JTDm Hesitation at 1500 RPM

[SimplePeter]

Hi All,

I've had my first alfa for around a month now. 2009 159 2.4. It has 135k on the clock. I've noticed that every morning when I first start driving, there is a noticable hesitation between 1500 - 2000RPM, when driving around 40km/h at half throttle.

I did some reseach on the UK forum, and many people seemed to suggest the EGR valve is the cause of all my woes.
So I found a couple of tutorials, and removed the valve today. Gave it a really good clean and re-installed it.
It was not terribly clogged up like some of the UK examples. Perhaps the fuel in AUS in better... Anyway, the valve certainly moved more freely and smooth and sealed better once I was done.

Unfortunately I just took a test drive, and the issue is still there

I'm interested to see if anyone else has had this issue, and what the fix was?

Thanks in advance!

[Mick A]

Hi Peter,

If you remove the plastic cover on the engine, have a look down where the glow plugs are fitted to the inlet manifold, there are plastic arms which connect to a linkage which actuates the swirl flaps in the manifold, I do see that linkage break sometimes, or the swirl flaps themselves leak air and cause a fair bit of muck to build up on the exterior of the manifold. Normally cylinder 5 fails first due to being the one that is operated by the actuator and link rod, then it bears the load of the other 4 cylinders.

I would also say for having done 135,000km, if the car hasn't had a manifold replaced yet, it's probably full of awful gunk, and the back of the valves will be the same, so this really does affect engine performance.

Running an upper engine cleaner through the system can really help things, but only if there are no leaks etc.

Also check the boost pressure sensor on the back of the manifold, these get full of gunk and stop reading correctly sometimes. So many little things can affect the correct fuelling of the Diesel engines, resulting in poor start ups, to loss of power, to rough running. The engines themselves are almost bulletproof, but it's all the anti pollution crap that lets them down.

Another thing would be to check the differential pressure in the particulate filter, you'll need a scan tool to do this. Basically it's checking back pressure from the DPF.

Cheers hope this was some help, this is just a brief run of ideas there are more but no point going crazy straight away!

Mick.

[SimplePeter]

Thanks Mick!

I'll check over these things on the weekend.

Peter.

[J159]

Hi Peter, this sounds exactly like what I was having issues with last year. Noticeable loss of power low down and jerky, almost bringing the car to a stop when changing gears at low speed (more noticeable when cold).

I took it to one of the specialists here in Sydney and had the EGR/manifold cleaned, ran like a completely different car afterwards.

[SimplePeter]

Thanks J159.

Can I ask how much did it cost to have the intake cleaned?

Thanks