Coolant smell

[rwh]

I am experiencing a coolant smell after flight. Thought maybe it was do to completing the SB for the radiator as there was some spillage. Now, after 20 hours or so on the engine it still exists. There are no signs of any kind of fluid leak.

 

[jrtens]

Check underneath the expansion tank. Any fluid from a service spill or a small leak in the sight gauge or cap would collect on top of the rubber heat shield and then drop down on the engine - leaving an orange residue.

 

[jrtens]

Also check your engine SN to see if it is affected by Rotax SB 912-015iS for faulty expansion tanks.

 

[DHeal]

Also check all coolant hose connections for leaks and clamp tightness. It is not unusual for clamps to need a touch of tightening or repositioning a few hours after replacement.

 

[rwh]

I have searched multiple times for any leaks. There are none to be found. The aircraft had an expansion tank inspection. When I had the inspection done there was a comment on the amount of fluid in the overflow tank as it was about half way between full and min. The shop said they only like to fill to min. I do notice that the expansion tank is always full to the top, but no sign of any overflow there.

 

[jrtens]

The only other thing I can think of is that some spilled coolant might have gotten into the heat muff?

 

[bbaggerman]

I have searched multiple times for any leaks. There are none to be found. The aircraft had an expansion tank inspection. When I had the inspection done there was a comment on the amount of fluid in the overflow tank as it was about half way between full and min. The shop said they only like to fill to min. I do notice that the expansion tank is always full to the top, but no sign of any overflow there.

Have you looked around the water pump under the engine in the back? It is a little hard to get to and inspect.

 

[DHeal]

Some good info here: https://www.rotax-owner.com/en/912-914-technical-questions/9644-coolant-leak_1

Also, there is a small weep hole under the coolant pump that serves as a vent for the water pump's oil and water seals. ROTAX says that a very small occasional bit of water or oil seepage may weep through this hole and it is normal. See Paragraph 1.5 "NOTE" at: https://legacy.rotaxowner.com/si_tb_info/serviceinfo/si912001.pdf

 

[Tony Kirk]

I have searched multiple times for any leaks. There are none to be found. The aircraft had an expansion tank inspection. When I had the inspection done there was a comment on the amount of fluid in the overflow tank as it was about half way between full and min. The shop said they only like to fill to min. I do notice that the expansion tank is always full to the top, but no sign of any overflow there.

Did you ever find the source of the leak/odor?

 

[rwh]

I never found a leak. The smell seems to be subsiding.