Induced vacuum leak leads to new hissing noise. Normal?
04-22-2019, 07:42 AM
#1
Induced vacuum leak leads to new hissing noise. Normal?
Hi all,
In my attempts to find out whether there is a vacuum leak in the engine causing a rough idle and car behavior like before fixing the previous leak I found myself yesterday pulling the oil level dipstick while the engine was running to make sure it seats properly and on doing so I noticed a hissing noise coming from the bank 2 rear area, like around the SAI pump.
Is this to be expected or is there a leak? I think there has to be a leak but my knowledge is quite limited, so looking for experienced opinion.
Some additional information to put in context:
-That SAI pump is failed with the fan missing some blades and the bits probably in the valve downstream. Can this valve leak a vacuum if stuck open? Code for SAI bank 2 Insufficient Flow is active.
-The other part in the area that I know of would be the purge valve hoses. The valve itself works correctly.
-A home made smoke test showed no leaks. Maybe putting more pressure in would bring a different result.
Basically I'd like to know if this observation is normal or not, to either start looking deeper or just leave it
Here's a video of it: At 00:01 I pull the dipstick and the hissing starts to then stop by 00:07 when the stick goes in; next out again at 00:09 and hissing resumes.
Thanks
In my attempts to find out whether there is a vacuum leak in the engine causing a rough idle and car behavior like before fixing the previous leak I found myself yesterday pulling the oil level dipstick while the engine was running to make sure it seats properly and on doing so I noticed a hissing noise coming from the bank 2 rear area, like around the SAI pump.
Is this to be expected or is there a leak? I think there has to be a leak but my knowledge is quite limited, so looking for experienced opinion.
Some additional information to put in context:
-That SAI pump is failed with the fan missing some blades and the bits probably in the valve downstream. Can this valve leak a vacuum if stuck open? Code for SAI bank 2 Insufficient Flow is active.
-The other part in the area that I know of would be the purge valve hoses. The valve itself works correctly.
-A home made smoke test showed no leaks. Maybe putting more pressure in would bring a different result.
Basically I'd like to know if this observation is normal or not, to either start looking deeper or just leave it
Here's a video of it: At 00:01 I pull the dipstick and the hissing starts to then stop by 00:07 when the stick goes in; next out again at 00:09 and hissing resumes.
Thanks
