Engine fault.

[petercronin]

I had a struggle a while ago finding the part number for the o2 sensor, the only way you’re going to know for sure is to get under the car and have a look.

 

[turkie172]

The problem with all that is your experiencing problems with them and there is no guarantee the last person fitted the correct O2 sensor in the first place and I have said this many, many times never trust the online parts lookup sites even the motor parts shops either, as the Renaultsport cars are nearly always wrongly listed and you end up with a part that fits a standard Clio and not yours. Always get the Renault part number first and then cross reference it to another manufacturers part the Lambda sensors for example just about over £100 each by the Renault part number Bosch make the genuine ones and I got both mine for £90.

 

[John Gordon]

Hi All,

Just thought that I would update this just in case anyone else has the same problem in the future. I have now fixed the car (With somewhat of a bodge for now) and no longer have the error codes from the ECU.

Basically. When my dephaser was worn, pre cambelt change, it would sometimes rattle horrendously when cold starting in the mornings. (Sounded like a spun bearing). This rattle would last a few seconds then stop once the oil had taken up the slack in the dephaser.

It was this rattle motion in the dephaser (Rattling backward and forwards on the inlet cam) that had acted like a hammer drill and it spun the trigger wheel on the inlet cam (so that it was no longer in a workable range).

I've managed to move the trigger wheel back around 5-7mm counterclockwise on the inlet cam and now its back within range, I get no ECU errors and the VVT is working again.

So. Long story short. If you'ver got a cam position sensor fault that you can't shift, there is a chance it may be the trigger wheel on the in inlet cam that has shifted.

 

[turkie172]

Would you think that if the trigger wheel (and I'm not sure what part that is at the moment) was out and you moved it now saying 5 -7mm does not sound like a proper engine builder type spec. I would get the engine checked components would have been stressed maybe valve and the timing your still not sure about. Leak/ compression test possible light head rebuild/ inspection or exchange it's not worth loosing the whole engine over it.

 

[John Gordon]

Would you think that if the trigger wheel (and I'm not sure what part that is at the moment) was out and you moved it now saying 5 -7mm does not sound like a proper engine builder type spec. I would get the engine checked components would have been stressed maybe valve and the timing your still not sure about. Leak/ compression test possible light head rebuild/ inspection or exchange it's not worth loosing the whole engine over it.

What I mean by trigger wheel is the little piece of metal with Tabs that the cam position sensor reads.

I had a theory as to how it had gone wrong and it seems I'm right.

To fix it, this weekend I took off the inlet manifold, removed the cam position sensor and used a little 'bar' to turn the timing wheel back anti-clockwise on the cam (thinking that the dephaser would have spun it clockwise).

You're correct in pointing out that it's not exactly scientific. But, my ECU is now happy that the cam position is back in its 'range'.

I fully understand its by no means fixed, but I know for sure what the problem was now. To fix it properly I need a new inlet cam.

 

[turkie172]

I'm very glad that it seems to be running better and well done I snagged a picture of what your talking about. But just asking if the pickup is on the cam and it makes no contact with anything how could it move surely the cam is in the wrong position or the pulley on the end. The possibility I would be looking at if the engine never ran fine or developed the running fault after the timing was serviced I cant remember, but is there a chance the car has aftermarket cams fitted or the ecu was setup for aftermarket cams. I've never fitted aftermarket cams or know the process of setup and I don't know how far you can be out on the setup and cross the line from running bad and engine damage you may have adjusted the ignition timing and the damage has yet to appear if you understand.

 

[John Gordon]

I'm 99% certain that it's not in the correct position. The only way to be sure is to replace the camshaft. But the ECU is happy with what's it's now got to work with and so it's given me VVT back. Which is just fine.

I know exactly what you're saying though. But I don't think there's anything that could go wrong. If you think about it. The ECU has already shown that it looks after itself if its outside of a predetermined safe range. (The ECU faults were, "Cam position sensor outside of range", "Cam position sensor outside of range for pollution standards", "Cam Position sensor program stops")

And as for what moved it. My theory, which sounds a bit mad. Is that the clacking backward and forwards that my failing dephaser made in the cold winter mornings was enough to "wiggle" The wheel around and out of tolerance.

 

[Foxspeed]

its still not accurate or in the correct timed position and therefore in the long term could still cause issues with incorrect fuelling/timing...

yes the "clack" could cause vibration for it to move but again its not very secure if its moved by that issue...

but as you say its running ok so if it does go "pop" then its your decision