The-sky-captain Posted November 8, 2014 Report Posted November 8, 2014 I flew from Arkansas to Colorado today for the opening day of snowboard season. Over 4 hours of smooth flight with a big headwind. About 10 miles out I felt a small, steady vibration and a faint smokey smell. A short while later my number 4 egt spiked from 340 to 490 in a very short time frame and was flashing. I enriched the mixture and popped the cowl flaps and after about 90 seconds the condition subsided and the remaining 5 or so minutes all looked, felt and smelled normal. The long taxi in was fine and I did a short run up with no issues. My two thoughts are clogged injector or stuck valve. I called my mechanic and he's leaning toward the clogged injector but the smokey smell has me puzzled. Would either instance cause this? Your thoughts?? Quote
Andy95W Posted November 8, 2014 Report Posted November 8, 2014 "Smokey smell". Any chance it smelled like a dead bird? Definitely pull the top cowling and take a look. #4 is at the back so if you did ingest anything into the cowling it would go toward the back, could block airflow, and could spike your CHT (I assume you meant CHT and not EGT). After that... Clogged fuel injector, which then cleared itself, but should probably still be cleaned. Just an educated guess and $ .02 worth. Quote
The-sky-captain Posted November 8, 2014 Author Report Posted November 8, 2014 I did pull the cowl and all looks ok. No birds or other riff raff. 1 Quote
The-sky-captain Posted November 8, 2014 Author Report Posted November 8, 2014 Yes CHT is what I meant... Quote
moodychief Posted November 8, 2014 Report Posted November 8, 2014 Bodie, Did you by chance get the munchies after you smelled the smoke??? Quote
MB65E Posted November 8, 2014 Report Posted November 8, 2014 I know at certain temps I have smelled things.... I usually pick up on the vibration first. Engine monitors rock!! I'd pull the injector and spark plug to see how lean things actually were. 490 is close enough to 500 to worry about it. Good luck, I'd get it checked out... If your a close to grand junction, I'll vouch for west star there! Fly safe, -Matt Quote
moodychief Posted November 8, 2014 Report Posted November 8, 2014 Bodie, Just to make sure, you may want to check around your muffler. I had a similar situation and couldn't find anything. I removed my side cowling and saw some discoloration on the muffler shroud. The weld on the muffler developed pin holes and chunks of the weld were missing. This in turn burned some of the cabin heat scat tubing and a strong smokey smell filled the cabin momentarily. I ended up having the muffler rebuilt (only had 250 hrs since last rebuild) and replaced scat tubing. Quote
Piloto Posted November 8, 2014 Report Posted November 8, 2014 A defective spark plug or its cable can cause the sudden rise in temp. Check the cable by slightly pulling on it Check also the cable routing for both plugs. If it happens again switch magnetos.  José Quote
kmyfm20s Posted November 8, 2014 Report Posted November 8, 2014 Look around the exhaust flange for a possible leak. You could be blasting your CHT probe with hot exhaust gases and burning a few things at the same time. Quote
The-sky-captain Posted November 8, 2014 Author Report Posted November 8, 2014 I wonder why it was so short lived? Clogged injector seems to lean toward that. On ground the engine compartment didn't have a burnt smell. I only pulled the top cowl but all looked good from the top. Quote
Guest Posted November 8, 2014 Report Posted November 8, 2014 Bodie, Did you by chance get the munchies after you smelled the smoke??? Isn't that a recently legalized hobby in Colorado? Clarence Quote
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