You guys aint gonna believe this. I have had my 3.1 sittin' for a week due to a possible leak somewhere. I did'nt want to drive it due to that I might cause more damage until the leak was found. Today I sandblasted the digital EGR pintles and got them nice and clean and I also shot some sand up in the solenoids where the pintle go into the EGR. OK, everything nice, clean and no residue of sand whatsoever. I put the egr valve back on, and it idled good...still heard the leak though.OK, time to run her on ramps to get a looksee underneath. Could'nt see anything wrong at all. BUT HERE IS HOW I FOUND THE LEAK!! Completely by chance and a what-the-heck attitude I turned the pulley on the 4 months now disengaged smog pump. THE LEAK SOUND VARIED. So I turned it to a sweet spot and the leak sound disappeared! Go figure. So here is my question. The serpentine belt has been routed to keep the smog pump outta the loop. After the belt comes off the steering pump, it goes OVER top the water pump THEN under the cam THEN to the alternator. Why can I turn the smog pump to vary the leaking sound? Is there a part I can take off, plug up, or what. Diverter valve maybe? Chime in guys. I need to figure this out. It might help later on with some other peoples exact problem. Talk about a ghost in the machine.

Ken

 

The check valve in the line is bad. You should never have exhaust coming back through the pump. Since you have already basically deleted the smog pump, just rip it off from the check valve back and cover the end with a bolt.

Or cut it off on the exhaust side of the check valve, crimp it, then have someone weld it shut.