2008 159 2.2 JTS Lumpy Idle

[johnts]

Hello, new to the bb.
Have owned this great car since 2010 with no real issues until now (oil and filter changed every 5k btw since ownership).
For a month now I've noticed a lumpy idle (cycling between 750 to 1000 rpm).
Sometimes more severe.
But the behaviour is random.
No apparent loss of power under normal driving.
multiecuscan error codes are below.
Any assistance greatly appreciated.
BTW - if I decide to replace the coil pack how on earth does one disconnect the cable at the end of the coil pack ?
Thank you!
John from Sydney Australia

Bosch Motronic MeD7.6.1 CF4/EOBD Injection (1.9, 2.2)

p303 (cylinder 3) and p304 (cylinder 4) ignition failures
p300 ignition failures generic
p1141 preheating resistance 1 below catalyser
p0139 lambda 1 signal below catalyser (slow)
p1176 mixture 2 strength (additive) (fatal)
p1173 Mixture 1 strength (additive) (fatal)
p0013 Phase variator actuator on intake shaft
p0159 lambda 2 signal below catalyser (slow)
p0505 idle control
p0136 lambda 1 signal below catalyser
p0011 Positioning diagnosis of camshaft on exhaust
p0016 Phase synchronisation (exhaust)/revs

[Mick A]

G'day John,

If it were me I would record all the details of the DTC's, then clear the codes and drive the car again until you get another engine light, then re-check the codes and you'll probably find only one or maybe two codes have returned. These will be the codes that are most likely to point you in the right direction.

I suggest this because sometimes one failure can trigger a chain reaction and send other sensors out of range so then the computer throws another code to the list. And then this can repeat again, so you end up with a heap of misleading codes created by the original failure.

How many km's has the engine done with it's current timing chain?

Cheers! Hope this was of some help.

Mick

[johnts]

Thanks Mick.
I've cleared the codes and will keep a look out.
Engine does sound a little rattlier than normal...I think...
Car is at 104000km and the chain has never been replaced.
I can do very basic things, so is the chain something I can do?
I know the 2.2 is easier than the 3.2.
Thanks again.
PS. Any links to good workshop manuals anywhere?
I mean I bought a Gregory' service and repair manual for the vs commodore.
Is there something similar for the Alfa?

[Mick A]

Hi John,

I would almost guarantee it is the chain at those km's.

And possibly also the variatior solenoids, they tend to fail after so many km's too.

The chain isn't a basic job, so I would recommend you trust the job to a qualified mechanic.

I've replaced many timing chains on the 2.2's,  and I recommend replacing the balance chain tensioner at the same time. Also replacing the gasket for the engine front cover plate as the oil pump is built into the timing cover and it is important for a good seal for oil pressure to be correct.

For now, I still suggest do nothing for the meantime and just drive it normally and wait for the codes to come back, then we can work out which direction to go from there.

Mick.

[johnts]

Thank you.
In the end it was a vacuum leak.
Obvious to my mechanic when I turned the engine off and the distinct hissing would bleed away.
It was a torn diaphragm in that round housing above the inlet manifold housing.
(Apologies for wrong terminology).
My mechanic simply squeezed with his fingers, the smaller rubber hose that connects to it, and the idle settled at 800 immediately while the engine was hunting the idle or settling the idle at 1000-1200 rpm.
(That's where I felt dumb after hours of my internet researching :-)).
Anyway, 2 minute job, $200 part :-)
BTW, service schedule book that comes with the car, mentions nothing about chain replacing, I mean, like never!?!?
But I should replace it eh? Can you hear warning signs?
Thanks again.