2020 Fiesta 1.0 ecoboost mhev. On the rare occasion that I block change from 3rd to 6th at between 3500-40000 revs there is a grinding noice as if there is a synchromesh problem, all other gears are fine. Just wondering if this is an isolated issue, and wether it needs attention 

I'd get it checked if you are still in warranty

1 hour ago, DaveT70 said:

I'd get it checked if you are still in warranty

Cheers Dave. I’ll do that. It’s just that this is the first car I’ve had with 6 gears and wasn’t sure if it was a common problem for a block change from 3-6 to grind the synchromesh slightly when engaging. 

That's a big ratio change for the syncromesh to cope, particularly if you revved high in third. Perhaps the clutch is dragging slightly but getting it dealer checked if it is still under warranty is the best idea.

I don't think this is a fault.  Just the alignment of the 'box means it's an awkward change from 3rd to 6th.  Skipping gears on the way down is fine but I wouldn't skip more than one on the way up myself.

I have no idea why you would want to do that - never heard of anyone doing that before. So I'd just not do it and then there won't be any noise. Happy days.

1 hour ago, alanfp said:

I have no idea why you would want to do that - never heard of anyone doing that before. So I'd just not do it and then there won't be any noise. Happy days.

Block changes are a far more efficient way of driving, with their most common use being when speed is being reduced. An advanced assessment is made for the possible gear required to maintain comfortable speed, reducing unnecessary gear changes and avoiding the car coming  to a complete stop.

Block changes up, so long as the speed and revs match comfortably is also the most efficient way resulting in less wear on components, much the same reason why you wouldn’t use first gear in certain circumstances… hope this clarifies a bit and is all part of advanced driving techniques 

I think that Ford will tell you that there is nothing wrong with the car.

Block changing seems to be a fad that is promoted by driving instructors, these are the same people who wrongly tell their pupils to keep their Handbrake buttons pressed in when applying even though all car manufacturers tell you not to. 

11 minutes ago, Tizer said:

I think that Ford will tell you that there is nothing wrong with the car.

Block changing seems to be a fad that is promoted by driving instructors, these are the same people who wrongly tell their pupils to keep their Handbrake buttons pressed in when applying even though all car manufacturers tell you not to. 

More than likely they will say the car is fine. But your point on block changes is incorrect. These are Advanced Driving Techniques supported by the IAM who’s observers train large numbers ADI’s, and where they some probably picked this up from. This technique is also supported by the IMI and Police Training. Your point on handbrakes is to a degree correct but it’s more the rasping noise that isn’t pleasant and for that reason is discouraged. 

1 hour ago, Rottiethedog said:

More than likely they will say the car is fine. But your point on block changes is incorrect. These are Advanced Driving Techniques supported by the IAM who’s observers train large numbers ADI’s, and where they some probably picked this up from. This technique is also supported by the IMI and Police Training. Your point on handbrakes is to a degree correct but it’s more the rasping noise that isn’t pleasant and for that reason is discouraged. 

The IAM don't design cars, nor do ADI's or the Police. As for the IMA, taking Engineering advice from an Accountant is as laughable as asking the Greens to solve the energy crisis. If cars were meant to change from third to sixth they would only have four gears.

The point about the Handbrake is 100% correct, not just correct to a degree.

If any Accountants, the IAM, ADI's or the Police think they know better than the people who design cars I would be interested to hear their thoughts.

2 hours ago, Tizer said:

As for the IMA, taking Engineering advice from an Accountant is as laughable as asking the Greens to solve the energy crisis. 

Are we confusing the Institute of the Motor Industry (IMI) with the Institute of Management Accountants here?😀

I've always block changed myself, but in very limited circumstances e.g. slowing for a roundabout while braking to a very low speed, then selecting an appropriate gear to be ready to move off or stop. Likewise occasionally on upshifts at higher speeds, but never 3 gears at a time and only under easy load, certainly not at the revs mentioned.

Yes, I did get advice on this from my first driving instructor, the IAM and various ex-police ADI's but like all things in life, you absorb advice but don't have to follow all of it slavishly. 

I recall having a "heated" debate years back with various IAM instructors on their then doctrine that you shouldn't brake and change gear simultaneously on the grounds that the brakes might be out of balance and the car may pull to one side, and only having one hand on the wheel may not be enough to counteract this. I discovered that this emanated from the pre-war police roadcraft manual when most cars still had cable operated footbrakes!

