ScaniaPBman

How to run the front wheels when the rears are on the ground.

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Well the title needs an explanation.

As a start to my investigation into front end vibration I have my car up on axle stands at the front only.

The rears are on the ground and firmly chocked.

I propose to get Mrs ScaniaPBman sitting in the car and accelerating the front wheels while I observe from the outside.

On a trial run just now there are a lot of strange noises from the front. It sounds as if the anti lock brakes and/or traction control is being activated. I can understand why this might be the case since the front wheels are rotating when the rears are stationary.

I thought about pulling a few appropriate fuses but on second thoughts considered seeking advice from the experts here on the best way to proceed.

The car is a 2010 Mk 2.5 1.6 petrol 100BHP Zetec auto. Bog standard with no mods.

Your guidance would be appreciated,

ScaniaPBman.

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The differential sends all of the power to the easiest wheel, this is usually nearside when off the ground due to the shorter driveshaft unless you've got  a slight brake bind on that  side or the car isn't level.

Even if you can get both turning there will still be a speed discrepancy between them which will set off the traction control as you've found out.  Pulling the ABS fuses should stop that problem.  I really wouldn't recommend accelerating on axle stands though, far too much potential for carnage if the stands slip.

 

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There is no ESP that I know off on my car but thanks for mentioning it WWW.

I followed your advice, Tom. They clearly don't want to make fiddling with the ABS fuses easy, I found them hidden behind a second cover. Removing the small 10A dagger fuse did the job, just as well since I am convinced the bigger box shaped fuses are welded in.

It didn't take long to pin the vibration down to the near side wheel, as you said you can get a speed discrepancy side to side. With the right hand side wheel stopped it was clearly the left one causing the car to shake.

Next stop is to have the wheel balance checked, it's only recently had a new tyre fitted there. No sign of any impact to cause buckling etc.

By the way I feel quite safe with the setup as described, I have spent a fair amount of time working beside cars on rolling roads with engines powered up, not just fast idling as I was doing.

You are correct, if you haven't the experience or the confidence don't do it.

ScaniaPBman.

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2 hours ago, ScaniaPBman said:

There is no ESP that I know off on my car but thanks for mentioning it WWW.

Not to second guess you but are you totally sure? I was sold on the facelift based on the fact they all had it as standard?

Parkers has a write up for the FL:

"Cars from 2008 are offered in a re-structured range featuring Studio, Style, Zetec and Titanium trims - plus all cars get ESP as standard."

The only difference between mine and yours is the Auto really, but I'd have thought if anything itd have more driving aids being auto?

Either way I've definitely learned something if yours doesnt!

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I will be pleased to be wrong.

Tell me where I should look on my car to confirm ESP is fitted.

There is nothing obvious to me.

ScaniaPBman.

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No ESP button, where should it be?

Have I missed it in my 2 1/2 years of ownership?

Mind you Mrs ScaniaPBman will confirm I am hopeless when it comes to finding something.

ScaniaPBman.

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For me theres no button either, but on the dash stalk thingy, go to menu and press set, then down once should be ESP, set again and you should be able to choose off, make sure you go back to the menu again and itll turn off ESP and a light will come on for all the time it's off. (It goes back to normal if you turn off ignition anyway)

I'll do a video of mine in the morning if you need it?

 

Edit: YT ftw..

 

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Posted (edited)

Well Mrs ScaniaPBman was right yet again.

I have just been out and selected the main menu to find that there is an ESP option on my car.

Thanks everyone, I must say I have not come across it whilst driving but there again my boy racer days are long gone.

Good work,

ScaniaPBman.

PS. On the coaches that I drive, all the recent ones have ESP and it is easy to trigger it. When taking a corner sharply with no passengers on, first it cuts the engine power then puts the brakes on. ESP comes in really early and I recon it is set to be safe with the reduced grip on a wet road.

I never get anywhere near the trigger level when carrying passengers, they would be complaining loudly if I cornered like that!

Edited by ScaniaPBman
PS added.

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Not a worry - I only know about turning mine off as when I first got the car the front tyres were that poor (new, just.. Terrible.)  it'd slip when pulling out of junctions or roundabouts; I found my car cutting power at the point I needed it most, so for a month I thought it was an issue with ESP.. I found how to turn it off and realized then how bad they actually were..

Still nice on occasion to know where it is for some of the more.. Spirited(?) Roads I occasionally drive on, the focus handles so well for such a hefty lump!

Happy to help and glad you found it - Does it in fact help you with allowing them to spin?

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I don't think the ESP can be fully turned off in the dash menu on the Mk2.5.  If you push it hard enough it'll still kick in, removing the ABS fuse ensures it can't kick in at all. :smile: 

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1 hour ago, ScaniaPBman said:

PS. On the coaches that I drive, all the recent ones have ESP and it is easy to trigger it. When taking a corner sharply with no passengers on, first it cuts the engine power then puts the brakes on. ESP comes in really early and I recon it is set to be safe with the reduced grip on a wet road.

I never get anywhere near the trigger level when carrying passengers, they would be complaining loudly if I cornered like that!

I always assumed you drove trucks from your username...  Didn't know Scania made coaches so I've learnt something there! :biggrin: 

I think the lack of weight with an empty coach will be a huge factor there, the less weight there is over the wheel, the easier it is to lose traction.  I'd guess empty coaches are probably quite tail-happy in the wet with the weight of the engine behind the rear axle as well?

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1 hour ago, TomsFocus said:

I always assumed you drove trucks from your username...  Didn't know Scania made coaches so I've learnt something there! :biggrin:

A while back a ScaniaPB was my daily drive for National Express. Hence the name stuck from that time.

I now work for a different coach operator doing entirely private hire work in new or very recent coaches through the UK and Europe. In a previous work life I spent many years in the motor industry till I retired. My current driving job is a lot less stressful than my pre retirement one, who would have thought that.

Try a search with your favourite search engine for images of a ScaniaPB or Wikipedia for Scania AB

Thanks everyone for your help.

ScaniaPBman

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