would be handy enough at giving things a go so taking it apart I would muddle through alright. Cheers for offer of help I appreciate it. The pinion does rotate one way and not the other.

You just me thinking as well maybe the pinion spins(that is what I hear) but the solenoid isn't engaging and pushing it out to catch the flywheel.

I would be inclined to give the starter a good clean, its probably bone dry, some lube will help, diesel engines are much higher compression than petrol engines therefore the starter takes a good hammering, try whats been suggested and check your earths but start looking for a replacement as bump starting a diesel t25 is going to be bloody hard.
If you haven't already put the starter back in can you take a photo of the bell housing where the starter fits to help me out on my thread regarding the new starter I have installed. the photo in this thread just misses the area I could do with a look at

Will do. Will get it in the morning and post it up for ya no bothers.

pleasestartnow wrote:Would dirt in the pinion clutch stop it from coming out and engaging the flywheel?

It goes something like this...................The solenoid uses a spring to push the pinion along a spiral groove towards the flywheel. If the one way clutch is stiffer than the spring, the pinion won't move forward without trying to rotate the armature which is heavy. The solenoid contacts will close, and the motor will start to run before the pinion has engaged.

Cleaning up the one way clutch has been a complete cure for mine over ten years.

Thanks for the response Colin.

Is there a guide somewhere for taking the starter apart to clean? Tried looking on the forum and couldn't see any.

There's exploded diagrams on the parts websites like etka, which are useful.
http://www.oemepc.com/vw/part_single/ca ... 888/lang/e" onclick="window.open(this.href);return false;
My recollection from taking my JX starter apart was:
Disconnect the main power cable from the solenoid to the starter
Remove the solenoid from the starter
Romove the Small cap from the forward end of the starter and slide out the retaining washer.(25 and 18 on the diagram)
Unscrew the two long bolts that go down each side and hold the entire starter together.(21)
Then you can see the brush holder plate (4)
Carefully remove that, catching the springs and brushes as the spring out. Replacement springs that match really well can be found on eBay or even in those variety packs of springs sold by the likes of Draper in your local hardware store.
Withdraw the armature (17). Can't remember if the pinion came out with it.

Could I add to RogerT's excellent explanation just a couple of things.

1. The little spring ring on the armature shaft is the key to getting the pinion off. IIRC it can be a bit fiddly to remove.
2. Getting the armature back in the brush holder can be a nightmare if you don't know how. You can hold the brushes back temporarily by hooking the curly springs not on the top of the brushes but pressing on the side of them. Then when the armature is in place, use a small wire hook to fish the springs on top of the brushes where they belong.

And putting it back together...

https://club8090.co.uk/forum/viewtopic.p ... 2#p8176894" onclick="window.open(this.href);return false;



E. D . I . T sorry Colin, not wanting to appear smug, I hadn't read your contribution through. But I was VERY pleased with my neat trick with the socket!

RogerT wrote:And putting it back together...

https://club8090.co.uk/forum/viewtopic.p ... 2#p8176894" onclick="window.open(this.href);return false;



E. D . I . T sorry Colin, not wanting to appear smug, I hadn't read your contribution through. But I was VERY pleased with my neat trick with the socket!

Quite OK. I realise that my little trick might actually be for the older type brush springs, so can probably be ignored. Yours looks like the correct little trick. But you definitely need one or other of these littlle tricks for any starter! In my defence, it is ten years since I did it.

Great help folks! Really appreciate it. Sourced another starter and then going to play around with the old and sort it out so I have a working spare for the future. Want to get on the move ASAP and start enjoying the summer. I know if I start tinkering with the old starter I may end up fla-ing it altogether.

Hope when the new one gets installed that that sorts the issue!

Cheers for all the help and advice. Will probably be back in tears in a week for help with something else haha

Installed new starter motor and so far no issue. Few places where it always seemed to not start before, such as outside the local shop, it now starts no bother (well so far, i am probably jinxing that now

Going to try and take the old one apart now and sort it out so i have a spare.

Thanks again to everyone for helping, really appreciated it.