Won't start - knackered starter motor?
Posted 07 April 2010 - 20:31
My Octavia 1.8T (4x4) won't start. When I turn the key, the voltage plummets to the point where controllers get confused (all the dash lights dim or go out, the door lights go out and the central locking fires) and the starter fails to turn the engine. I know the battery is fine because everything works as expected - included main beams - before and after starting attempts, and jump-starting has made no difference. I'm thinking it sounds like a short circuit in the starter motor.
A couple of days ago I had the secondary air pump off to replace the worn out rivets with bolts but it worked fine after that (and I can't imagine I'd have done any electrical damage in the process).
For ages (months or years) it's made a funny screwy sound a second or so after starting, for about a second, but I'd always assumed it was the air conditioning clutch engaging. Can anybody else confirm that this noise either is or isn't air conditioning (or starter)?
How difficult is it to get to the starter motor? I have a Haynes manual to hand and it sounds as though it's underneath the battery and not too deeply buried. I'll have a look in the morning when it's light but wondered if anybody had had a rummage around those parts before.
Thanks in advance,
Posted 08 April 2010 - 07:56
Pop it off and give it a good clean up. The "funny screwy sound a second" is probably the motor failing to withdraw quick enough, and is a quite common issue.
Try the starter motor on the ground, but be careful they are rather violent beasts....
Posted 08 April 2010 - 08:26
I've been meaning to replace mine but they're something like £90 which seems a bit much just to stop it screeching in the mornings!
Posted 08 April 2010 - 09:44
Posted 08 April 2010 - 11:20
Update: I've taken the starter motor off and tested it. It didn't work as a unit so I disassembled it. The motor itself is fine. The problem appears to be with the solenoid.
On the end of the solenoid are two large connectors, one going directly to the battery (+) and one going via a short braided cable to the starter motor. When the solenoid engages, it presses a switch inside it to connect the two terminals together, thus connecting the motor to the battery. However, on mine, the motor connector (solenoid "output" if you like) is also shorted to earth. This explains the voltage drop when the starter was engaged.
Does anybody know whether it's possible to replace just the solenoid or whether the starter and solenoid come as a pair? I've heard estimates for the pair between £90 (above) and £230 (in another thread, admittedly for a diesel).
Posted 08 April 2010 - 13:04
There are 3 different part numbers for the body of the solenoid unit though so if it has a part number on the one you've got that may help?
Posted 08 April 2010 - 14:29
Cost me £110+vat from the Skoda dealer.
But GSF sell non-OEM ones for £110 including the vat.
Up to you really. Skoda trust me so I didn't have to pay the extra deposit for returning the old unit, GSF wanted an £80 deposit or something silly.
Very easy to change, and now I'm not embarrassed to start my car!
I'd be impressed if you could get hold of the individual bits.....
Posted 08 April 2010 - 14:50
It looks as though it may be possible, in principle, to buy individual parts but noboody around here stocks them and I need to get home so it's a whole starter. The options (all for reconditioned units and all inclusive of VAT) were:
- £154 from Skoda
- £110 from GSF
- £79 from the northerner down the road who services my Dad's car and gets trade prices for parts
The latter won! It will be installed as soon as it arrives - any time now.
Posted 08 April 2010 - 19:50
Also took the opportunity to clean and grease all the electrical connectors - there are three earth points under the battery and they were all getting a little bit grubby.