Help! Bad smell when I open the cabin heat valve

[rblauson]

Guys this is written also in the General Forum in case there are Mooney drivers that read one and not the other.

So I write you seeking advice. My airplane just came out of annual. I know the mechanic that worked on it. Solid guy, good skills, Mooney experience. I think my problem is connected with this story. He notices an elbow joint valve with bad threads connected to my oil cooler. He replaces it during annual. I test fly the bird and complain about a bad smell I did not smell before annual as soon as I open the heat push pull knob. He removes the cowling and there is a fair amount of oil around the oil cooler area but not on the other side near the muffler/shroud etc. He replaces the elbow joint and suspects a crack in the oil cooler. Thats gets replaced too. Then I ask him to remove all the excess oil around the engine, he rewashes the engine.He removes the muffler and cleans it, he replaces the scat tubing that leads into the airplane with new stuff. Off I go to fly and this time its a different smell, almost sour, hard to explain but smells like residual oil. Can anyone offer suggestions as to what they think might be causing this now? I dont know what he used to clean up the muffler. That might explain it except the smell was different once he replaced the oil cooler and re washed the engine and replaced the scat tubing. It really smells, I do not think the smell is deminishing either. I have flown a few short flights since this and the smell might be getting a little less strong but in no way is it gone. Should I have him reclean the muffler or anything to do with it that might be the culprit? Is cleaning the muffler shroud even possible if oil had gotten into, or on it? I am very weak in this area and Im not sure what to ask him to do. He seems willing to assist but unsure where the smell is eminatiing from. Thank you for any advice on the matter.

Cheers,

Mark

N201SL