I have a 1.3 MJ diesel engine in a 2008 Fiorino and when running there's a kind of dry bearing noise when not under hard load.
Its present at tick over and deceleration but not when under hard load. Its also present even if the clutch pedal is down or up. You also can't hear if from above the engine only when in the van. Its also present when stationary which eliminates the wheel bearings.

If anyone has any ideas I would appreciate your views.

Belt tensioner (timing or auxiliary) or water pump?

Hard one to pinpoint without hearing it.

As DaveMcT - possibly idler pulley on aux belt as a favourite - but just guessing really. An old fashioned listening rod would help (or long screwdriver).

Yes. I'm guessing but they are the likely culprits. Another could be the alternator. Ive had whirling noises (like a failing washing machine bearing) from an alternator. It seized up shortly after. On that occasion, the alternator case was visibly cracked as well.

A long screw driver should allow you to listen for the source.

Thank you guys and sorry for the slow reply but a new job and long hours etc etc. I have to say that you're probably right as its coming from that are within the cabin.

One more thing whilst I'm here, when I picked up the vehicle which obviously had a cam chain issue I noticed when pulling out of a junction under load that there was a kinda clacking from the engine and loss of power. Now that the cam chain has been changed and now much quieter its still doing it. Even at under 2K revs and laboring the engine it gives of what sounds like what I imaged was a bent valve hitting the piston crown, yet when out of gear and unloaded it revs right out as normal, nothing unusual.
Oh and I can slowly get through the rev range in gear along the motorway if I take it through the rev range slowly, its only when over gassed.

Thanks in advance.

Because it is a diesel, there is no vacuum in the inlet manifold, so there is a vacuum pump to operate the brake servo. These do tend to clack a little at times. They do also have a tendency to become loose on their mountings, on many vehicles, not just Fiats. So worth finding it and having a check. Find the brake servo, follow the vac pipe from it back to the vac pump.

Catastrophising warning -

I had a Montego diesel that developed a ticking from the gearbox end of the engine. After a while I was able to tell there were two ticks per crank revolution but the screwdriver listening test found nothing at the cylinder head.

Having been a 2 stroke bike fan I suspected a small end bearing. I dropped the oil pan and found bits of piston skirt in the sump. The skirt had cracked around the bottom piston ring allowing the fragment to clack at each end of the stroke.

So that was a cylinder head-off job to replace the piston. The bore was clean and no damage was found anywhere else. The small end was fine as well.

Budgie Smuggler said:

when not under hard load.
Its present at tick over and deceleration but not when under hard load.
You also can't hear if from above the engine only when in the van.
.

Click to expand...

Sounds a lot like the big end bearing


Need to get under the car and listen around the sump.


Often sound worse through the roadwork on a motorway. The sound bounces of the concrete barriers and through an open window.

Thank you guys.
It's definitely not a big or small end and last night I purposely overgassed entering a motorway from a slip road with head lights behind me. I noticed at the point of this very loud clacking that some smoke came from the exhaust, or maybe unburnt fuel?
Does anyone have a workshop manual so I could have a look at the timing mechanism?

Oh and I remounted the air pump when changing the cam chain.

You might have an injector that's not spraying properly but TBH it does sound like a mechanical issue.

They are common rail so can be unplugged one by one. The engine will run unevenly but if the noise stops that would be your fault.


Bearing in mind you have fitted a new cam chain there might be rebuild issue - tensioner, timing out by one tooth, etc

Re: Multijet Noise

Well I've bailed on Fiat. I've never experienced such poor build quality and constant mechanical issues. Its been a money pit from the day I purchased it.

Just bitten the bullet purchased a new Japanese Nissan Tekna NV200.

Thanks to all who contributed during my wrestling with the Fiorino and good luck!