307 speeding up on it own!!! Help!

[garethned]

Hi Folks

I have a 307 HDI 2005 90hp which for some reason does not like 5th gear when driving at 30mph. The car will speed up on its own, without me having my foot on the pedal. It speeds up to around 35mph then decreases back as normal??? It is lumpy round 30mph in 5th, but ok at 40mph?

What could this be? I've had it serviced, oil, filters etc and recent camblet change.

There is a anti pollution fault displayed on the dash, but this is the egr solenoid valve which I have replaced - but the connector to the valve is faulty i.e does not have a good connection...could this be the reason for the car speeding up? And does anyome know where I could buy this connector??

Thanks

Gareth

[JazzJPH]

Why are you driving this car at 30mph in 5th?!?

I have gone to 4th maximum at 30mph.

In the petrol megane hire car I had, I went to 5th. If it feels nasty then drop a gear.

[john_h]

apart from the warning this sounds normal especially as its a diesel.

you will also get the same when you are in 1st and slow to around 5mph...the car will tug under its own power...petrols just stall out.

[jmkent]

I wouldn't go driving in 5th gear at 30mph, the revs must be non existent! The car can't have any pull at that level, and I wouldn't be surprised if you're putting a lot of undue strain on the engine, gearbox and clutch too.

[john_h]

jmkent - yeah on mine revs sit just below 1k revs...just pulls along by itself to "keep alive" so to speak. very rare that i do that...last time was in the snow - higher gears, lower revs sorta thing

the 1st gear one is class for when your in crawling traffic.

can even pull away from standing still without using the accelerator...i just go mega slow with the clutch.

[DGH308]

I have something similar that happens on my 308 diesel.

At about 30mph in 4th gear, if I take my foot of the accelerator the car stays at the same speed.....not all the time but occasionally.

[john_h]

it must be the nature of diesels.

[clanless]

It's the cars computer revving the engine to prevent a stall.

My Mondeo had the same 'feature'.

[jmkent]

I think all diesels will do it, and I allow it to when crawling in traffic, 1st or maybe 2nd gear, but I wouldn't try driving in 5th at 30mph though as that isn't just ticking over crawling along, but actually driving

[JazzJPH]

Why not try this:

start car and leave in neutral. take mental note of the RPM at idle speed.

Then travel at 30mph and put it in 5th. Take foot off accelerator and check speed and the RPM. If, at 35mph, your RPM is the same as it was at idle speed, then your answer is this:

Don't put it in 5th at 30mph because that's jus' silly!