Car Problem... Please Diagnose!

[Stuuk1]

Hi all,

The car is bloody playing up... Seeming as I have next to no knowledge of this stuff I was wondering if you could diagnose it for me...

http://youtu.be/Ts21cK9TnmA

Is the starter motor knackered? It's as if something is spinning but not engaging?

Any help would be much appreciated

Edit: Apologies for my heavy breathing...!

[Mark_h]

If when it's not starting it's spinning but not "catching" at all THEN when it does start it's absolutely perfect, ie, not sounding flooded or lumpy then it may well be your TDC sensor. Especially if worse when hot. This tells the fuel when to fire. Google it up and find it, Will be somewhere in the bowels of the engine, probably just a couple of bolts. Chances are if it's intermittent then it's just swarf on the end of the magnet. Take it out, clean it up, shove it back in and see what happens.

I may however be completely wrong as it wasn't the most comprehensive of demonstrations and I know very little about anything.

[DJ123]

Does it do this more on cold days than warm days? After warm running as well? or after its gone cold?

[Red Herring]

It's a starter motor issue. Basically starter motors have a small gear that moves out and engages with the flywheel when you want to start the engine, and it then disengages once the engine is running so that the starter doesn't keep spinning when not in use.

This gear can be moved out in one of two ways, pre-engaged or inertia type.

The pre-engaged one uses a solonoid to move it out and as the gear engages a circuit is completed and the starter motor starts to spin. These are the ones that go click sometimes and nothing happens until you give it a smack with a hammer....
This doesn't sound like yours as the motor is spinning without engaging with the flywheel.

On the inertia type the gear is mounted on a bendix (a spiral on the shaft) so when you turn the key the starter immediately starts to spin and in doing so it flicks the gear out and it engages with the flywheel. Sometimes (usually in cold weather when the grease is a bit think and sticky) the gear doesn't fly out properly so doesn't hook up with the flywheel (can also happen if the battery is a bit weak and doesn't get things moving fast enough) and then you get the scenario where the starter motor is spinning, but not turning over the engine.....like what you got! Quick fix is to stop (like you did) and then turn the key again hoping that second time round it flicks out (like it did).

Check your battery, if that's OK then you probably need to have the starter off and lubricate the bendix properly.

[Biker Biggles]

Did I miss something?Sounds like it started up perfectly well to me,but if you want to "fix" it Im sure hitting it with a hammer would be good.

[Mark_h]

Sounded like it was turning over first time too. If the bendix was stuck I doubt you'd even hear the starter turning from inside the car.

[DarrenSV650S]

You two need new speakers ^

[Stuuk1]

Originally Posted by Red Herring

It's a starter motor issue. Basically starter motors have a small gear that moves out and engages with the flywheel when you want to start the engine, and it then disengages once the engine is running so that the starter doesn't keep spinning when not in use.

This gear can be moved out in one of two ways, pre-engaged or inertia type.

The pre-engaged one uses a solonoid to move it out and as the gear engages a circuit is completed and the starter motor starts to spin. These are the ones that go click sometimes and nothing happens until you give it a smack with a hammer....
This doesn't sound like yours as the motor is spinning without engaging with the flywheel.

On the inertia type the gear is mounted on a bendix (a spiral on the shaft) so when you turn the key the starter immediately starts to spin and in doing so it flicks the gear out and it engages with the flywheel. Sometimes (usually in cold weather when the grease is a bit think and sticky) the gear doesn't fly out properly so doesn't hook up with the flywheel (can also happen if the battery is a bit weak and doesn't get things moving fast enough) and then you get the scenario where the starter motor is spinning, but not turning over the engine.....like what you got! Quick fix is to stop (like you did) and then turn the key again hoping that second time round it flicks out (like it did).

Check your battery, if that's OK then you probably need to have the starter off and lubricate the bendix properly.

Fantastic explanation, thank you. Found a video on YouTube and will have a go at trying to find it. Shame as this weekend I'm away so can't do it for a couple of weeks.

With the above in mind, will it get worse? My guess is that it will... Otherwise I'll have to get the missus to take it to a garage tomorrow.

A new one only looks to be around £80 anyway!

[Stuuk1]

Originally Posted by Biker Biggles

Did I miss something?Sounds like it started up perfectly well to me,but if you want to "fix" it Im sure hitting it with a hammer would be good.

No, def didn't start, just a spinning noise... Should perhaps have taken the video with bonnet up.

[Red Herring]

It depends on what the cause is. It's usually one of these things that slowly gets worse and you don't notice happening until one day it doesn't actually engage, then for a while it will/won't, before finally the won'ts start to outnumber the wills and you have to do something about it. If it's only just started missing occasionally you'll probably be OK for a while...... or at least until the next wet cold night when you really need to get somewhere....