Hello all,

I'm a newbee so bare with me if I have posted in the wrong section.

I've recently purchased a 58 plate 1.6 16v Zetec S.

I don't think the car would do much more than 80mph (Not without the engine screaming)

The clutch seems fine it pulls as it should.

I do have a whistle type sound when I accelerate which could be a transmission issue.

But I'm struggling to understand how a faulty bearing or even a gearbox (manual) would affect the final drive ratio.

I looked up my final drive ratio - and it doesn't stack up with the engine speed to vehicle speed.

My old fiesta 1.25 was much better.

I'm contemplating in changing the gearbox - But I need some advise if anyone has experienced this problem before.

Hope that makes sense 

much appreciated 

I've changed the Gearbox and put a brand new clutch kit on.

Still 4000RPM @ 70MPH.    

I'm running out of ideas now - would a (Crappy Stupid Remap cause this problem)?

 

Any help would be much appreciated 

 

Regards

No.  The only thing that can change RPM to speed relation is the gearbox/diff. 

Sure your RPM is reading right? And is the replacement 'box off the right car?

 

Edit - Is this a standard 1.6 or a Ti VCT one?  If it's the latter that RPM is probably normal?

Hi there,

Its the correct box - Fiesta 1.6 16v 58 Plate.

 

I've just taken it for a drive with my (Live Feed Scanner Plugged in) The ECU is reading wrong engine speed and wrong vehicle speed.

At 70mph - the ecu thinks I'm at 105mph

At 4000 RPM - the ecu thinks its at 3700.

 

Clocks idle around 1100 - Ecu thinks its idling at 750ish

What next - Ford Dealer maybe?

Cheers

 

 

Your 4000 figure suggests a ~10% error your 70 mph figure suggests ~50%; perhaps it is something other than a straightforward error?

 

It seems that before you got the car someone fitted a wrong part, or something. Possibly someone had a gearbox failure and replaced with parts from some other model (a Fiesta van, which would have different sized wheels, for example).

Could be the transfer gears could be could be stored parameters in the ECU or Dash Electronic Module.
 

It was probably reading speed in kph rather than mph?  Have you checked with sat nav to make sure 70 on the clocks is somewhere near 70 in real speed?  Or are you doing 105mph in reality and wondering why you're overtaking everyone lol?

Sounds like the RPM is off for some reason though, but I can't see how it would be, if the ECU is getting the wrong crank sensor signal then the engine wouldn't run.  Has it got the right clocks in btw, not diesel clocks or something weird like that?

Thanks for your reply's 

I've changed the gearbox with a known 1.6 16v (low Mileage) unit - also replaced the clutch at the same time.

The 70mph is correct - that's what the clocks are showing. No people over take me at ease - (ECU is reading 105)

The car is currently at Ford being diagnosed. Mechanically I can't understand how the car can achieve this (especially with the correct gearbox)

I've spoken to a couple of people about this problem - and everyone is baffled by it - I done my apprenticeship in a main dealer as a technician (VW) I've never came across a problem like this before.

It doesn't help that I don't know much about the cars history - (Only that it's had a hard life)

luckily the car is a third vehicle only purchased it to go back and fore to work.

Cheers

Did you change the diff with the gearbox?

No Gearbox was a straight swap

So new gearbox has new diff, or did you put old diff on new box?

No have not remove the differential on either old box or replacement box.

 

I don't think it's a mechanical issue myself.  I think it's something electronic reading/displaying the RPM wrong, and just a noisy engine, they're not exactly quiet at 70, I'll bet you can push it well past the redline on the clocks.

I wrongly assumed this was a Focus to start with, now I see it's a Fiesta, surely someone else on here has an identical one that could say what the RPM should be?  I think the 1.4 petrols are about 3500rpm at 70 - which is a lot if you're used to a diesel and does seem like straining, but there's still plenty to go.

Hopefully Ford will be able to recalibrate or replace 'something' to fix the issue!

Hopefully never seen this issue before - could understand if it was an automatic and control electronically.

Odd fault probably caused by an odd kid lol.....