Hello folks,
a friend of mine is driving a Volvo 850R with 70k on it. A week ago all the power disapeared. A check engine light came on and showed bad O2 sensor. I can't believe that the turbo is out. When we got the car it wasn't using any oil. After we changed to Mobile One, the oil started disapearing. Do you think that it's possible since the O2 is bad that it's sending bad info to the ECU which ,on the other hand retards the timing and let's all the boost out in advance trough a valve? I don't know what to think. Any help of input will be great. Thank you in advance!

 

If there's no obvious oil seepage anywhee then you my point to the turbo as burning oil. Sometimes when you switch to synth oil it cleans old oil deposits and new leaks can develope. I just got my 850 10 days ago so I don't know much about the OBDII diagnostics (o2 sensors) maybe "tech" can help you there. I would definetly look for new oil leaks though or have the compression tested, also check for vacuum leaks!

 

Replacing the O2 sensors are the first thing to do.Then look at the induction hoses.If there is a hole in one of the hoses it will lose all power.