2.5i limp mode- thoughts?

[bigwinn]

Afternoon all

Long story told short with this 2003 2.5i manual:

Came with an engine issue: car goes into limp mode when warmed up and under load. So you cant do this revving it stood still. When it goes into limp mode it obviously throws codes and revs fluctuate 1k-1500rpm.

Initially I thought the DISA was the culprit- it was in an awful state and wouldn't move- replaced- but issue prevailed.
I swapped the DME over and coded the EWS out- as it was stating several DME issues- again didn't sort the issue
I looked further at the codes and saw several vanos codes- I swapped the solenoids over and that seemed to change things- but the issue still remained.

These were the codes present



Today with a rebuilt VANOS in hand I swapped it over- and lo and behold the issue was clear to see (note Ive never seen a vanos seal do this before!!!!). The exhaust piston was solid in the cylinder. I also changed the oil and filter to ensure that wasn't an issue.



Thats got to have sorted it right?

NOPE.

These are my new codes



Over to you guys for a view.

Steve thinks its oil pressure switch or an oil feed issue (checked oil flow at the vanos feed pipe and its good- very efficient at spraying hot oil everywhere)
Barry says its a MAF issue and when I get a sec I will unplug the MAF or swap it out to see if that makes a difference

I'm looking for a steer before I spend more bucks on parts...

Thoughts?

Cheers

Stuart

 

[Mike6]

A long shot but if your battery is old and failing you can get all manner of engine codes.

 

[bigwinn]

Battery is good- amps and volts

 

[enuff_zed]

[ref]bigwinn[/ref], I know we have discussed this off-line, and I know you have tried swapping the vanos solenoids, but just to confirm: did you check that the shuttle valves, that the solenoids act on, were free to move in against spring pressure with just the lightest push, and that they moved back out on the spring when you removed finger pressure?
It's difficult under load while driving, but are you able to view live data to see if the cam angles are moving correctly?

 

[bigwinn]

[ref]bigwinn[/ref], I know we have discussed this off-line, and I know you have tried swapping the vanos solenoids, but just to confirm: did you check that the shuttle valves, that the solenoids act on, were free to move in against spring pressure with just the lightest push, and that they moved back out on the spring when you removed finger pressure?
It's difficult under load while driving, but are you able to view live data to see if the cam angles are moving correctly?

Swapped solenoids around and tried new bud. Check spring action on both vanos units no issues

Good shout on seeing live adaptations.

 

[bigwinn]

Just to add- had all the ICV intake set up off cleaned etc

 

[enuff_zed]

[ref]bigwinn[/ref], I know we have discussed this off-line, and I know you have tried swapping the vanos solenoids, but just to confirm: did you check that the shuttle valves, that the solenoids act on, were free to move in against spring pressure with just the lightest push, and that they moved back out on the spring when you removed finger pressure?
It's difficult under load while driving, but are you able to view live data to see if the cam angles are moving correctly?

Swapped solenoids around and tried new bud. Check spring action on both vanos units no issues

Yeah, I thoiught you had tbh, but with these threads it's always good to add stuff for others with the same issue in the future.

 

[bigwinn]

I’m going to try a spare MAF, oil pressure switch and I’ve a spare exhaust cam sensor…

 

[enuff_zed]

I’m going to try a spare MAF, oil pressure switch and I’ve a spare exhaust cam sensor…

If that doesn't work, I have contacts at Esso and Swan Vesta. :roll:

 

[bigwinn]

I’m going to try a spare MAF, oil pressure switch and I’ve a spare exhaust cam sensor…

If that doesn't work, I have contacts at Esso and Swan Vesta. :roll:

:fuelfire:

 

[bigwinn]

Still trying to diagnose this

Replaced inlet and exhaust position sensors
Oil pressure switch
MAF

I’ll try to get a video up- drive the car sedately and no issues

Press the engine in 2nd or 3rd up to 3.5k revs and it goes into limp mode- revs fluctuate and displays ABS lights

I tried it with dtc switched off and the same happens

Any ideas? I’m running out of things to check

 

[enuff_zed]

In my head, something is not liking the signal telling it the engine revs are high.
Could it be a DSC/ABS unit issue. That looks for engine speed as part of its equation, along with steering angle, wheel sensor feedback and who knows what else. The DSC in its very basic form cuts power to stop you arriving at the accident backwards.
I'm thinking on the fly and just throwing thoughts at you, hoping someone can piece them together.

 

[bigwinn]

Makes sense.

I’m going to have a play with the laptop to see what happens if I clear codes etc

I agree it’s something linked to dsc or ABS

 

[Zedebee]

Is it linked to revs or acceleration. It could be related to one of the accelerometers rather than engine revs. If you rev it up to 4k while stationery, do you have the same issue?

 

[bigwinn]

Is it linked to revs or acceleration. It could be related to one of the accelerometers rather than engine revs. If you rev it up to 4k while stationery, do you have the same issue?

Nope- I can’t get it to do it while not moving

It’s another thing worth checking

 

[Zedebee]

I tried it with dtc switched off and the same happens

Have you tried it with the DTC fully off (press and hold for 5+ seconds) rather than just pressing the button? I know you know this stuff, just checking.

 

[bigwinn]

Yep I did- no change