porkflap
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- derbyshire
Hi, is it possible to re-calibrate the speedo on a 300tdi as mine shows 10mph less than you are actually doing! (checked with a gps device)
Chris
Chris
300tdi, sorry more questions!
- Thread starter porkflap
- Start date
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porkflap
New Member
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Yer i have tried that, and that seems to be ok in most things, also it seems a bit slow in the discovery!, is they andthing else that could affect it, the wheels and tyre's are just standard!
Chris
Chris
Felix
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- Dunfermline, Fife, Scotland
Hi there
Its quite normal for the speedo to be optomistic usualy by a max of 10%. This is a good thing as it keeps you under the spped limit when you are hovering close or just over. I have only seen Mercs run right on the money. 10 MPH does seem a lot though might be time to look for a new instrument pack or borrow one to see if its a problem with the head or the speed sender (not sure where that is yet) somewhere on the gearbox.
Felix
Its quite normal for the speedo to be optomistic usualy by a max of 10%. This is a good thing as it keeps you under the spped limit when you are hovering close or just over. I have only seen Mercs run right on the money. 10 MPH does seem a lot though might be time to look for a new instrument pack or borrow one to see if its a problem with the head or the speed sender (not sure where that is yet) somewhere on the gearbox.
Felix
porkflap
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Thanks, i think that sounds the best think to do scower the internet for a instrument pack and have the gearbox bit out and inspect it!
slob
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- Harrogate or London
i doubt that a faulty speed would cause the problem you describe. if any thing you would get an erratic reading, but from what you say its seems to be a steady reading just the wrong speed.
i don't know what diffs are available for your axles, or even if there is a difference in ratios between different engines, be it engine size or fuel type, if you say tyres are correct then i would suspect 'wrong' ratio diffs have been fitted at some time in an effort to get better mileage.
(usual disclaimer applies... this could all be bollocks)
i don't know what diffs are available for your axles, or even if there is a difference in ratios between different engines, be it engine size or fuel type, if you say tyres are correct then i would suspect 'wrong' ratio diffs have been fitted at some time in an effort to get better mileage.
(usual disclaimer applies... this could all be bollocks)
porkflap
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- derbyshire
mmm never thourght of that its something to think about though!
James
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If the GPS is slow to read and more acurate, and the tyres are not brand new then there will be a difference of nearley 10mph at say 70mph.
Is the speed difference constantly 10mph under at even 20mph?
Is the speed difference constantly 10mph under at even 20mph?
porkflap
New Member
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that's what's odd its out by excactly 10mph at any speed so when it says 30mph its 20mph right up to saying 80mph but traveling at 70mph
James
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- Reading, Berkshire
Take the pannel to bits and reemark on with a pen the acorrect speed. It is only a needle wafting infront of a piece of cardboard with numbers on it anyway!
