crankshaft sensor

[Cavalier342]

Hey all. My crankshaft position sensor plays up a lot, especially when its cold, which makes the rev gauge read a bit higher than it should. Almost all the time when its cold too, When its ticking over, it can sometimes read 1200-1300rpm when the engine is perfectly idle. Anyways, today, for some reason, i had it in neutral and noticed the needle go totally insane, jump up to well above 2000, approaching 3000 and jump about in between. I was at the lights, so i restarted the engine, and it went back down a bit. Still does play up though. Now, my question is, does this mean it is on its last legs and what would happen if the sensor fails altogether?
Thanks.
Andrei

[Gaz]

its not your crank sensor
its your icv needs cleaning and possibly you need a new temp sensor

[Cavalier342]

Oh right. Well i only mentioned the crank sensor because i had fault codes flash up before regarding that, and it had the same issue.
Ok cheers anywho, i'll look into that.
Andrei.

[Gaz]

You sometimes get crankshaft sensor as a fault if the engine isnt running when you read the codes

[Cavalier342]

Oh right cool i see. So, does it do it any harm then or not?

[Gaz]

doesn't matter.