Speedo dropping on motorway and slight juddering

[Anothersmith]

Hi Guys,

Just wondering if anyone has had the same/similar problems.

On the motorway (hasnt happened below 70) at some point in the journey the speedo drops to 0 for usually the whole journey until I come to a stop and pull away again, then it has been fine so far until I get up to 70 ish again where it is temperamental.

Also in higher gears at lower revs the car has a slight judder as if misfiring or skipping a beat. And before you say it, no I am not running the engine to basically a stall point. For example it happens in 4th at about 25-30mph when you put your foot down.

Plugged a diagnostic machine in and it says knock sensor issue. However every thread I have read on here points to it being the speedo sensor. Can anyone shed any light? Going to re-diagnose tonight as last time I deleted the code to see what happened and it still carried on.

Thanks

(put this in here as well as in faults/problems as someone may know)

 

[R-Sport.]

Probably the speedo drive.
It will just keep getting worse- at least your miles wont go up

Cheap to replace.

 

[Nick172Cup]

Speedo sensor on top of the gearbox for definite, bit fiddly if you've got the standard airbox in place. Tops an hours work if you can hold a spanner.

Sensors normally cheap to buy second hand on here.

 

[r0ss172]

Your speedo issue will be the sensor attached to the gear box called the speedo drive if my memory serves me right. I had this problem on my 172 cup, not sure they use the same technology as the ph1 though.

Your second issue im not sure, where are you based? dependant on that i can advise you of which specialist to take your car to so that you can get it looked at properly. Who knows though, one of them may pop along on here and help you out.

On another note you should pay a subscription fee and have full access to all the guides etc which would help you with any queries in the future :race:

 

[Anothersmith]

Thanks guys, much appreciated, will replace the speedo sensor first and see what happens. Watch this space!

 

[Anothersmith]

Will this do it?

http://www.ebay.co.uk/itm/SPEED-SPE...o|Cars+Type:2.0+16V+Sport&hash=item4d061c998d

 

[DannyR]

The sensors are cheap from Renault if I remember rightly. I'd buy genuine.

 

[Anothersmith]

The sensors are cheap from Renault if I remember rightly. I'd buy genuine.

Am trying to get one delivered for tomorrow as I have time at the weekend to do it. Based on GSF Car parts and other sites like that that are supposedly cheaper than manufacturers they are selling them for 20 quid plus

 

[DannyR]

They maybe cheaper as a pattern part but will have less chance of working!