Hellcat said:

Part of the current diesel MOT is a single rev to the limiter.

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For a fast pass yes - more are needed when taking an average smoke reading on an mot.

Citizen Smith said:

For a fast pass yes - more are needed when taking an average smoke reading on an mot.

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They don't do that now, or shouldn't need to. Single rev to limiter.

Me and one of my mates both have a GP 120 sporting anf both of them have recently had a new clutch and the gear box re-sealed under warrenty and never had no problems with the dealer claiming over revs they also put the clutch down to weak clutch springs so for all sporting owners check behind your front passanger wheel for gearbox oil!! (both only 18k on the clock)

Citizen Smith said:

As said by HC diesel smoke test would need to go full throttle so would that cause over rev log entry ?

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Passed 3 MoTs with my JTD and as already said the counter is still at zero.

I think the abuse needs to be sustained - such as 1.8 secs as quoted by Oldschool :chin: - for the counter to trigger.

Argonought said:

As already pointed out by ducasi that simply means the engine has been over-revved so many times that the counter has lost track. It would translate to extreme abuse

What would be significant is if they never reject (or at least warn about) engines in the range of say 50-100 or 100-200 times etc. This would be statistically significant and might indicate a software glitch exists :chin:

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The indicator losing track and counting 255 times on most cases would indicate to me that the car has not been over-revved but the is some sort of software bug in the ecu software.

These things happen.... The problem is finding it and getting out a fix... something which is hard if FIAT don't actively look at it.

Hellcat said:

They don't do that now, or shouldn't need to. Single rev to limiter.

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If on the 1st rev the reading is 1.50 or under then a fast pass is given, over 1.5 then an average is taken over up to six revs with the limit of 3.0 for turbo'd engines and 2.5 for n/a engines

Hellcat said:

er...



It's not hard to hit it, it's not hard to go over it. I've dropped into 3rd once instead of 5th coming down from 6th and almost over-reved but as the clutch started to bite I noticed quick enough and engaged the cluch back in fast enough to prevent an over-rev.

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I should of been clearer, what I mean is a diesel generally revs up slower than a petrol, you've got much less of a chance therefore of hitting the limter.

1. How can I over rev when my tachometer does not have a red zone?

2. Do diesel and petrol engines share the same gearboxes, at least in some cases? If so, how could they claim that running a diesel momentarily at 5200 RPM is over revving when a petrol engine connected to the same box may be turning 7200 RPM for a moment? Don't say it's because diesels have much more torque. By itself, that's true. The difference is all that torque is developed by 2000 RPM and not at 5000 RPM as some petrol engines do.

HgtBill said:

I should of been clearer, what I mean is a diesel generally revs up slower than a petrol, you've got much less of a chance therefore of hitting the limter.

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That might be true of the classic view of a diesel but if you'd ever driven a JTD then you wouldn't make that comment.

I can assure you in the lower gears, when remapped, the tacho needle is like a blur :devil:

Hellcat said:

Part of the current diesel MOT is a single rev to the limiter.

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Luckily, with the first MOT not being due until car is three years old the warranty is finished anyway.

Argonought said:

That might be true of the classic view of a diesel but if you'd ever driven a JTD then you wouldn't make that comment.

I can assure you in the lower gears, when remapped, the tacho needle is like a blur :devil:

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I second THAT!

have there been any instances of a diesel over-rev warranty turned down?

Just interested as to WTF you putting too many revs on engine has to do with the gearbag going pop.

StevenRB45 said:

Just interested as to WTF you putting too many revs on engine has to do with the gearbag going pop.

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I think the view is that it's not even possible to register an 'over rev' count except in the case of severe engine braking :chin:

..thus the gearbox is likely to suffer as much as the engine.

Oldschool said:

This was the idea when I started the thread.

In the particular case I have started digging a bit deeper. It is claimed that the car had 3 over revs of 1800 milliseconds at 6500rpm on a Diesel. Also it emerged (much later although they knew it) that the rpm sensor had a fault. Still warranty warranty is refused.

Next step is hitting hard. But would help to get more cases together and it will go to the relevant authorities.

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Must admit to being a little puzzled by your comment mentioning 6500rpm on a diesel. Most, if not all the "small" diesels I've ever driven have produced maximum power at just before 4000 revs. 6500 must represent an over-rev of about 60%. Is any standard diesel capable of those sort of speeds?

ducasi said:

The number was 255, and it's not that suspicious as that's the highest number a computer can store in an 8-bit counter. Once the count reaches 255 it must stop counting.

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It would be interesting to check out a brand new car and see what is logged and if it red 255 that would cancel fiats claim and put it back as a design issue!?! [retired ex warranty engineer]

The Beard said:

Must admit to being a little puzzled by your comment mentioning 6500rpm on a diesel. Most, if not all the "small" diesels I've ever driven have produced maximum power at just before 4000 revs. 6500 must represent an over-rev of about 60%. Is any standard diesel capable of those sort of speeds?

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next time you drive one change down to second gear at 70mph an see what revs read, not in your own car though

Oldschool said:

After speaking to some of the lads at Stanford Hall it became clear that what a number of people suspected actually seems to be happening.

Quite a few claims are refused because supposedly the engine has been over-revved so often.

As this is a very serious topic: Please refrain from spamming.

If a pattern can be established steps will be taken to bring this to the public attention. This can only be done when we have all the facts and not just speculation and hear-say.

Currently I help Red Dot to overturn the claim refusal on grounds I would call at least dodgy if not fraudulent.

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Well use this link for those who are not happy with the Fiat response and something will get done if we ALL put posts [that apply to us] to :http://www.bbc.co.uk/watchdog/gotastory/

Perhaps there is a difference of opinion as to what constitutes "over-revving"?

I spend most of my time on an economy drive, 30 mph around town (it's all a 30 zone), gentle accelleration & hardly any braking, just decelleration. I often get a tortoise & hare scenario through the many stop/starts around town where I can pootle through the lot whilst barely moving my right foot whilst matey boy in the chavmobile pulls 15g away from each set of lights then has to chuck out the anchors to stop at the next set 100 yards away (and we tend to reach the last set at the same time).
It could be said that matey boy is over-revving & damaging his powertrain by going from idle (600-800rpm?) to flat out (4-6000rpm?) in an instant.
This surge in power (ha, I know - chavmobile / surge of power???) can't be doing the engine/gearbox any good can it? (I'm thinking about all the shearing forces acting on the components as they are forced to suddenly spin extremely fast).

So whilst much of the discussion here is about hitting the redzone or maxing out the rev counter, Fiat's thinking may be that people are treating their domestic vehicles like a formula 1 racing car - and how long do their engines last without a stripdown & rebuild?

oldoiler said:

It would be interesting to check out a brand new car and see what is logged and if it red 255 that would cancel fiats claim and put it back as a design issue!?! [retired ex warranty engineer]

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When Fiat first made us aware of the over-rev counter we checked a variety of cars on PDI out of curiousity, and they all read 0 over-revs, 0 msecs.

It's possible to accidently hit the limiter when carrying out a phonic wheel learn, but it would only be a fraction of a second and the speed reached would be the fuel cut-off point (limiter), and not beyond it. Unless the Dealer has done 85 phonic wheel learns on PDI, it's not going to go out the door with 255 over-revs.