When are glow plugs shot?
03-16-2009 | 10:25 AM
#1
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When are glow plugs shot?
I'm using low nitro fuel(10%) in my OS LA .40. It kept running rougher the last 3 times I had it out. The glow plug still lights up so I figured that wasn't the problem. I then went to adjust on the carb (wish i hadn't went there). It's back to its original setting. I tried a new glow plug and it came to life! The old plug was an OS A8, the new plug is some generic I got from a friend. The new plug does glow brighter than the OS. My question is, do plugs go bad without burning out the element? I remember reading that if glowed it was good.
03-16-2009 | 10:31 AM
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From: La Vergne,
TN
RE: When are glow plugs shot?
ORIGINAL: bgerth
My question is, do plugs go bad without burning out the element?
My question is, do plugs go bad without burning out the element?
You've just learned the best way to tell if a plug is heading south...engine performance changes.
If you have an engine that's been running well, flying well, reliable, etc...and suddenly, for no apparent reason, just seems to get worse with every flight, don't tweedle needles...change the plug. Even if it "looks" good.
03-16-2009 | 10:33 AM
#3
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RE: When are glow plugs shot?
Yes, they can go bad and still glow. The coils have a plating of platinum on them. If this coating is gone the coil can still glow, but the engine will be difficult to run, or not run at all. If you change out the plug and it runs good with a new plug that's probably your best clue that they plug is bad. Even though it still glows toss the old one, it's no good.
Ken
Ken
03-16-2009 | 01:15 PM
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RE: When are glow plugs shot?
ORIGINAL: RCKen
Yes, they can go bad and still glow. The coils have a plating of platinum on them. If this coating is gone the coil can still glow, but the engine will be difficult to run, or not run at all. If you change out the plug and it runs good with a new plug that's probably your best clue that they plug is bad. Even though it still glows toss the old one, it's no good.
Ken
Yes, they can go bad and still glow. The coils have a plating of platinum on them. If this coating is gone the coil can still glow, but the engine will be difficult to run, or not run at all. If you change out the plug and it runs good with a new plug that's probably your best clue that they plug is bad. Even though it still glows toss the old one, it's no good.
Ken
03-16-2009 | 01:54 PM
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RE: When are glow plugs shot?
Moreso than if you just overrun the runway. Any maneuver that brings the throttle to idle, for instance a hammerhead or stall turn, you bring the throttle to idle just before you perform the hammerhead, then leave it there for a few moments. Also, in a loop, at the top of the loop, we normally go to idle or close to it. Any time the aircraft is actually poing down, we reduce the throttle, sometimes to idle, and a loss of engine at that point can be a problem.
All the reason to practice your emergency procedures.. what to do in case of a dead-stick.... well, land of course, but getting it to a point where you can land safely is the practice part. And, of course, losing an engine is the object of that drill.
Having a good idling engine is a good thing and is all part of the setup and pre-flight. You start it up, then check the idle, then check the transition, then the HS mixture, and so on.
CGr.
All the reason to practice your emergency procedures.. what to do in case of a dead-stick.... well, land of course, but getting it to a point where you can land safely is the practice part. And, of course, losing an engine is the object of that drill.
Having a good idling engine is a good thing and is all part of the setup and pre-flight. You start it up, then check the idle, then check the transition, then the HS mixture, and so on.
CGr.
03-16-2009 | 03:17 PM
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From: La Vergne,
TN
RE: When are glow plugs shot?
ORIGINAL: CGRetired
Any maneuver that brings the throttle to idle, for instance a hammerhead or stall turn,
Any maneuver that brings the throttle to idle, for instance a hammerhead or stall turn,
03-16-2009 | 06:30 PM
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From: Brisbane, AUSTRALIA
RE: When are glow plugs shot?
ORIGINAL: gboulton
I dunno, CGr...many of the guys I fly with consider the left stick to be an on/off switch.
