Symptoms of a bad glow plug?

[vwdave]

Other than not starting, what are some of the symptoms of a glow plug going bad? Can you visually tell, under a magnifying glass, if they are going bad or are bad? Just some curious questions. Truck dies off at idle some, and then will die if you nail the throttle, but not every time., That got me to ting about the question.

 

[Rolex]

It could very likely be the LSN out of tune.
Start with a new plug to see if the same problem occurs.

 

[bgbdwlf2500]

Yep..try a new plug. Even if they glow they may not be good

 

[Nefster]

Hey there people my problem is, if i pull of the starter plug the engine stalls! any suggestions for the problem? Bad glow plug???

 

[Rolex]

Stalling when you remove the ignitor is usually a sign of the LSN being set too rich.

 

[Extreme RC Mods]

This thread should help cover your problem. Signs that a glow plug may be bad are deformed coils, coils that have a grey appearance instead of shiny silver and also if the engine will start but dies as soon as the ignitor is removed, that usually means it's lost it's effectiveness even if it still looks good. I recommend a MC #59 HOT plug for break-in, but once your done the plug is contaminated from the worn material from the lapping process, they will start to act funny so I recommend throwing them in the trash and starting fresh with an MC #8 plug.

https://www.rcnitrotalk.com/forum/showthread.php?t=105290

 

[Nefster]

Thanks i Will work with it!!

 

[jman214]

So I should lean my lsn? When I checked the plug it got hot but did not glow . So they go thru plugs that much

 

[ninnon]

So I should lean my lsn? When I checked the plug it got hot but did not glow . So they go thru plugs that much

This thread is 3 years old...

 

[cbaker65]

It should glo rediish orange! I've used the same glo plugs going up to 5 years.
So it could simply being fouled up an your engine loading up, its not good to let the engine set an idle
especially if its running rich.

 

[olds97_lss]

It should glow when on your heater. If the sun is out, it's hard to tell. Try putting it in the heater when your home. Could just be a weak heater battery mixed with too rich of a tune. I usually leave my heater on the engine for 10-15 seconds at least after it fires up so I can blip the throttle to get the engine running relatively clean, then I take the heater off and drive around gently until it warms up.