I have exactly the same on my 1.9 jtdm. (2006 56 plate).

It seems to be coming from the fuel filter and goes away for a few seconds if i waggle the filter..

I'd love to know what it is. Its definitely not the fan.

James

 

oh ok thanks james,

i haven't heard it for the last two days... my alfa is a 1.9jtdm 06 as well.

 

I found that mine makes the fan making noise at idle, but only when the air con is on. I have the 2.4 JTDm

Salute, Giordano.

 

I have an 06 plate and have also had this noise....very annoying when the car is silently cruising.

It sounds like a vacuum cleaner type noise behind the dash.

It is definitely the fuel filter or more specifically the pipes connecting into the top of it. If you open the bonnet when it sounds you can feel the vibration on the pipe. As soon as you hold it the noise will stop.

I had a bit of a poke around with the offending pipe and it stopped it for the rest of the trip home...have to see how it goes tomorrow. At least it is nothing serious as I first feared!

 

I'm glad its not just me that thinks its the fuel filter. Why on earth would the fuel filter make such a noise?! I wonder if it could be a symptom of the fuel pump from the tank and/or the high pressure pump? Vibration being passed on through the pipework?
Lets assume not for the time being...

James

 

Has anyone sorted it out yet, if it seems to be a small job. I would prefer to do it myself.

 

I had similar noise; amazingly it was a rubber hose vibrating on a piece of plastic by the fuel filter.
I just used some black electricians tape to secure the hose and voila!!
Few years on and that piece of tape is still there doing its job.

 

I got a similar noise on mine while out yesterday but it only happened under moderate to hard acceleration.

Turning off aircon and heater fans made no difference so I was getting worried.It also didn't do it blipping/holding the throttle whilst stationary.

I think Gus changed the fuel filter at the last service a couple of months ago so something may be slightly disturbed. Relieved (so far) it sounds relativley minor.

I hope I found the right thread!

 

So its happening when the engine is warm (cool in the morning, cooled by moving air when driving)?

I had similar on my 156 diesel when it was stopped in traffic. The problem was the 1st fan control resistor had broken - there are 2, one for each fan - and so it was skipping striaght to the Big Fan, which normally only cuts in when really hot, and is quite loud.

Incredibly, the resistor is a big ceramic thing which snaps off after a while, can that have carried over to the 159? Even if not, sounds like your fan controlled, best get it looked at now its getting warm outside

 

I know what you mean about the resistor thingies. I know the MK4 Golfs had a very similar problem. However, I really think this sound is coming from around the fuel filter. It definitely is on mine anyhow. If I waggle the filter it stops. Really strange. Almost like there is a loud electric motor inside the filter itself.

James

 

Mine went into limp home mode today and had the check enine message on the OBD. Can't do much over the holiday unfortunately. Still driveable but very down on power.

 

My Saab (with the exact same engine) sometimes goes into limp-home mode. If you do a number of restarts which the car considers go be "good" with no faults detected, it will clear the engine light and take the limp-home mode off. I think 10 or 20 good starts does it. I just start the car, let it run for a couple of seconds, turn it off, remove the key for a couple of seconds, reinsert, then repeat a number of times.

Its worked well a few times now. Could be worth a try.

James

 

ive just had my air con regassed as it wasnt cold. Now i notice a metallic sounding fan noise which comes on occasionally when I have the aircon blowing cold air.... Maybe it could be your aircon? Have you recently started setting it to cold with the warm snap we are enjoying?

 

No, I usually leave it on auto tbh. It's still cold. In my case the "fan noise" rises with throttle opening and engine power has dropped off now it is in limp home mode.Immediately prior to that I had noticed slight hesitancy on the throttle.

 

Update:

Bauer Millett gave it the once over and found it was a split turbo hose (two days to order ) and the dpf was clogged too so did a forced regen.