ORIGINAL: CGRetired
Any maneuver that brings the throttle to idle, for instance a hammerhead or stall turn,
Any maneuver that brings the throttle to idle, for instance a hammerhead or stall turn,
. I've grown out of this now and practice throttle management constantly. I found this was absolutly necessary when moving to larger Gas planes.Back to original post - Whenever I suspect or notice a reduction in engine performence the first thing I do before all else is change the plug.
03-16-2009 | 06:50 PM
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RE: When are glow plugs shot?
ORIGINAL: CGRetired
Moreso than if you just overrun the runway. Any maneuver that brings the throttle to idle, for instance a hammerhead or stall turn, you bring the throttle to idle just before you perform the hammerhead, then leave it there for a few moments. Also, in a loop, at the top of the loop, we normally go to idle or close to it. Any time the aircraft is actually poing down, we reduce the throttle, sometimes to idle, and a loss of engine at that point can be a problem.
All the reason to practice your emergency procedures.. what to do in case of a dead-stick.... well, land of course, but getting it to a point where you can land safely is the practice part. And, of course, losing an engine is the object of that drill.
Having a good idling engine is a good thing and is all part of the setup and pre-flight. You start it up, then check the idle, then check the transition, then the HS mixture, and so on.
CGr.
Moreso than if you just overrun the runway. Any maneuver that brings the throttle to idle, for instance a hammerhead or stall turn, you bring the throttle to idle just before you perform the hammerhead, then leave it there for a few moments. Also, in a loop, at the top of the loop, we normally go to idle or close to it. Any time the aircraft is actually poing down, we reduce the throttle, sometimes to idle, and a loss of engine at that point can be a problem.
All the reason to practice your emergency procedures.. what to do in case of a dead-stick.... well, land of course, but getting it to a point where you can land safely is the practice part. And, of course, losing an engine is the object of that drill.
Having a good idling engine is a good thing and is all part of the setup and pre-flight. You start it up, then check the idle, then check the transition, then the HS mixture, and so on.
CGr.
i had a guy at my field yesterday that flew like that, w/ a puny .15 engine but boy did that thing hall butt
funny thing is he put a gallon fuel jug (empty one) in the runway and was going to try to hit it on his landing aproch. he gave up after like 15 tries, since his plane didnt have landing gear he had to restart the motor every time. you shoulda seen his face and everyones reaction when i nailed it first time. aahhh the fun of being in a club.
03-16-2009 | 07:05 PM
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From: La Vergne,
TN
RE: When are glow plugs shot?
ORIGINAL: CGRetired
Yeah, Gordon. We have a few of those too. The only time the engine is idling is when they first start the thing up!!!
Yeah, Gordon. We have a few of those too. The only time the engine is idling is when they first start the thing up!!!
Wow...learn something new ever day.[sm=biggrin.gif]
03-16-2009 | 07:17 PM
#12
RE: When are glow plugs shot?
I'm probably the worst person when it comes to changing a plug. I like to add 4 ounces of castor to my gallons so they have even more oil in them. Great for the engine after awhile of repeated flights the plug can get carbonned up. Once I was flying my first Avistar and the guy next to me who was watching said, "that knocking doesn't sound right". So I landed and checked the plug and it was completely carbonned up. Put a new plug in and all was fine. Even had noticeable more power. We should check our plugs more often.
03-16-2009 | 11:02 PM
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From: Lawrenceburg,
IN
RE: When are glow plugs shot?
Heck, last year I got out new glow plugs fresh out the package, and they were shot. One had a loose post or whatever you call it, and one wouldn't glow. Even when new, they don't always work[>:]
03-16-2009 | 11:43 PM
#16
RE: When are glow plugs shot?
Basically, if you haven't deciphered it out of the discriptions so far, when a plug is starting to go bad, you will notice it at idle first. If you listen closely, a new plug will not drop rpms at idle. It may run good for a while longer, so be ready to swap it out. Running lean will also shorten a glow plug's life because of the extra heat.