34 minutes ago, Eric Bloodaxe said:

Are we confusing the Institute of the Motor Industry (IMI) with the Institute of Management Accountants here?😀

Yes I did misread that🤭.

I mostly change from sixth to fourth in a seamless way when leaving a Motorway when approaching the inevitable bend and slip road because fourth is normally the correct Gear to be in to have control of the car in any unexpected situation that may arise and for no other reason, but have never felt the need to the same at any time when moving up the Gears.

I do agree that some of the advice that is banded about may have been correct at one time but not now. The one that I roll my eyes at is the one that says you should start off in second gear on a slippery road and drive in the highest gear possible.

I learned to drive in a town that got heaps of snow every winter and often witnessed people driving at 15mph in fourth, they then come to an uphill section where they would run out of steam half way up and change down to second, which is the correct gear, but because they are only crawling at that point they would lose it completely.

They should have moved into second before the hill and with a steady and not too wide open Throttle and the Engine Torque would have taken them up easily as long as they did not try to open the Throttle any more.

As for starting of in second, my first cars were all RWD and without any form of Traction Control and to this day I have never had to start of in second.

 

9 hours ago, Rottiethedog said:

Block changes up, so long as the speed and revs match comfortably is also the most efficient way

.. but in this case, they clearly don't, hence the initial post.

It's unlikely (by which I mean impossible 😉) that the engine is at high efficiency both at 4000 rpm in 3rd and also 2000rpm in 6th.  If block changes up was most efficient, cars would only have 3 gears.

 

10 hours ago, alanfp said:

.. but in this case, they clearly don't, hence the initial post.

It's unlikely (by which I mean impossible 😉) that the engine is at high efficiency both at 4000 rpm in 3rd and also 2000rpm in 6th.  If block changes up was most efficient, cars would only have 3 gears.

 

https://www.iam-bristol.org.uk/index.php/articles/associate-s-guide/22-gears-block-changing

1 hour ago, Rottiethedog said:

https://www.iam-bristol.org.uk/index.php/articles/associate-s-guide/22-gears-block-changing

Yeah, that's pretty much in line with the guidance I've had over the years, but as they say at the very end:

 "It is not a prescriptive science.  You have to make the right assessment in each situation and plan which response is going to be the most appropriate in each."

1 hour ago, Eric Bloodaxe said:

Yeah, that's pretty much in line with the guidance I've had over the years, but as they say at the very end:

 "It is not a prescriptive science.  You have to make the right assessment in each situation and plan which response is going to be the most appropriate in each."

This thread has deviated from the original question. For clarity, the issue arises mainly  if I’m joining a motorway with a declining slip road to the motorway that is also declining. These journeys are usually at 04:00 with very little traffic. So on the slip road in 3rd the car is already at a speed and gaining momentum and where 4th gear definitely isn’t a required change. 5th could be selected but the difference between 5th and 6th are minimal and a direct shift from 3rd straight down to 6th on the gearbox should be a far smoother, quicker and more efficient change rather than change from 3rd and then to cross over the gearbox and back up into 5th, and then change into 6th. And as your highlighted text implies, was I to be joining a motorway from a lower level this manoeuvre would be totally inappropriate.  My apologies for not stating this in the original post, but it was meant as a mechanical question rather than a question on driving skills of techniques.  

2 hours ago, Rottiethedog said:

This thread has deviated from the original question. 

Unfortunately they usually do on here, Bernard!😀

I appreciate that your original point was whether there was a mechanical issue.

It does appear though, that so far no one is able to comment definitively on your point as it seems no-one else has tried going from 3rd to 6th.

There were numerous issues with weak synchromesh on the earlier gearboxes in the previous model Mk 7.5 Fiesta Ecoboosts.

It was hoped that the 6 speed box fitted to the Mk 8, which has a higher torque capacity, would cope better, but I have already seen a few reports of issues with this box. It may be that the torque delivery of the MHEV system adds to this, but it's still early days.

Whatever, I treat my gearbox very gently as mentioned earlier in the thread.

 

 

 

10 hours ago, Rottiethedog said:

it was meant as a mechanical question rather than a question on driving skills of techniques.  

So to give you a more meaningful answer to your original post, I think the car is fine.

But if you're still concerned, take the car back to your Ford dealer and ask them if they think the car is OK.