EdS320

1996 S320 78,000

I have a "loud" whining noise upon first startup of engine then it will stop after short drive time or minute or two. I believe it may be the electric air injection pump as it appears to be coming from it. It seems to be louder now that the weather is warmer.

Any thoughts on this symptom? Could the air injection pump be going out or a valve not working?

Thanks...

EdS320

Solved the problem. EGR & Air Pump whine post...After changing the oil I wiped some grease from an electrical connector at the front of the engine, behind the wiring was plastic vacuum tubing that supplies vacuum to the EGR and Secondary Air Pump nest to the EGR Valve by way of the electric solenoids vacuum valves at the front left of the engine. I had inadvertently broken the BRITTLE vacuum tubing, thus killing the vacuum to the solenoids. I put in a rubber vacuum tube splice to reconnect the line ends.
Air from the Air Pump was not going through the Secondary air pump or EGR thus the whining noise.

*CAREFUL when you work with or around the tan colored vacuum tubing, as it ages it gets VERY BRITTLE and will break at the slightest bend or pressure. The same tubing runs next to the spark plugs and coils under the engine top cover. If it does break on you, you can use small diameter rubber tubing to reconnect the broken ends together.