Technical JTD making a noise after turning off

[sussexa]

I'm not sure on your location but the 150jtd was nice and visible with bumper off looking from n/s wheel to radiator , I had the intercooler off at the time though. You could probably feel around it on ramps from underneath, not far from where you fit air filter. Follow pipe back from turbo actuator(approx 6mm pipe).

 

[TangerineTractor]

Is it something that will have to be replaced, or can it be cleaned up/repaired?

 

[sussexa]

Search boost valve , if it is that. That amount of noise should be easier to trace.
https://www.fiatforum.com/stilo/276358-boost-control-valve.html

 

[TangerineTractor]

Is this the part? http://www.carparts4less.co.uk/cp4l...7353daabf9814645f4ac2f1baed5f5fb85997b&000525

They don;t list the part number, and refer to it as a Pressure Converter...

Same as here: http://www.worldcarparts.co.uk/tabi...tm_source=google&utm_campaign=google_shopping


Edit to confirm: Just been on to car parts4less - they say that the pierburg number is 7.21903.48.0 and it matches up with the fiat part numbers...

 

[TangerineTractor]

OK.. time for an update...
Bought a cable and hooked up FES - the engine fault was the MAF, so nothing to do with this noise.
Anyhow, kept my eye on ebay, and found someone selling a boost valve from an Alfa they were breaking - it's the same part, and they wanted 40 quid, but I offered them a tenner on best offer, and they agreed! So I'll get that swapped in when it arrives, and let you know how it goes.

 

[TangerineTractor]

OK. Now my head is about to explode.
Got a replacement MAF and fitted it yesterday, and cleared the engine fault with FES. Car is running better than ever now, nice and smooth, decent MPG.
But here's the interesting bit: THE NOISE HAS STOPPED!!!????

WTF? I fitted a new MAF. The noise was there with the old MAF in situ. The noise was still there with the MAF disconnected. So the noise did not, and couldn't have possibly come from anyway, come from the MAF. So why the hell has changing the MAF stopped the noise? And what do I do with the Boost Valve that I bought but haven't fitted yet?

I'm kinda half-hoping that the noise comes back, because this is just doing my head in now. Somebody give me a logical explanation!!!

 

[Shadeyman]

Just a guess but a faulty(or disconnected) MAF would cause the ECU to run the engine in a sort of default mode. Perhaps this default mode limited certain things like turbo boost etc. In which case the sound of the engine would change once the faulty MAF was replaced and the engine is running as it should.

 

[TangerineTractor]

The engine running is fine - it's the dying duck noise after turning off that has suddenly stopped after replacing the MAF... of course the noise stopping could be completely unrelated, but it seems like too much of a coincidence.

 

[Shadeyman]

The "dying duck noise" could be the boost valve venting?

 

[TangerineTractor]

Yeah, we'd already concluded that it was probably the boost valve, hence the reason why there's a new boost valve sat in my garage waiting to be fitted - but why would fitting a new MAF stop the boost valve making a noise on shutting down the engine?

 

[Shadeyman]

I dont think it would but I suppose its possible. :shrug:

 

[TangerineTractor]

Scrap that. The duck was back tonight...

 

[richydraper]

*chucks some bread down leaving a trail from your front door to your local pond*


kinda scuppered if you have a pond

 

[TangerineTractor]

An update:

Got a second hand boost valve for a tenner, and my mechanic fitted it for a tenner... noise all gone, the duck is dead.

So thanks to those who offered assistance and pointed me in the right direction.

 

[FiatFleetFamily]

Not that I have this problem yet. Where is it fitted in the engine bay, so that if I do get this problem, I know where to look..

 

[TangerineTractor]

Its mounted on the front of the car down by the air filter - very tight to get to - my mechanic took off the main air inlet pipe and got to it that way, the other option is through the wheel arch I would imagine.
It's only two pipes and a connector, and is held on with two screws. There's a guide somewhere about relocating it to avoid it getting over-exposed to damp etc, but I figure that with the undertrays etc in place it should be ok, and this one lasted 80K miles...

 

[Muppet1]

Funny that you should have posted this, I have a Vw T5 1.9tdi with this exact noise and kinda knew is wasn't serious.

Now i know.

 

[Grobar123]

Hey brothers.I'm new member on this forum. I am reading you and I have the same problem like you. You solve the problem ? What was the problem? I'm reading it was Maf, then it was not the Maf..and now ? Please help me, a don't know what is that noise, it sounds like farting..Bruh..
Please tell me, it's that serious ?

 

[Peat]

Welcome.

If you check the previous post date you will see it is just under four years old!

But having said that your question is still relevant - There is nothing to worry about as far as I can see.

It only occurs on my JTD when I have been running with the A/C switched on. At all other times there is no "running down" noise!