- Joined
- Feb 4, 2022
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First off, this is a friend of mine. He's posted over on the Facebook groups, but is trying to get alternative ideas. Here's what is going on:
74’ pa-28-180 owner here. I posted a few days ago about a partial power loss I experienced after takeoff a few days ago, and I chalked it up to carb icing. Well, yesterday I took the plane back up in clear sunny conditions and the exact same thing happened again. 500 feet AGL after takeoff, rpms slid down to about 1800 and the yokes began to shake pretty bad. Turned around and landed on the other runway, then brought it over to the on-field a&p’s hangar. He removed the bottom spark plug on cylinder 4 and it looked like there was some carbon buildup, so he replaced the plug and had me try again. Went to the runup, mag check was flawless, taxi’d around for a bit and the engine ran smooth, so I went for another takeoff. This time, 200 feet AGL, the rpm drops down to a little over a thousand and the yoke shakes even worse. Was able to get it down safely and taxi’d back over to the hangar. I just bought this plane; and am having these troubles trying to get it out of the airport I bought it from. The previous owner only flew it 25 hours over the past 2 years, but the compressions were all 77+/80 on the pre-buy. The a&p checked cylinder #4 compression and now instead of it being 77, it was down to 60. He said he could also hear it leaking out of the exhaust. He wants to send cylinder #4 out for overhaul, and is assuming what is going on is a sticky exhaust valve. The issue here is that the engine runs flawlessly on the ground. I can hold the rpms at 2500 in the runup for minutes and it will not skip a beat. The only time this issue presents itself is when the wheels are off the ground. The fuel pump is on, and making a good sound as well as showing good psi. The tanks are full and the fuel is sumped. I’ve tried contacting multiple other a&p’s and even the lycoming factory and nobody has an idea to what the issue might be. I am being told that a sticky exhaust valve will usually consist of the engine not running well on the ground as well, which means that it’s most likely NOT my issue. Very confused and frustrated, so this may be a shot in the dark but if anyone has had this happen or has any idea as to what it may be, please let me know. Thanks.
Anybody experience anything like this before? Your ideas and help is much appreciated. Thank you!
74’ pa-28-180 owner here. I posted a few days ago about a partial power loss I experienced after takeoff a few days ago, and I chalked it up to carb icing. Well, yesterday I took the plane back up in clear sunny conditions and the exact same thing happened again. 500 feet AGL after takeoff, rpms slid down to about 1800 and the yokes began to shake pretty bad. Turned around and landed on the other runway, then brought it over to the on-field a&p’s hangar. He removed the bottom spark plug on cylinder 4 and it looked like there was some carbon buildup, so he replaced the plug and had me try again. Went to the runup, mag check was flawless, taxi’d around for a bit and the engine ran smooth, so I went for another takeoff. This time, 200 feet AGL, the rpm drops down to a little over a thousand and the yoke shakes even worse. Was able to get it down safely and taxi’d back over to the hangar. I just bought this plane; and am having these troubles trying to get it out of the airport I bought it from. The previous owner only flew it 25 hours over the past 2 years, but the compressions were all 77+/80 on the pre-buy. The a&p checked cylinder #4 compression and now instead of it being 77, it was down to 60. He said he could also hear it leaking out of the exhaust. He wants to send cylinder #4 out for overhaul, and is assuming what is going on is a sticky exhaust valve. The issue here is that the engine runs flawlessly on the ground. I can hold the rpms at 2500 in the runup for minutes and it will not skip a beat. The only time this issue presents itself is when the wheels are off the ground. The fuel pump is on, and making a good sound as well as showing good psi. The tanks are full and the fuel is sumped. I’ve tried contacting multiple other a&p’s and even the lycoming factory and nobody has an idea to what the issue might be. I am being told that a sticky exhaust valve will usually consist of the engine not running well on the ground as well, which means that it’s most likely NOT my issue. Very confused and frustrated, so this may be a shot in the dark but if anyone has had this happen or has any idea as to what it may be, please let me know. Thanks.
Anybody experience anything like this before? Your ideas and help is much appreciated. Thank you!
