S70 engine noise resolved

tr_car_nut · Post by **tr_car_nut** » 18 Nov 2012, 15:55

My '99 S70 had the strangest noise coming from the front of the engine that started last week. It sounded like an airplane getting ready to take off. Initially I thought it was a bad bearing on the alternator so I replaced the alternator with one from a salvage car ($20). Still had the noise so I replaced the serpentine tensioner ($30). No luck still screaming. This time I took more of an analytic approach by removing the serpentine belt and running the car. The sound still persisted so I headed to the side of the engine to look closer at the timing belt tensioner but the sound was more towards the front of the engine. As I leaned into the engine compartment the sound grew louder and the hissing made me think there had to be some sort of vacuum leak. I put my hand into the area to the back of the power steering pump and left of the intake manifold to touch the vacuum hose that connects the intake manifold to the PCV system. Sure enough the sound stopped as I touched the rubber elbow. I pulled the elbow off of the hose and the manifold and found a small pinhole in the elbow. So after several hours of searching I finally found where the noise was coming from. I'll be heading off to the dealer tomorrow to get a new elbow (not so cheap).

Post by **rmmagow** » 19 Nov 2012, 10:45

No CEL? I'd a thought at least a P0171 for that.

tr_car_nut · Post by **tr_car_nut** » 21 Nov 2012, 15:05

No CEL and it has been broken for about a week now. It is really blowing some air out of that hose. It sounds like a bad clarinet. I got the elbow at the dealer today along with my new ignition lock ($353 - ouch). I'm going to see if the other end of that hose (flame trap) from the intake manifold is clogged.