sanadrustom

Hey guys

Hope all is well. Lately I have been noticing a hissing sound when I accelerate. It almost sounds like a vacuum leak sound but more when it's sucking air if that makes sense:s. I dunno if this is causing a miss fire/hesitation when accelerating. Also I have two codes p0175 bank 2 running rich and p0172 bank 1 running rich. Would those cause the miss fire hesitation or what you guys think?

Thanks

Kneale Brownson

Take off the triangular front engine cover and examine the hoses on the diverter valves.

PaperToast

+1, and also check all the hoses going to and from the intercoolers, one of those might have popped off

sanadrustom

Thanks guys

I checked all the dv hoses seems to be okay no visible leaks. I'm still hearing the hiss this weekend it's due for an oil change so I'll check hoses under the engine coming off the turbos hopefully I can fine something. Do you think it might be something to do with a vacuum leak?

Thanks

Kneale Brownson

Did you take off and check the flexible Y hose? They are subject to tearing under the clamp. That's not something you find by looking at it.

sanadrustom

You mean the one on the throttle body?

Kneale Brownson

Yes, the throttle body Y hose. Tears under the clamps.

sanadrustom

Thanks I'll take it apart this weekend and see what I can find. This could be related or it may not but I noticed today a semi strong gas smell. I'm not sure I smelt it before but def did smell it this morning

Thanks again

sanadrustom

I have yet to check the Y hose (busy with moving) but that being said I noticed lately that it's louder hiss when the car is cold. I still hear it when warm but def more noticeable when cold if that helps at all:s

Thanks

John535is

There is a booster pump at the back of the 2.7 right side in the V section. This pump is only used when the engine starts from cold. Mine used to make a 'whine' rather than hissing due to the bearing was going. I only mention it from your post that it is more noticeable when you first turn the engine on. The pump pulls some decent current so there is a large power plug next the the pump. You could try just unplugging the pump to see if the noise goes away. The pump is about 5' round at the rear of the V near the fire wall. They are expensive ($250) so don't go replacing it unnecessarily.