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Discussion Starter #1 (Edited)
Hi every1,

Recently (since month or two) I had this issue that there was a lack of power in my 159 2.2 its. Once you could have felt as it`s properly accelerating but sometimes it was like you have 50 hp less. FES did not show any errors.

I know sty similar can happen when the timing chain is to be changed but mine was changed like 20-30kkm ago.

Yesterday when starting engine in the morning I`ve got "have engine checked" light on. FES showed "P0016 phase synchronization (exhaust)/ revs". I don`t feel any difference in engine work however.

What can that be?
 

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In the parameters section of FES, tick both the Exhaust Phase Variator Desired Value and Exhaust Phase Variator Actual Value boxes. The software will now display the value the ECU expects to see and the actual value determined by the sensor on the exhaust camshaft. It might also be helpful to view the parameters as a graph.

The likely reason for the code is that the values don't match (i.e. the cam isn't where it should be relative to the crank) - either at some load/rpm point or across all load/rpm combinations. There will always be small differences and the actual value will lag slightly behind the desired as the hydraulics catch-up. What we're looking for is a difference of several degrees in steady-state operation.

Diagnosing what's actually wrong mightn't be simple as there are a number of possibilites that could cause the problem. E.g. basic cam timing (pulley a tooth out) failed phaser unit, failed control valve for phaser unit or failed cam sensor. Each of these would show up differently in FES and all but the basic cam timing could also be intermittent.

Some pointers:

1) Cam sensor failure - no data in actual value or unfeasible values
2) Basic cam timing - difference between desired/actual values when the phaser can't move the cam far enough to compensate for the pulley being misaligned. Also possible constant difference between desired/actual values
3) Faulty phaser/ control valve - variable differences between desired/actual.

Not sure if the control valve would throw a separate code if faulty - would depend if it's a hydraulic or electrical issue.

HTH
 

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In the parameters section of FES, tick both the Exhaust Phase Variator Desired Value and Exhaust Phase Variator Actual Value boxes. The software will now display the value the ECU expects to see and the actual value determined by the sensor on the exhaust camshaft. It might also be helpful to view the parameters as a graph.




Some pointers:



1) Cam sensor failure - no data in actual value or unfeasible values

2) Basic cam timing - difference between desired/actual values when the phaser can't move the cam far enough to compensate for the pulley being misaligned. Also possible constant difference between desired/actual values

3) Faulty phaser/ control valve - variable differences between desired/actual.



HTH

I have this error also on a 159 I picked up last week.

Took it to the local garage who identified a sensor was flatlining.

Have since connected up multiecuscan and found the Exhaust Phase variator position and expected Exhaust Phase variator positions sit at 0.000 deg on tick over.

The engine seems to run smoothly although not sure about the power as have nothing to compare it against having just bought it.

I've picked up a camshaft speed sensor 93183528 in the hope it might be the right one to fix this.
 

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Have replaced the sensor which appeared to be physically identical, cleared the fault code with Multiecuscan but within a few start stop short runs P0016 was back.

Due connectivity issues with Multiecuscan (after I paid for it!) I ran a check of Exhaust Phase Variator Position (Measured) / Exhaust Phase Variator Position (Actual) using the demo version of AlfaOBD and found for a great deal of my outbound journey of 15 minutes, the readings for both remained at zero.

My return journey captured more activity which I grabbed on screen before the 15 minute time was up.



They don't match when they do show, so perhaps the chain is stretched (after less than 30k), or something else is wrong which triggers the blank spots.

Is a zero reading expected or does this suggest a wiring issue?

Hoping to get Multiecuscan up and running again to get some decent readings with both the old and new sensors, but posting this up in the meantime in the hope someone might have an idea!
 

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P0016 has always signified a replacement chain AFAIK.
Perhaps every single associated part wasn't replaced last time?
Mine needed doing after 45k; I guess it's not inconceivable that it'd need doing after 30k.
 

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P0016 has always signified a replacement chain AFAIK.
Perhaps every single associated part wasn't replaced last time?
Mine needed doing after 45k; I guess it's not inconceivable that it'd need doing after 30k.


This was my first thought but when the local garage told me the sensor wasn't reading anything has raised my hopes in that it sensor isn't telling the ECU the truth.

Still doesn't add up that I'm getting flat spots of the graph, surely it should always be reading something?
 

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P0016 has always signified a replacement chain AFAIK.
Perhaps every single associated part wasn't replaced last time?
Now I'm home I can confirm the service history states that 3 years and 24,356 miles ago all this was changed..

71739677 Inlet Camshalf Gear
71753047 Exhaust Camshaft Gear
71773493 Electro-Valve Inlet Cam Solenoid
71773494 Electro-Valve Exhaust Cam Solenoid
55187973 Camshaft Position Sensor
71739327 Timing Chain

Combine this with the fact I'm getting sporadic zero readings, it might be..

1) Cam sensor failure - no data in actual value or unfeasible valuesHTH
Can anyone confirm what they see on their healthy engine? Do you also see zero values for Exhaust Phase Variator Position readings?
 

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That's nearly 25,000 miles - 40,000km.
If the oil changes haven't been regular enough and with the right grade of oil your chain could certainly be toast. Don't believe the recommended interval, they're far too long to ensure chain longevity.
Also, in the parts list there's no mention of tensioners or guides being changed which I'd rate as a necessary when the chain is done.
Bit odd that the electrovalve and sensor was changed but not the guides and tensioner.
 

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Not good seeing guides & tensioners not being changed with a chain. Thats bad practice. Its standard practice if it was done under warranty though.
 

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Looking closer at the service records for that period I see no evidence to suggest the tensioners nor guides were replaced, if they did they didn't invoice for them!

I'm fully prepared to get the chain and auxiliaries replaced, however I've read horror stories where this has been done only for the fault code to return suggesting the chain was fine.

With that in mind I first need to confirm the sensors are working correctly, and so understand what a zero reading for the Exhaust Phase Variator means.
 
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