Interesting find - hissing noise diagnosed
Interesting find - hissing noise diagnosed
I bought an 06 MCS last month and was hearing hissing from the passenger side of the engine near the fuel tank vent solenoid. After spraying a bottle of soapy water on all the lines, removing/reinstalling the intercooler 4 times, and replacing 2 vacuum lines, I finally located the hissing. The hissing turned out the be the far injector on the passenger side (cyl 1?).
While spraying the vacuum lines I went ahead and sprayed the injectors, since my makeshift stethoscope was indicating on that area. As soon as the soapy water hit the injector the RPM's fluctuated like crazy. The hissing in this case was air being pulled into the cylinder, since there was no bubbling from the soap.
I pulled the fuel rail and found the injector seals were dirty, and the o-ring on the particular injector was cut on the cylinder side.
I cleaned all o-rings and reversed the damaged o-ring and now all is well.
Just figured I'd post it.
While spraying the vacuum lines I went ahead and sprayed the injectors, since my makeshift stethoscope was indicating on that area. As soon as the soapy water hit the injector the RPM's fluctuated like crazy. The hissing in this case was air being pulled into the cylinder, since there was no bubbling from the soap.
I pulled the fuel rail and found the injector seals were dirty, and the o-ring on the particular injector was cut on the cylinder side.
I cleaned all o-rings and reversed the damaged o-ring and now all is well.
Just figured I'd post it.
Last edited by Grip Grip; Jan 10, 2017 at 06:16 AM.
3rd Gear
Joined: Sep 2014
Posts: 272
Likes: 1
I bought an 06 MCS last month and was hearing hissing from the passenger side of the engine near the fuel tank vent solenoid. After spraying a bottle of soapy water on all the lines, removing/reinstalling the intercooler 4 times, and replacing 2 vacuum lines, I finally located the hissing. The hissing turned out the be the far injector on the passenger side (cyl 1?).
While spraying the vacuum lines I went ahead and sprayed the injectors, since my makeshift stethoscope was indicating on that area. As soon as the soapy water hit the injector the RPM's fluctuated like crazy. The hissing in this case was air being pulled into the cylinder, since there was no bubbling from the soap.
I pulled the fuel rail and found the injector seals were dirty, and the o-ring on the particular injector was cut on the cylinder side.
I cleaned all o-rings and reversed the damaged o-ring and now all is well.
Just figured I'd post it.
While spraying the vacuum lines I went ahead and sprayed the injectors, since my makeshift stethoscope was indicating on that area. As soon as the soapy water hit the injector the RPM's fluctuated like crazy. The hissing in this case was air being pulled into the cylinder, since there was no bubbling from the soap.
I pulled the fuel rail and found the injector seals were dirty, and the o-ring on the particular injector was cut on the cylinder side.
I cleaned all o-rings and reversed the damaged o-ring and now all is well.
Just figured I'd post it.
Thanks and you're both welcome. Hopefully this will save the next guy a little time in pinpointing the issue.
