WRX Blues

I had my car serviced 4 weeks ago and a week later I checked the oil level on the off chance. It appeared to be very high. That said, the car seemed to be fine.
However, over the last 2 weeks the car has been behaving very strangely under full throttle specially in 4th and 5th gear. For example, if I apply any throttle in 5th gear the tacho leaps around 1000rpm and then drops back down again . It almost feels like I am riding the clutch.
I am fairly certain this must be connected to the ecxcess oil as the PSI data monitor is not finding any fault codes.
What has happened and what do I need to do? IO have searched but advice is confusing as potential overfill problems seem to cover everything from MAF, to boost hoses to Intercooler?
I will take the car back to the dealer but want to know what the solution is before I let them c*ck up again!

martiboy

Sounds as though your clutch has started to slip.Maybe nothing to do with the oil and is just a coincidence ???

scoobycraig

Obviously they need to drain some of the oil out first. The funny behaviour may be caused by oil overflowing in to your boost lines/ intercooler. If you've got the basic tools just take the intercooler off and see if you can see any oil??

SSCJAY

Sounds more like clutch slip to me, accelerating in 4th & 5th will be where the most torque will be put through the clutch