Technical Cross new noise from engine

[Harvie]

Had new propshaft fitted to my Cross 2015 93000 miles diesel, been in 4x4 for a month since fitting . A new noise has developed now . No shudder or loss of power but an underlying grumble. Will check propshaft bolts tomorrow. Any other suggestions. Thanks in advance

 

[AnthonyH]

Get some video tomorrow so we can have a listen.

 

[Harvie]

Thinking it to be a wheel bearing. Need listen careful, hope you hear it

 

[AnthonyH]

Sounds like the prop shaft bearings have failed. Although it's hard to tell. Who fitted the new prop shaft?

 

[Panda IIs]

Thinking it to be a wheel bearing. Need listen careful, hope you hear it

My experience of a failing wheel bearing is the sound gets worse when cornering and the failing side is loaded up (i.e. the wheel bearing on the outside of the turn).

 

[The Panda Nut]

Knock it out of gear and see if its is the same. I thought it sounded as if it was changing with engine speed. Does it do this in all gear and in neutral? Can you hear it with a window down?

 

[Harvie]

In neutral idling no noise. Noise still there if in neutral on the move. Seems to get louder with speed but negligable. Back to local garage who fitted new propshaft a few weeks ago, next week where it ll be checked properly
Thanks again.

 

[euroben]

Had new propshaft fitted to my Cross 2015 93000 miles diesel, been in 4x4 for a month since fitting . A new noise has developed now . No shudder or loss of power but an underlying grumble. Will check propshaft bolts tomorrow. Any other suggestions. Thanks in advance

What do you mean “been in 4x4 for a month since fitting” ? Have you been driving it on normal roads in 4x4 mode on the dial?

 

[Harvie]

yes. Use it in both . For where i live.

 

[euroben]

That may be your issue in that case. The off road mode on the dial should not be used on tarmac otherwise it can cause wind-up which may be causing your noise or vibration. It is only for conditions really where you have got a bit stuck.

 

[Harvie]

i took that in 4x4 mode would be same as my previous panda 4x4 's. Solution? and thanks

 

[euroben]

So your panda cross is running in permanent four wheel drive albeit a very small amount being pushed to the rear. That is in the normal driving mode on your dial. If it slips then it will send more power to the rear wheels automatically. So 99.9% of the time you never need to be in any other mode. If you were in some pretty bad mud or snow/ice you could use the off road mode on the dial and this forces the car to send 50% of the power to the back wheels and uses the ABS to slow down spinning wheels. It does the same as the ELD button on the non-cross 4x4. But if you use this mode to drive on tarmac regularly then it will wind up and cause you noise and vibration. @Herts Hillhopper knows more about this than me and may be able to add info here. I’m not sure how you ‘unwind’ it

 

[Herts Hillhopper]

So your panda cross is running in permanent four wheel drive albeit a very small amount being pushed to the rear. That is in the normal driving mode on your dial. If it slips then it will send more power to the rear wheels automatically. So 99.9% of the time you never need to be in any other mode. If you were in some pretty bad mud or snow/ice you could use the off road mode on the dial and this forces the car to send 50% of the power to the back wheels and uses the ABS to slow down spinning wheels. It does the same as the ELD button on the non-cross 4x4. But if you use this mode to drive on tarmac regularly then it will wind up and cause you noise and vibration. @Herts Hillhopper knows more about this than me and may be able to add info here. I’m not sure how you ‘unwind’ it

The solution is simple - turn off 4x4 mode. That will stop it winding up.

The dial is not '2WD' or '4WD' -- it is 'auto 4x4' or 'forced 4x4'. The latter (as others have said above) you will not (nearly ever) need to use on tarmac, and indeed must not as it will wind up the system and cause damage to the prop shaft and rear diff.

See the instructions from the handbook which are in the thread linked a bit further down this reply

The other thing selecting the 'off road mode' does is allow the diff lock to work if it needs to. For example, if one wheel comes up off the ground (such as when the diagonally opposite wheel drops into a hole or gully), that wheel will no longer have grip and so will spin freely. Because of the way a differential works, that will mean the wheel still on the ground will have no drive sent to it. The ELD system puts the brake on that spinning wheel which allows the other to drive again. This is the main (intended) purpose of the ELD button or 'off road mode' selection: to allow that diff lock function to work. The selection of 4x4 is fully automatic in the 'auto' mode and rarely (if ever) needs to be forced.

