How often do you replace your Nitro Engine Glow Plugs?

[gandalfnz]

I was quite proud of myself that in my prob 5 year nitro career, I have never replaced a single Glow Plug.
Until today...
I have been having issues tuning some of my nitros, and could not figure out why some were just impossible to get running right.
Stripped down and cleaned carbs over and over again, to no avail.
Now, its worth saying that, I always do check that plug is glowing bright every now and then.
The plugs I replaced were all glowing fine, which is why I never suspected they could cause issues, however after replacing them, tuning issues went away.
In particular, two of my nitros would run fine at WOT, but would shut down and sound like they are running very very rich once the car is at a stop, often just shutting down completely after few seconds of idling.
Thinking most of the time it was my tuning that was off.

Anyone else experienced where a glow plug looks like its perfectly fine, but engine ran like poop, until you replaced it?

Has anyone got any experience with HSP N4 plugs, that you can buy for $5 on Aliexpress?
I run mostly OS#8 and I know they are excellent, but they are NZD $20 each.

Also, I am not a big fan of just replacing stuff just for the sake off it.


Thanks

 

[tudordewolf]

Has anyone got any experience with HSP N4 plugs, that you can buy for $5 on Aliexpress?
I run mostly OS#8 and I know they are excellent, but they are NZD $20 each.

The problem I run into with HSP plugs is that they physically break. I've never found any reference to this failure mode for glow plugs. The center post would be loose, like I could wiggle it around with my finger, and even twist it and the coil on the other end would wind or unwind. The coil wasn't broken and it even still glowed, but the body of the glow plug was shot, whatever insulator they'd used would crack. Maybe they were too hot, and detonating the fuel?

I've blown 3 in a row on a single tank of fuel, engine would cut out at WOT and I'd discover another busted plug after just a few "pulls." I even tried adding a gasket to the glow plug to reduce compression, to avail.

I was sure I was doing something wrong with my tune, until I put in a #8 and it ran fine since. I've never had a #8 disappoint. OS's slogan of "Tough enough to take the heat" seem vindicated.

They're being counterfeited now though, as mentioned in my other post, so stay wary...

 

[gandalfnz]

The problem I run into with HSP plugs is that they physically break. I've never found any reference to this failure mode for glow plugs. The center post would be loose, like I could wiggle it around with my finger, and even twist it and the coil on the other end would wind or unwind. The coil wasn't broken and it even still glowed, but the body of the glow plug was shot, whatever insulator they'd used would crack. Maybe they were too hot, and detonating the fuel?

I've blown 3 in a row on a single tank of fuel, engine would cut out at WOT and I'd discover another busted plug after just a few "pulls." I even tried adding a gasket to the glow plug to reduce compression, to avail.

I was sure I was doing something wrong with my tune, until I put in a #8 and it ran fine since. I've never had a #8 disappoint. OS's slogan of "Tough enough to take the heat" seem vindicated.

They're being counterfeited now though, as mentioned in my other post, so stay wary...

Thanks for that.
The symptoms of a bad glow plug car vary a lot, for you it seems it ran find at low speed and idle, but at WOT it would completely shut off or give you a lean bog?

For me, two cars would just not idle well at all, but when glow plugs were tested outside of the engine, they were glowing like new.
Go figure.

Shame about HSP plugs, was there many that you found with a center post?

 

[Tunedfrog]

Every couple of years, when I decide to finally take the nitro's out.
The last nitro I ran is sitting in @WickedFog house.

 

[tudordewolf]

They ran fine throughout the RPM range, it's that they'd abruptly experience total failure rather early, in the midst of an otherwise perfectly good run.

I haven't run them in a few months in favor of going all-OS, I'd be willing to give them another shot just because I have them left.

My experience was that about half of them had early breakage issues, which brings the real price up to $10 per working plug and the added frustration of having every other one go bad on its first day.

Maybe I got a bad batch, but I tried to "push" through the issue and had a pile of dead plugs within half an hour.

 

[gandalfnz]

Well,

I have a bag full of used glow plugs, I know some are good, so it will be an interesting testing job.
Actually, in sayin that, they all glow well, but why they dont run well in a car, beats me.
I have a chance to buy cheap traxxas glow plugs at $5 each, might take the risk.

 

[Basher_around_town]

Well,

I have a bag full of used glow plugs, I know some are good, so it will be an interesting testing job.
Actually, in sayin that, they all glow well, but why they dont run well in a car, beats me.
I have a chance to buy cheap traxxas glow plugs at $5 each, might take the risk.

I get Traxxas glow plugs are pricey since I own a T-Maxx but don't get used ones, they are probably already damaged from wear and just a scam, always get new and fresh glowplugs from a good climate-controlled hobby store, that is where I find my glow plugs to run the best and last the longest with good idle and power delivery.

 

[gandalfnz]

Just and update on this, turns out it wasn't the glow plug.
The car just still shuts down, so I have upped the idle.
Weird, this engine is always given me issues.

 

[johnnydmd]

I only replace them if they've gone bad, some I have had for years.

 

[gandalfnz]

I only replace them if they've gone bad, some I have had for years

Same, I am back to my record of not replacing a single plug in 5 years of running nitro.
I discovered plug was not the issues.

 

[Basher_around_town]

nitro engines are sometimes a weird journey