Have I got a 'weak' starter motor

[MidLifeCrisis]

Hi - Just replaced my starter motor (after the original gave up on me).
The new starter worked great for a day or so but now seems really weak and won't start the engine. It will turn over but seems to be doing so very slowly.
I thought at first that my battery was dead/dying so ended up replacing that but it's no better.

Here is a video (YouTube) of the starter out of the vehicle being run up (using the new battery and jump leads so that eliminates any of the vehicle wiring - I tried this with the starter on the vehicle too and it was as 'weak' so it can not be the vehicle wiring)

https://www.youtube.com/watch?v=uNscbmZD_3k

Does this look right to those who have experience of these things .... (I know its difficult to get a sense of speed on the vid but hoping you can give me your best judgement).

Cheers!

[itchyfeet]

well you shouldn't have done that, the starter should only be connected when it's in the vehicle becuse is has no bearing on the flywheel end, it runs in a bush in the bellhousing, you may well have knackered it.

bad starting can also be wiring including the main cable, trigger wire and earths.

[California Dreamin]

Unsupported armature (no nose cone) alert!

I wouldn't put much faith in that sort of 'non load' test anyway.

Likely cause is the oilite support bush has worn OVAL and needs replacing (about £3.00) or you have a poor earth or live feed..remember that under load a petrol starter can draw up to 160 amps so earths/battery leads and clamps have to be better than good to enable that kind of current transfer.

Martin

[MidLifeCrisis]

Ah - right!! Well, hopefully I've not made things worse (expensive lesson learnt!!!)

Could the oilite bush really be the cause of a 'weak' start? OK, I'll get onto changing that out (already read up on the job in the Wiki.)

Cheers for the input.

[California Dreamin]

Ah - right!! Well, hopefully I've not made things worse (expensive lesson learnt!!!)

Could the oilite bush really be the cause of a 'weak' start? OK, I'll get onto changing that out (already read up on the job in the Wiki.)

Cheers for the input.

Slow cranking is the main symptom of the oilite bush becoming oval and being forced partially out of mesh.
Don't rule out the need for a new earth on the gearbox. Personally I wouldn't bother fixing the existing gearbox nosecone earth strap but just add a completely new strap between the bell housing (starter bolt) and chassis (clean back to bare metal then paint afterwards) 450mm one of these:

http://www.autoelectricsupplies.co.uk/p ... ategory/27" onclick="window.open(this.href);return false;

Martin

[MidLifeCrisis]

Thanks Martin - will do both and see if that helps - sort of serves me right for skipping replacing the bush when the new starter went in.

[acw]

Sorry to jump in but the starter on my van is slow, but not all the time, tried a jump start to eliminate the battery but no change, is a worn bush the cause of intermitant slow turning starter

Andy

[California Dreamin]

Trouble is there are many things that could cause a slow crank.

Bush oval (petrol engines/manual gearbox)
Loose/insecure battery terminals
Weak battery, low electrolyte levels
Poor earths
Poor main feed
Corroded braided wire (between solenoid and starter body)
Poor contacts in the solenoid
Worn down starter brushes
insufficiently charged battery

And then there are things that can cause other types of starter faults:

Ignition switch erosion
Solenoid trigger terminal loose or wire rotten internally
One way clutch faults (on the starter)
Loose starter motor
Worn starter bearing
Worn out armature commutator

Martin

[ghost123uk]

I have added my take on running starters off the van to the wiki article on starters HERE

A note from Ghost123uk

Do not test your starter motor off the van !! - the cog end has no bearing inside, the bearing is in the bellhousing, it is that oilite bush that has been mentioned, and should be renewed whilst doing the starter. If you run the starter motor off the van, the insides (commutator etc) will thrash about inside the casing and likely damage the windings, the magnets, or both !

[MidLifeCrisis]

I have added my take on running starters off the van to the wiki article on starters HERE

A note from Ghost123uk

Do not test your starter motor off the van !! - the cog end has no bearing inside, the bearing is in the bellhousing, it is that oilite bush that has been mentioned, and should be renewed whilst doing the starter. If you run the starter motor off the van, the insides (commutator etc) will thrash about inside the casing and likely damage the windings, the magnets, or both !

You're welcome!!!
I'll get my coat .......

[ghost123uk]

You weren't to know, it should have been in the wiki to start with

[California Dreamin]

You weren't to know, it should have been in the wiki to start with

With other good advice like:
Don't stick your fingers in the spark plug caps whilst running
and
Don't check the tension of the alternator drive belt with the engine ticking over.

The WIKI would be full of 'The Obvious' sorry.....

Martin

[ghost123uk]

Bit harsh Martin

Many / most starter motors have bearings at both ends don't they, so can be run off the vehicle (not that doing so proves much I grant you )

See you tomorrow

[acw]

Hi

Thanks

battery ok as i had the same result with a jump start.
connectors and cables look ok but will have then off for a clean up.

is there any value in powering the starter directly from a battery or is it a recipe for disaster and likely to damage something?

let you know if i find a definite cause of the problem.

Andy

[Dazco]

As mentioned earlier replace the bush in the bell housing , easy and cheap job, cured my sluggish starter.