Hi,

I'm test driving my 2003 R53 after changing oil in the supercharger and doing some other maintenance while it was in front end service mode.

The engine has a whistle, the check engine light came on, and the idle fluctuates. I think I have an air leak, but there are a lot of potential candidates.

I tried using an unlit burnzomatic torch to see if I could identify the leak, but it didn't make engine speed up or slow down. No matter where I held it. This has worked on carbureted vehicles for me in the past.

I was thinking about spraying carburetor cleaner on the intercooler boots, throttle body, etc. Does anyone have any other suggestions? I'll try to see what codes the engine is throwing when I get home.

Thanks

 

quick visual list while waiting for codes:
throttle body vacuum hose attached
intercooler boots (especially underneath)
intercooler discharge horn tight to the intake
vacuum lines seated on supercharger intake pipe [brake booster and TMAP sensor]
fuel pressure regulator vacuum line under the supercharger discharge / intercooler intake horn

Other than that and depending on what the codes tell you it might be smoke test time.

 

The code I'm getting is 1242: Pressure sensor, intake manifold before compressor-input too low with trailing throttle.

 

Interesting. Squeal / whistle + 'low input signal' thinking leak in TMAP sensor line / union leak at either end of it. Given symptoms doubt it's electrical but I've never had this issue so perhaps others can weigh in. Would still double check both TMAP and MAP sensor electrical connectors are good and fully seated.

In case this helps, from