speedo needle keeps jumping?

[kevin.s]

ive noticed that somtimes when i open it up a lttle as i change from 3rd to 4th or 4th to 5th, the speedo needle will jump up about 20 or 30 mph in a split second then drop back down to where it should be. any ideas on what thats all about? as i know the throttle responce aint that good lol.

 

[Rob]

Gearbox speedo sensor more than likely mate, new one is £20 from Renault, its ontop of the gearbox, you can just about see it looking down the back of the engine.

 

[kevin.s]

doesnt the speedo work off the abs on the 172`s?

 

[f0xy]

Depends on model/phase...

 

[kevin.s]

its a ph2 51 plate 172 non cup

 

[f0xy]

I always thought it was only 172 Ph1 and 172/182 Cup that had the speedo sensor in the back of the box (Cups due to lack of ABS obviously). Although, Blooooors 172 Ph2 had a speedo sensor in the back of the box, so im not too sure.

Its easy to check, lean over and look down the back of the engine. If you see a plastic sensor sticking upwards out of the back of the gearbox, it has a speedo sensor.

 

[kevin.s]

ill have a look when i get chance then, cheers.