Won't always turn over ?

[liamp_99]

Hi

Can someone help?

I have an intermitent fault, when I turn the key to start my S I will only get a clunk and the starter motor won't turn, I can try it several times and it won't work, then after a few go's it will turn over and start straight away?

Is this a problem with the solonied or is it the starter motor beginning to fail?

Or is this just a problem with heat, although this can happen from cold or when the car has been run?

Any ideas ?

[S3Paulo]

This happens to my S3 too.. for the moment I have learned to live with this problem. I wait a bit and then try again... eventually it spins over and fires up. There is a whole bunch of opinion on the causes of this fault...mostly dodgy connections from battery to solenoid and so forth. Disconnect all the main cables that supply the solenoid and starter motor and give them a good brush up with a wire brush...use vaseline/evolube when reconnecting...check also the battery terminals.

In my opinion its the rather stout copper contacts within the solenoid that have become burnt and pitted over time, giving a high resistance contact for the 12 volts that need to cross it and power up the motor. Hence the click from the solenoid operating.

Ultimately, I will probably just fit a recon. starter motor because the solenoid switch may be difficult to dismantle, in that it may be rivetted together. I have not looked close enough at it yet... the starter motor will have to be removed to do any work on the solenoid.

Of course I could just give it to my nice garage man and get him to fix it when the TVR fund looks a bit healthier.

If the solenoid can be dismantled it would be just a simple job of dressing up the contacts with a file.

[tvrgit]

From the symtoms, I would tend to agree with the solenoid diagnosis. You can strip the solenoid and clean the contacts, depends how much time you want to spend versus the cost of a new one.

[z_chromozone]

From extensive messing around with my own car I would suggest it is most likely an earth problem. Take all the earth strapping off and use emery paper to clean the contacts, and don’t forget (like I did), to clean the contacts of the strap behind the OSR wheel. Clean the positive contacts too and I bet it will turn over no problem

At least give it a try before removing the starter and spending money.

Z

[Colin Blues2]

Definitely worth checking both the main feed to the starter and the earth strap back to the battery.

If you are not getting a voltage drop across the battery when you are activating the starter then there is a resistance somewhere in that path that means the starter will not turn over.

Colin

[WonkyGibbon]

Take a look at this recent thread.
www.pistonheads.com/gassing/topic.asp?f=11&h=0&t=198047

Eventually when they get really knackered they won't turn over hot or cold.

As mentioned above, replace/clean earths and power feeds.

Refurb / replace starter.

Use a relay to switch the solenoid voltage from the battery rather than getting a "dropped" voltage from the ignition.

Fit a heat shield to stop it getting cooked in future (inexpensive and very easy - you can get alluminised cloth and heat resistant cable ties from RallyDesign for under £20).

Good Luck,

WG

[liamp_99]

I have cleaned all the earth straps, it hasn't happened again, early days yet though, I will let you all know the out come. In the mean time I will purchase some kind of heat sheild.

Thanks for the advice.

[SLB]

Had a similar problem, only really happened when hot usually after filling with petrol. Turned out to be corrosion in the battery connector ie where the earth cable gets screwed into the heavy duty connector. A good clean and she was fine.