See this other thread for more info on all this... Start here and read on https://www.fiatforum.com/threads/panda-4x4-shuddering-between-10-30mph.513699/post-4788999

but yes, never use off road mode on the road.

 

[Harvie]

Thanks for all replies and help. Feel an idiot for thinking like my previous 4x4 panda.
Will it get worse, need change propshaft again?

 

[Herts Hillhopper]

Thanks for all replies and help. Feel an idiot for thinking like my previous 4x4 panda.
Will it get worse, need change propshaft again?

Don’t beat yourself up - the handbook is unhelpfully vague. A pre-2012 4x4 didn’t even let you manually engage 4x4 and was entirely auto-only engagement (with exception of the older Cross model from about 2009 on, that first introduced this more elaborate system).

 

[Bonefish Blues]

Doesn't the offroad (same as a 4x4's ELD button) automatically disengage over 30ish mph specifically to prevent damage when it's obviously not being used? IIRC the 4x4's ELD doesn't re-engage, when it's off, it's off. Does the dial-based setting operate similarly? Fiat/Steyr are not daft and would surely extend this basic protection to the Cross, since this is absolutely foreseeable?

Or am I up a tree on this?

 

[Herts Hillhopper]

Doesn't the offroad (same as a 4x4's ELD button) automatically disengage over 30ish mph specifically to prevent damage when it's obviously not being used? IIRC the 4x4's ELD doesn't re-engage, when it's off, it's off. Does the dial-based setting operate similarly? Fiat/Steyr are not daft and would surely extend this basic protection to the Cross, since this is absolutely foreseeable?

Or am I up a tree on this?

Not quite: 4x4 is available at any speed, and if 4x4 mode is manually selected, will be engaged. But the availability the ELD function switches off at 30mph (even if the light on the ELD switch or mode dial in the Cross says it's on)... and then is re-enabled as the speed drops back through 30 again. (That bit is explained in the handbook).

There's another of cleverness too - the MSR function ('Motor Schleppmoment Regelung', apparently!), which prevents wheel lock-up if you try and use too much engine braking, by briefly raising the revs slightly to get the wheels turning again.

There's a heck of a lot of cleverness in these cute little beasts.

 

[Harvie]

Forum right as usual in end. Gearbox guy said take propshaft off and it ll run quiet. Propshaft goosed as forum suggested. Thanks running 2 wheel drive just now

 

[JayAre]

The other thing selecting the 'off road mode' does is allow the diff lock to work if it needs to. For example, if one wheel comes up off the ground (such as when the diagonally opposite wheel drops into a hole or gully), that wheel will no longer have grip and so will spin freely. Because of the way a differential works, that will mean the wheel still on the ground will have no drive sent to it. The ELD system puts the brake on that spinning wheel which allows the other to drive again. This is the main (intended) purpose of the ELD button or 'off road mode' selection: to allow that diff lock function to work. The selection of 4x4 is fully automatic in the 'auto' mode and rarely (if ever) needs to be forced.

Just to clarify, the ‘slip’ test videos for the Panda 2012+ 4X4 system show that ‘normal/auto mode’ will allow traction to be transferred automatically to the other axle “if one wheel comes up off the ground” therefore obviating the necessity to engage ELD. However, the test showed that ‘normal/auto mode’ fails if 3 wheels have no traction (3 wheels spinning freely) which, I suspect, would be pretty rare for most of us most of the time

5 ‘zero grip scenarios’ were tested:

1. Front - both zero grip
Auto Pass
ELD Pass
2. O/S - both zero grip
Auto Pass
ELD Pass
3. F O/S R N/S (diagonally offset) - both zero grip
Auto Pass
ELD Pass
4. All except F N/S - three wheels zero grip
Auto Fail
ELD Pass
5. All except R N/S - three wheels zero grip
Auto Fail
ELD Pass