Technical Fiat Panda Cross 4x4 '07: Loud humming from engine during load

[BKD]

Tried searching for this, but came up empty handed.

So I'm having trouble identifying the cause of this issue here. In highway speeds and with heavy load (like 4 people in the car f.e.), my 4x4 is making such a noise when putting on the throttle. At around 100-120 kph and 2500-2800 RPM, if I put any amount of throttle I start hearing a loud humming noise that resonates incredibly in the cabin.

Sure, I know the engine is under load and stuff, but the humming really gets so uncomfortably loud that I cannot imagine this is normal behaviour. The sound really fills the cabin to such a degree that I'm having trouble discerning where it could be coming from.

It's Fiat Panda Cross 4x4 with the 1.3 Multijet engine. I know this is a vague question, but I don't even know where to start. Anyone recognize this?

 

[A3jeroen]

Some heat shield on the exhaust resonating?

gr J

 

[koalar]

probably not from the engine or gearbox

You can normally tell there from the front

Try opening different widows to tell where the sound is coming from

Prop shaft
Centre bearing
Exhaust

Would be my guess

If it’s from the centre you need to get under and give everything a good visual inspection
Then physical inspection.

If you can’t find anything it’s possible to remove the prop shaft and test as two wheel drive.

 

[DaveMcT]

Engine have a noise resonance that occurs around the gear shift points. When the silencer internals fail that noise can get very loud.

 

[koalar]

Start the engine

Put your hand over the exhaust

Does the pressure build up and can you hear any leaks

 

[koalar]

Does your exhaust have a centre box

Might be different in Sweden.

The 1.3 does here in the uk

 

[varesecrazy]

Hi

Are you on snow tyres ?

The engine Rpm is where the Turbo really starts working.. so plenty of 'torque reaction' to set off vibration

 

[BKD]

Thanks all for the replies! Will do a walkthrough and get back with results.