I was driving my 2006 CS in the mountains yesterday, and as I was running through some curves the engine suddenly began losing power around 4500 RPM. If I shifted to the
next
gear and the revs dropped, it pulled strong again to around the same point, when it would do the same thing again--hesitation, power loss; it felt like I had hit the fuel starvation point at the rev limiter. After a bit of this, the car really had issues--I was in 2nd gear with the throttle over 50% just to keep it from dying. Car was sputtering and jerking from power on/power off of the engine. But I was on a very narrow and twisty back road and had to limp it to a scenic pull-off spot where I knew a flatbed could get to me. I parked the car and turned it off, tried to crank it again after a few moments, and was unsuccessful in starting it. Engine turned over but wouldn't fire.
Twenty minutes later the car cranked over with no issues, and I drove it 3+ hours home, taking care not to push it over 4k RPMs. I dropped it off at my mechanic's shop, but just before I did I went wide-open throttle on the interstate to see what would happen. Car ripped through the gears all the way to near redline and I easily took it past 130 MPH (in a computer simulation in Mexico, of course).
Has anyone else had an issue like this? My uneducated guess is fuel pump or injector or something like that, although I suppose it could be the coils or plugs not firing properly. I had just under 1/2 tank of gas, so there should not have been a problem with fuel availability to the fuel pump, and the was no CEL or error codes or anything like that. Glad I got the car to the shop without needing a tow, but no ideas what caused this.
It could be a number of things; fuel pump, crank sensor, contaminated fuel, etc.
Update: Spoke with my mechanic and it looks like the AOS failed and the car puked oil into the cylinder, fouling the plugs. Will have to replace the spark plugs and the Air Oil Separator. This is the 4th AOS for this car (car has ~105K miles on it), the 3rd that I have had installed on it. This current one was put in earlier this year, around February, meaning that the part is under warranty, but I am still going to be out for the labor costs. The car has had fewer than 5K miles since it was put in, and I have always been careful to keep the oil at the optimal level (i.e. not too high). Car has never been tracked. I have heard that these stock AOS's are a weak link, but this is getting a touch ridiculous.
The AOS in these cars is somewhat weak, but that's an extremely short life. You might want to talk to the shop that put in the one in February. I would hope they stand behind their work (even the labor) for at least 12 months, especially since the car is not tracked.
