Speedo Correction

[BigChris]

Following on from my topic in general discussions the other day.

I am experiencing a problem with the speedo, whereby i will be driving at e.g 50mph as per speedo, but in fact i am doing 57mph in real speed!! so the speedo is actually UNDER reading!

I took the car to renault today, and sure enough they calculated a difference in speedo reading to real speed by a 6mph under read!

They are saying that the actual reading from the gearbox up is fine, but when they actually get to the instrument main unit, this is where the problem is - they have quoted me £450 fitted for a brand new instrument unit!!

surely there must be a cheaper, or better way to simply "recalibrate" the speedo?

any ideas?

 

[_M_A_T_T_]

thats day light surely a cheaper way

 

[dick]

move the needle?

 

[lemonnobby]

just move the needle till you get it right? this is what i had to do with one when i fitted some dials to it.

 

[BigChris]

as you say matt - even if it means buying a second hand 172 cup unit from fleabay or the likes, anything is better than having 450 notes fly out of my pocket...

can you honestly just "move the needle?"

 

[dick]

ye lol,

 

[lemonnobby]

yea they just clip off mark where it was and reclip it slightly higher.

 

[BigChris]

wicked, ill give that a go this weekend then... how easy is it to get to the needle? do i need to crack anything open or does it just seperate with nuts and bolts. thanks, chris.

 

[steven.m]

all cars do that dont they. I compared mine to my Garmin satnav and its roughly a 10% difference with the speedo reading over my actual speed. My mate also got the same result in his car, as did my dad. Is there not a legal requirement for the speedo to overread?

EDIT: and its relative to how fast your going ie 30mph on speedo = 27mph on satnav, 60mph on speedo = 55mph on satnav etc

 

[BigChris]

steven, its not over reading though - this is normal

it is UNDER reading i.e. the speedo is showing me 40 mph when in fact my tom tom is saying 47 mph!

 

[tim124]

most cars over-read, car companies do it to cover their backs,

i think the original poster is complaining that his speedo is under-reading

 

[lemonnobby]

no normally they over read so you really want to go though a speed carmea doing 50 as per speedo but actual speed is 57mph, the dails come apart but its very flidly. The needles is tight to get off use the handel of 2 tea spoons and lift it of from either side so you get constant pressure.

 

[steven.m]

Apologies, I completly typed that wrong, I meant the opposite to what I've actually tyepd!

 

[BigChris]

no problem steven, just wanted to clear it up so people understood where i am coming from. Lemon, thanks for the advise - will attempt it this weekend... hopefully won't snap it

 

[lemonnobby]

Look at the threads for the LED dash change they might know better than me as you have to take it apart to do the conversion

 

[BigChris]

one other thing...

when i reset the average speed dial on the trip computer when i am doing say an average 30mph on the speedo, the average speed always comes back 6-7 mph over the speedo, so would that definately mean the needle just needed moving?

 

[MT AUDIO]

thats normal the average speed includes stopping time

 

[InSoMnIa]

if your to move the neddle you need to move it all the way around till it gets stiff the move it a little more to adjust the actual postion of the speedo

 

[BigChris]

i will have to do it by trial and error i think, and match it to my GPS, but allow for a little "extra" to be on the safe side... ill keep you posted with it.

Is there a good guide for dash removal?