E270CDI Limp Mode

[c43 merc]

Hi All,

I have a 2003 E270 i am having a few issues with at the moment, it keeps going into limp mode everytime you use the turbo, the car will go into limp mode but if you switch the car off and restart it will be fine again until you use thr turbo again, this will happen a few times and then it will log the fault and the check engine light will come on the dashboard, i have a generic fault code machine and the code it brings back is P0034, which is 'turbo bypass valve'

I have read through countless threads and all have differing answers, to date i have changed the following but i am still having the same problems.

1. Turbo bypass valve off a working car
2. Full exhaust system but not the first cat attached to the turbo
3. Air mass unit

I have had the intercooler off and can't see any obvious issues with it and i have also made sure there are no leaks from the pipes when i refitted it all back together again.

Please can a anyone help me with this as it really annoying!!

Thanks

 

[Azeem]

https://www.mbclub.co.uk/forums/engine/144927-lack-power-cdi-what-do.html

Have you checked the turbo boost pressure? Please share the values.

 

[David404]

Have you had the car on a Star machine or a generic code reader. If just the latter suggest getting a local indie with Star machine to read codes.

 

[m11nch]

I had a few ml270s and if it's the same engine I would check
The boost pressure I made up a bake bean tin and rubber hosewith a bike valve to pressure test the system
Also maf sensors are common to fail and the egr valve gungs up throwing up limp mode
But like the last post star machine would be the least costly
Answer as it takes out a lot of guess work