hi,

Please can somebody shed some light on the revving problem on my 53 plate 1.9 sdi octavia - hopefully somebody has had this problem in the past (even tho i would not wish it on anyone) and has been succesfull in locating the cause.

Basically whenever i am on the motorway doing about 85mph the rev counter hits 5000 revs (red lining) - which is flashing cause for concern in my head.

I assume that this is having a very bad effect on the engine as from the noise that is makes, is being worked very hard - and also the fuel consumption - i have taken it to many garages who cant locate the problem.

The cluth would be the obvious problem but all of the power there - so i can rule that out - this has also been confirmed by a garage.

Can anybody help me with this problem as i dont want to carry on driving it while the problem still remains as the engine is being worked to its limit, when i am not even going that fast (85mph). - Much Appreciated

Surely, and if I'm reading this correctly, if you are only doing 85mph on the redline in 5th gear then something on the driveline is slipping - the clutch.

hi,

Thanks for your reply - the cluth system has been checked by a specialist company - and it come back with no problems.

I don't follow- are you saying that in gear, with the clutch pedal not pressed, the engine revs shoot up to 5K when you press the accelerator, with the speedo showing 85?

If so, your clutch must be slipping, surely? There is *no other* way for the revs to climb that high in top gear at 85mph, unless you press the clutch pedal.

[edit]

VRStu- beat me to it.

Does the speed up hill slow but the engine still revs?

Also does does it just happen in fifth or most top end gears?

Yes sounds like the clutch???

Go for a drive in the car and @ 1000revs in 4th floor it if the revs jump from 3500 - 5000 then it's defo the clutch

hi,

Thanks for your reply - the cluth system has been checked by a specialist company - and it come back with no problems.

Well, if I understand your question properly, they are wrong, and to be honest, to check the clutch properly, you need to drop the gearbox. Like another poster has said, get in in 4th/5th at 1000rpm rolling, then floor it. If the revs shoot up, the clutch is slipping.

If it's not the clutch plate then it must be the mechanism.

The transmission is geared, phyisically connected. I don't see as it can be anything else.

no

Basically as i climb through the gears everything is fine i.e power and rev - however once i go into 5th gear and climb to around 85mph the revs are at 5000 - the rev counter never shoots up - it climbs normally as you increase speed - but something is wrong if i cant go more than 85 - 90mph

Has someone been messing with the gearbox fifth gear?

no

Basically as i climb through the gears everything is fine i.e power and rev - however once i go into 5th gear and climb to around 85mph the revs are at 5000 - the rev counter never shoots up - it climbs normally as you increase speed - but something is wrong if i cant go more than 85 - 90mph

Right, but lets say you've got up to 85mph, and you let off the throttle, what speed is shown on the rev counter? I'm guessing about 3-4000 rpm?

Then if you put your foot down, the revs climb but the car doesn't go any faster?

Clutch.

Unless you mean that the car has *always* revved at 5k at 85. That's redlining a diesel. In that case, sorry, you need a more powerful car. I've never driven a SDI, so i don't know what is normal.

One thing though... how fast will an SDI go anyway?

there was a problem with the gearbox when i first bought the car - the 1st and second gear didnt go in properly - so a re-conditioned gearbox was fitted.

And was it ok after the box was fitted?

or was that when your troubles started?

there was a problem with the gearbox when i first bought the car - the 1st and second gear didnt go in properly - so a re-conditioned gearbox was fitted.

Could you perhaps have the wrong gearbox with too low a ratio set fitted then?

It this problem new, or has it existed since the gearbox was fitted?

One thing though... how fast will an SDI go anyway?

101 Mph

And was it ok after the box was fitted?

or was that when your troubles started?

hi,

Silly reply back but to be honest the car was given to my mum to drive - and i dont honestly feel that she would of noticed the problem - so it may be worthwhile getting the gearbox checked out?

101 Mph

Any idea of the MPH/1000rpm, so we can tell what the revs *should* be at 85 mph?

If it's not the clutch which does seem likely to me, then it suggests a problem with the gearbox or selector mechanism. It could be possible that it is staying in a lower gear (3rd maybe) even though the 5th gear position is selected. What are the road speeds at 2000 revs in all the forward gears.

What is the history with the car, has it work done on the gearbox before, is this a problem that has ocurred recently or has the car always done this?

After refreshing the page other replies along these lines have appeared, have the change cables been set up properly?

Any idea of the MPH/1000rpm, so we can tell what the revs *should* be at 85 mph?

around 15mph

Could it possibly be that someone has put the wrong ratio from say a petrol gearbox in as the fifth gear ( this would make it behave like this)...just a thought

I know steve changed his box for a diesel box so he could get more top end speed due to different ratios.

hi,

Silly reply back but to be honest the car was given to my mum to drive - and i dont honestly feel that she would of noticed the problem - so it may be worthwhile getting the gearbox checked out?

Check the gearbox code stamped on the casing.

I suspect you might have a gearbox from a different model fitted, so the gearing is too low.

Check the gearbox code stamped on the casing.

I suspect you might have a gearbox from a different model fitted, so the gearing is too low.

right - thanks for ever1s input i will definately taking it to a different company who specialise in gearboxes and cluthes - not sure if any1 no's A1 cluthes in the black country (west mids)

around 15mph

I was after the book figure for an SDI. That sounds *very* low geared for a 1.9 diesel. No wonder you are hitting the redline.

right - thanks for ever1s input i will definately taking it to a different company who specialise in gearboxes and cluthes - not sure if any1 no's A1 cluthes in the black country (west mids)

Don't know them, no. Whereabouts in the West Mids are you?

Don't know them, no. Whereabouts in the West Mids are you?

west bromwich - they are based in tipton - will have to book it in for a check