Valvetronic nightmare

A

Andrew Sheldon

Member
 South West France
OK.. I had to fit a new expansion tank, all went well, however when I came to start her up she ran really rough.. like it was in a limp mode.. Under inspection I found the valvetronic plug was not plugged in.. I don't remember unplugging it and there was certainly no need to do so to replace the expansion tank... cut a long story short she ran better after I plugged it back in, especially after initial start up, perfect... But after a short while it ran rough again, sounding like it was misfiring on 1 cylinder.. I replaced all the coil packs and plugs but it was still running the same.. It ran fine for about a minute then chug chug.. It did this a few times.. Messing about with it I found if I unplugged the motor then plugged it back in whilst the engine was running the car ran fine again... My question is am I simply disengaging the valvetronic completely by unplugging and plugging it back in or is it resetting itself... I have read forums that have said they have disengaged the valvetronic completely at the expense of slightly poorer performance and fuel echonomy. I have obviously got a problem, weather it is the Eccentric Sensor or something more serious...
Is it possible someone disengaged the valvetronic completely and I've been running the car without it.. I did notice I was getting poor mpg...
 
Yes will do, got to get a code reader first....that's on the to do list... however is it pos to disengage the motor and the car to still run fine.. ?
 
What engine do you have? Unplugging the eccentric shaft sensor is a well known trick to run the valvetronic on default values, but I didn’t think the engine could run with the valvetronic motor unplugged. There is a backup throttle servo that I guess it uses under those circumstances but the engine will be running a long way off from peak power and efficiency. I assume you get a dash light on also?
 
I unplugged the eccentric shaft sensor made it run terribly.... however unplugging and plugging back in the valvetronic motor does the trick... however you have to do that every time you start the engine.... well confused hence the nightmare..... lol... I have the 2.0i engine.... the gonky one... thanks for your replies btw.. no one has come back at me re effectively turning off the valvetronic system.... nerr mind...
 
Andrew - I had issues with my valvetronic actuator recently and managed to change it myself, you can get one on ebay for around £35, except youl also need to get a new rocker cover gasket. Although mine leaked 3 times since and I went back to the old one with some gasket sealant.
There's a good video on youtube which shows you how to do it.
https://youtu.be/PTK60po-2HU

Might be worth replacing it youself.
 
Did you replace the rubber cushion washers underneath the cover securing bolts?
These do go hard with age and shrink, fitting a new main gasket without changing the washers out may well cause bad sealing and result in leaks from the main gasket. Best to replace gasket and washers.
 
Thank you for your replies.. I've actually worked out my own answer using trial and error in that you can run the car with the valvetronic motor disengaged so long as the valves are in a good orientation, Not sure where that would be, probably somewhere in the middle I would guess. Yes your performance and fuel economy suffers but the car runs fine apart from that. Reasonable acceleration and a good idle, no stuttering and no misfire. When I bought the car someone must have disengaged it on purpose knowing the eccentric shaft sensor was faulty..
I have read many posts saying that one day the car runs ok and the next its poorly, if the sensor is faulty it can throw the motor into different positions either opening or shutting the valves too much, or as I have found a happy medium where everything seems ok even though it is not..
Don't suppose any of you kind gents and ladies would have a sensor for sale...
 
You must log in or register to reply here.
Back
Top Bottom