Heater in Pa 28-180
Ok, I have a 1974 Archer that suddenly has an oily smell coming out of the heater system with a CO2 level with a highest level of 69ppm coming mostly out of the defroster vents but is not measurable in the cockpit in general, possibly due to diffusion of whatever is causing the odor. The main heater hose from the muff had a few very small,holes in it so I Replaced it. No change. If I close the heater vent it goes away and I can cut the CO2 level to 7ppm if I close the heater valve half way. No, I am not out flying it around like that but went out with a buddy for a bit to try to troubleshoot it.mI pulled the cowling and looked for any other hole in hoses and removed the and checked for cracks in that part of the exhaust but saw nothing. There is a little oil coming out of an area of the engine, very small, but enough to leave a light coating of oil on a few places . I will addres s that shortly I cleaned all of that up, started it and let it run a few minutes and the levels are still there. It's such a simple system I can't believe I don't see a leak anywhere. Any ideas?