We recently got our mini repaired and it was running like a scalded dog but developed a partial erratic idle later the same day but still ran fine at least until this past Monday despite. Last night I noticed it was ******* like it was in limp mode but no CEL. I looked things over last night after I got home and figured out the source of the idle issue had been the pcv tube on the rear of the valve cover came loose, so that's fixed but still power is like limp mode with no CEL. The repairs were replace valve cover, spark plugs, coilpack on no 1, waterpump, heat transfer line and thermo housing.

 

Hook up your scanner, see what comes back sometimes there are pending codes that wont trip the light.

 

Well an update, I took the car to the shop a week ago and apparently they are having a hard time even diagnosing the problem. I had used my bluetooth scanner before I took it in that just showed misfires in all four cylinders. I then pulled the neg cable to clear those before taking the car there but car continued to have the issue. Their scanner isn't seeing any codes. It's got to be something electrical connected to the closed loop operating system because the car runs good up to going into closed loop but that should se
an error code I would think.

 

If one cylinder misfires it will lead to a misfire on all of them if its a coil pack... least thats what i experienced when my coil went (2 separate times 2 different coils). I found it by clearing the codes (which you dont have) and then using a live scan when i turned on the car... but if your not getting a fire on a cylinder you will know... car will be loud and lurch around and feel like your down to 10hp. (meaning you can accelerate down hill and maintain on flats... but up hills is a problem). Other then that might be a vaccum line, check the pvc line coming out the of the valve cover, depending on age and climate, may have a hairline crack. (I replaced mine with a piece of black thick walled hose pipe... (cant remember what it was actually called 40min job)

 

I took the pvc tube out and added blanking caps a week or so after getting it back from the shop the first go around, they said they had found a leak in it and did some patch work to it. That was causing a lurch at idle due to it coming loose where it connects to the valve cover. Everything was the same before the caps only there was a cel due to the pcv leak.

 

Okay. After a week at the shop it was determined that my oil catch can was full and not allowing pcv system to work at 100%. Car is running normal again. So if anyone has these symptoms at some point and you recently installed an oil catch can there was some advice 😉👍