Technical Panda 4x4 shuddering when ELD engaged

[Jamie KC]

Hi,

I'm looking to buy a Panda 4x4 (2012+ model), or a Cross if my budget can stretch to it.

I've been to view a couple this week and found something unusual (or maybe not) when test driving them.

Car drives fine, but when I press the ELD button to engage it (green light on,) and manoeuvre at low speed with the wheels turned the car shudders and doesn't roll as easily. Happens in both forward and reverse, but only with a reasonable amount of lock, not in a straight line. You may often do this if negotiating an obstacle off-road on a slippery surface, so seems strange it would feel like this.

Have had a search about but haven't come up with an answer yet, so hopefully someone here can reassure me if this is normal behaviour or not, and whether I should avoid cars that do this!

Both cars I drove did this, one at 49k, and one at 70k. Is it just a 4x4 model thing, or would the Cross act the same way?

 

[Herts Hillhopper]

This is correct! You must not engage the ELD on tarmac (unless well covered in snow etc), and must avoid full lock manoeuvres when it's turned on. If the surface is slippery the wheels can 'slip' a bit to prevent the effect you are describing - basically 'winding up' the propshaft and releasing the wind-up through shredding bits off the tyres (all as mentioned in the owners manual). When you press it, you force 4 wheel drive, but as there is no central differential to allow for each wheel wanting to rotate at a different speed at or near full lock, you instead run the risk of damaging the 4WD system, especially its (fairly) fragile centre propshaft bearing mount

The car will engage 4x4 by itself without the ELD button being pressed - it is always sitting waiting in 'auto 4x4' mode when the light is off and adds in the rear drive at the slightest hint of a front wheel slipping (you cannot turn off this 'auto' mode).

Despite what it says on the button, it does not turn on any diff locks. It does force 4x4, and it allows the ABS system to apply the brake to a spinning wheel (simulating a diff lock effect), but only if the ABS system chooses to. This simulated diff lock will not happen if the setting is off. Even in seriously muddy or snowy conditions I have never yet needed to press the ELD button... only really needed if a wheel is up in the air, off the ground.

By the way, on the Cross, it too works exactly the same way, but more correctly shows 'auto', or 'forced 4x4' (off road mode) on its rotary control. It has a third setting (not available on the non-Cross 4x4) of Hill Descent too that allows the ABS to apply or release brakes to each wheel separately to try and minimise sliding on downward slippery stuff. This is more of a necessity with the TwinAir 4x4, the diesel has much more engine braking and can generally cope on downward slopes, 'all feet off' the pedals (as you would in an old Landrover)

Apart from the added Hill Descent Control, the Cross mechanical stuff, 4x4 system and suspension is identical to the regular 4x4. It has about 6mm more ground clearance because it has slightly taller tyres, and has auto aircon and a couple of extra airbags. Otherwise, the differences are entirely down to different plastic bits on the bodywork.

Oh, and have a look at this thread if you're looking at 4x4s: https://www.fiatforum.com/threads/another-rusty-panda-4x4-sump-guard.502369/ and here https://www.fiatforum.com/threads/rusty-sump-guard.486312/ . The sump guard should come off at every service (you need to to reach the oil drain), but the state some have got into suggests they may not have been.

 

[Jamie KC]

Thanks for the response, very informative and handy. So don't engage at anything approaching full lock even if off-road on a slippery surface?

Sounds like it is very rarely needed though. Perhaps just if trying to get out of the mud/snow and both front wheels revolving at the same speed so 4x4 not automatically triggered.

I went to see a Cross, the sump guard was almost non-existent. It had the front and rear mounting points still bolted up, and some scraps of metal held together with cable ties, but most of it was gone. I was gobsmacked at how bad it was, espesh for a 60k car!

On the subject of Cross vs 4x4, is there also a difference in wading ability. The Cross spec suggests it is 73cm, but have seen suggestion that with a normal 4x4 you wouldn't want to go to more than 30cm.

 

[Herts Hillhopper]

Wading abiliy is no where near 730mm!! The air intake under the bonnet might be at that height but plenty of other, critical, electrical stuff much lower. And the various breathers on gearbox, diffs, etc too. Even a ten year old Defender can’t go that deep without having a wading kit fitted (which plugs those diff vents for starters).
My cars alternator (which is one of those things mounted lower down) whines constantly after fording a deep flood earlier in the year. To remove it entails removing the front right driveshaft and all that goes with that, so for now I put up with it.

Safe, briefly, limit is the height of the door sills, or the wheel centres (generally this is true of all ‘off roaders’). The Panda 4x4 was conceived for driving on alpine roads covered in snow.

On mud etc, you can use full lock with 4x4 as the slippy surface releases the wind-up easily. Again, true with a Defender too, where the centre diff must not be locked on tarmac and full steering lock should be avoided when it is locked unless the ground is slippery.

In theory, 4x4 will engage if either or both front wheels are turning and one or both rears are not - it uses the ABS wheel speed sensors to activate 4x4, unlike the older model which relied on a viscous coupling

 

[Jamie KC]

Thanks again for the info

 

[Herts Hillhopper]

A bloke in a van once saw me stopped where a deep flood had blocked the road under a railway bridge. He shouted out ‘it’s ok mate, you’ve got a 4x4’, as if somehow that made a difference. 4x4s (of any make) are no more waterproof than their two wheel drive equivalents: wheel bearings, gearboxes, timing belt/chain cases, alternators… all these things don’t cope with being submerged (except, if you’re lucky, briefly). Then there’s the whole airbag control system, usually mounted under the carpet in the centre of a car. The slightest hint of water in there will write a car off! That’s why after a wet winter, Ebay etc is full of ‘written off’ cars that look undamaged - the cost of replacing the SRS system is prohibitively high.

The van drove into the flood and stopped very abruptly as water got drawn into his diesel engine. I smiled.