Peugeot 407 Coupe 3 litre petrol - Over reving

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Wed 13 May 2015 11:45
Peugeot 407 Coupe 3 litre petrol - Over reving - mousetarget

This is quite scary and now has happened to me a few times of the last few weeks.

The car will suddenly rev over 6000rpm, no matter what gear I put it in, the revs do not come down, the car then continues to keep its speed at a constant pace without me touching the accelerator pedal - this lasts for about 20 seconds and then the revs return to normal and I have full control of the accelerator pedal again. Afterwards there is a strong burning smell from the engine.

Anyone have any ideas?

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Wed 13 May 2015 11:50
Peugeot 407 Coupe 3 litre petrol - Over reving - RobJP

Get it into a garage !

Yes, seriously.

A car that revs uncontrollably is an accident waiting to happen. Continuing to drive it is grossly negligent, and shows a total lack of any regard for other road users, pedestrians, etc.

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Wed 13 May 2015 12:17
Peugeot 407 Coupe 3 litre petrol - Over reving - mousetarget

Its been in a garage 3 times already and with no answers.

Although it revs out of control the car does not speed up but maintains a steady speed and I can still control it with the brakes and steering.

I don't drive it anymore - except to the garage! - which is why I have come on here to see if anyone has any ideas?

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Wed 13 May 2015 12:20
Peugeot 407 Coupe 3 litre petrol - Over reving - skidpan

The car will suddenly rev over 6000rpm, no matter what gear I put it in, the revs do not come down, the car then continues to keep its speed at a constant pace without me touching the accelerator pedal

Hopefully you are joking.

6000 rpm in 3rd would probably equate to about 90 mph, 4th and 5th would be way above this. Are you suggesting that you are driving at these speeds.

People have been killed and have killed other driving cars with such issues as you have.

Take it off the road and get it sorted.

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Wed 13 May 2015 12:21
Peugeot 407 Coupe 3 litre petrol - Over reving - mousetarget

See my above reply - the car isn't going fast despite the reving and I only use it to take it to the garage - does anyone have any ideas what it could be?

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Wed 13 May 2015 12:26
Peugeot 407 Coupe 3 litre petrol - Over reving - skidpan

The information you provided in your first post was incorrect. It clearly does not "car will suddenly rev over 6000rpm, no matter what gear I put it in, the revs do not come down".

Tell us the real facts.

Edited by skidpan on 13/05/2015 at 12:26

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Wed 13 May 2015 12:34
Peugeot 407 Coupe 3 litre petrol - Over reving - mousetarget
This is correct - I can be travelling along at any speed, and then suddenly the car will rev over 6,000rpm and keep doing this for a good 20 seconds, almost as if it has slipped out of gear, but it hasn't and I've had the gear box checked and oil changed as well.

The accelerator pedal is depressed slightly on its own and the car maintains the speed it is going on its own for those 20 seconds and then the revs come down to normal.
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Wed 13 May 2015 13:00
Peugeot 407 Coupe 3 litre petrol - Over reving - mjm

The symptoms suggest that the car has an automatic gearbox or a malfunctioning revcounter. We don’t know the year of the car but I think that both the earlier and the later auto gearboxes have torque converters and some degree of manual gear selection. If this is so then a transmission fault is probably the culprit. I would be using an auto transmission specialist and not a dealer.

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Wed 13 May 2015 13:09
Peugeot 407 Coupe 3 litre petrol - Over reving - mousetarget

Many thanks.

Sorry, should have said the gearbox is manual. Its not a faulty rev counter as the engine is actually reving up over the 6000 rpm and then omitting a burning smell afterwards

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Wed 13 May 2015 13:22
Peugeot 407 Coupe 3 litre petrol - Over reving - skidpan

If the car is a manual the only way the revs could rise to over 6000 rpm with no increase in road speed would be if the clutch was slipping. That would account for the burning smell.

But don't worry, if it continues the engine will soon end up as scrap.

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Thu 14 May 2015 21:51
Peugeot 407 Coupe 3 litre petrol - Over reving - hardway

Is this car fitted with cruise control?

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Fri 15 May 2015 14:08
Peugeot 407 Coupe 3 litre petrol - Over reving - madf

May I suggest we get miles, service history, who services it before commenting further . And the age...

And whether the car is standard . Or modified in any way.

So far the story is patchy and incomplete. We need more data.

Edited by madf on 15/05/2015 at 14:09

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Mon 18 May 2015 14:15
Peugeot 407 Coupe 3 litre petrol - Over reving - mjm

It’s a 3-litre petrol manual. At certain loads the clutch is slipping and the engine revs are rising with no increase in road speed, standard worn out clutch behaviour. The revs quoted in the original post indicate that the rev limiter is stopping the engine self-destructing. The “strong burning smell” is an indication of further destruction of the clutch friction plate. The heat generated will have also started to affect the cover plate. Assuming that Mousetarget is not riding the clutch pedal then the car needs a new clutch assembly, complete.

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