MINI Cooper Forum banner

1 - 3 of 3 Posts

2 Posts
Discussion Starter #1

I own a 2005 R53 170HP since some month. Right now I had idle issues. At cold start rpm goes up to 1200 then slowely 900-1000. While its running/warming sometimes motor/car starts shaking, rpm goes down, then up to standard value, but only for one time. Usually I warm the car for 2-3 minutes.
For a succesful start/acceleration I have to use higher rpm while realising the clutch or the engine start shaking or shut down.
In cold runs the car also have acceleration issues in neutral tranmission mode. I push gas pedal and instead of accelerating its hesitating, rpm goes down, car almost shuts down. After I gentle push rpm to 2000-2500 it starting to get better.
When motor/coolant warmed up this problem almost gone.
But 3 things, after engine/coolant warmed up well:
1. If I switch to reverse problem starts again, rpm goes down, motor shake/engine almost shuts down if I dont add more gas, then I had to do this again to first gear...
2. I noticed that if I push full acceleration in neutral, rpm goes up well, but it starts with a little delay
3. Wanna do a fast launch, neutral to 1st gear rpm goes up around 4000, wheels starts spinning (tried dsc on/off), but suddenly rpm drops to 2000 while motor or compressor whining, rpm slowely reaches 4000, after that I can switch fast/powerfully to second and third gear at 4000 rpm.

Right now I only have one fault code, P0326, knock sensor. But it is not displayed on the dashboard. As I read forums others have similar problems because of knock sensor.
Just I am wondering, is these symptoms caused by a faulty knock sensor, or the knock sensor detects something thats why its failing.

I use high qual 100+ octane gas only from one petrol station.

car background:

I bought the car with oxyigen sensor fault (dashboard noticed it). But the car went fine, like a dream, lot of power, no power issues. I wanted everything to be fine so I (not me, a mini-mechanic) replaced oil in compressor, changed spark plugs (ngk, dont remember the exact type), engine oil (motul x-clean 5w-40), valve cover gasket, oil/pollen filter.
I ordered an NTK oxygen sensor but it isnt arrived yet.
My memory is not the best but as I remember after these changes performance was still fine.
...Maybe a week passed...
Last owner used the car with performance air filter. I wanted to change it back to stock, so i bought the missing intake parts/pipes/new air filter. If I remember correcty after replacing this to stock the pefromance issues started. Car didnt had power just above 3000 RPM and also this power was not the same as before.
I tried the car without air filter for a short test, but it isnt helped. A tuner checked the engine control unit, but the software was not modified.

Oxygen sensor still not arrived, but till that I replaced the fuel filter, we checked/cleaned MAP sensors, also changed one of them (plastic aged and broke near the screwing holes). Nothing changed.

Oxygen sensor arrived, we changed the fault one (first one, before pre-cat), cleared the fault code, performance came back, no issues with rpm.
Although performance was not as sick as when I bought the car, but maybe I got used to it, or probably the performance filter helped a lot.

So, some runs later I noticed those low rpm/idle issues which i wrote down above.

Other notes:
  • since oil change car ate around 0.9L oil at 2500 km/1533mile, no oil leaking below the car, no smoke. The car/this performance is new to me so after warmed I cant drive like a granny, maybe this also cause oil consuption? Also I think next time I try Castrol Edge 5W-30 maybe? Btw car has 200.000 km in it, so...
  • car's exhaust pipes are always sooty
What do you think? Should I change knock sensor or should I check something else meanwhile?

Thanks for the ideas!!!

ps: sorry for language errors :)

2 Posts
Discussion Starter #3
Spark plugs are 3 month old, ignition coil ends arent rusty, they are clean, cables seems ok, but I dont have any spare any of these to test. But I try to borrow them from someone.

Just noticed some hissing sound around the radiator/supercharger. It continous in idle and when I gently press acceleration. But when I press acc faster and the rpm hesitating issue starts hissing sound stops. Maybe there is some vacuum leak? Next week we replace the radiator and check the vacuum lines.

ps.: I swapped to Shell V-Power Racing fuel and launch problem stopped, car has enough power to spin wheels and it hold rpm, it dont fall back to 2000. Maybe its the fuel or just autumn started and temperature is lower??
1 - 3 of 3 Posts