dead glow plugs???

[cuz]

Last week I landed on my roof fairly hard, not hard enough to do any visible damage, and immediatelly on landing blew my glow plug. I didn't think anything of it, replaced and only got 30 seconds out of the next plug. I waited a week to go get more plugs and in the meen time i resealed my engine. Today I threw a new glow plug in and only got 30 seconds out of it, the next plug lasted about 10 min then died as well. The truck has a very good trail of blue smoke thru all speeds and runs on average 260. The plugs still look new but do not light, one of the plug elements looks mangled a bit but the other is o.k.
Is it possible i have something under my head damaging the plug, or any other ideas are neaded!!
thanks in advance.

 

[Jeremy]

I bet you have metal in your engine .. Pull the head off and see if you have any pitting on the top of the piston .. You must pull the head.

Keep us posted

 

[cuz]

that sucks.. I'll go pull it now, take a pic and re-post.

 

[cuz]

doesn't appear to be any pitting what do you guy's think?

 

[AllanQ]

Someone with better eyes than I have can tell you if they see pitting, but I think that motor has been run way too lean. A very lean engine will blow plugs like there is no tomorrow.

 

[cuz]

I'm pretty sure I wasn't running to lean, My truck averages 260F, Its always had nice blue smoke out it and it takes 4 seconds to die with the fuel lines pinched off. I did have it over lean once ( the only time the trucks wheelied) but richened it right away and have left it since.
With my last plug before it burnt the truck was bogging off the start and wouldn't smoothen out till higher speeds with tons of blue smoke off the line while it was struggling to get going. The only way to get up to high speeds was to bump the throttle a little at a time, a wot would just stall it out.

 

[Larsenracing]

What motor is that?

Also, if you install the plugs into the head whale the head is off the engine do the plugs stick threw the bottom if so you need to find shorter plugs.

The motor to me looks to lean which could easily make the filament wire to distort however if your temps are only at 260 they should be that distorted after that short of run time.

What was your reasoning for resealing it??

 

[Purenitro]

What kind of plugs/fuel are you running. It doesn't "look" like any pitting but it's hard to tell, it does look like it was a little lean but it hard to tell what's going on. The next time you run it, put some white paper under the stinger after you shut it off and catch some drippings of lube. Let us know what you find/see. It could be the main bearing or rod is going but that should show up in the lube.

 

[cuz]

i wiped the piston head prior to the picture to look for pitting in the surface, there was a layer of oil on the surface before. Its the stock xl 5.9 and i re-sealed it after soap testing and finding alot of bubbles around the backplate and carb neck.
I'll check the depth of the plug but the same plug burnt a full gallon just fine.

 

[Purenitro]

What kind of plug is it, what temp range.

 

[cuz]

its a mcoy mc-59, I'm not sure of its temp range (1.5 volt)
the fuel is traxass top fuel power plus 20%
I'm thinking the broken element from the first plug may have taken out the second plug but i'm not to sure on the 3rd and 4th. My only reasoning I can come up with myself is to lean. (unintentional, I always though by my temps of 260 and blue smoke that I was still rich)

 

[Purenitro]

The 59 is a hot plug, that may be why they are burning up. I would try a Mc 9 and maybe richen the hsn just a bit.

 

[Psychobasher]

The hot plug may be advancing your timing too far and causing detonation. The shockwaves produced would do a fine job of smashing the plug's coil apart. As purenitro said, try a cooler plug.