EGT increase

MikeLima

Pre-Flight
Joined
Dec 7, 2015
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Missouri
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MikeLima
1976 C-182 Continental 0-470
Single probe EGT- gauge has no numbers but each line is 25 degree increment

Yesterday partner saw from the outset of his flight egt reading approx 75 degrees higher than normal. If applied carb heat, it would drop and as altitude increased, it dropped. This happened once about 15 hours ago but cleared up and has been as per usual sense and I had suspected egt gauge/probe issue. Today I went down and flew it to get more info. Still reading higher than usual. At cruise power, left mag alone would increase egt 25 degrees and right mag alone jumped it 50-60 degrees. (Based on the incremental lines each being 25 degrees apart)

Talked to mechanic and he said exhaust valve. I suspected mag timing issue or something in that line. I can imagine a slight difference in turns when I pull the prop through but obviously that's subjective and I don't even know if it's the cylinder the probe is on. Input?

If it's exhaust valve, is it likely to be a cylinder replacement? If it's exhaust valve is damage already done and flying it won't kill something else or is flying it gonna burn something up?

Be gentle.

ML
 
Take the usual precautions, then turn the engine over by hand slowly and listen at the exhaust pipes for a difference in sound on the compression stroke of each cylinder. This should tell you if you have a bad or failing exhaust valve. -Skip
 
Operation on one mag typically increases egt reading by about 75. Increase should be the same on either mag. I would check mag timing then do a proper compression check. If there is exhaust valve leakage borescope is next.
 
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