Glow plug help please

[92EcoDiesel Jetta]

I think he means IR laser; those can measure temperature w/ the right equipment.

Nice Duraterm graph.  Didn't know that's how they worked.

IR thermometer? Never heard it called an IR laser. The laser is used for aiming, not for temperature measurement. IR thermometers are known to be inaccurate against light colored objects (such as raw aluminum or a hot glow plug tip) and more accurate on black objects.

[745 turbogreasel]

Nice theory, but duraterms don't glow that bright.
Even if it were out of spec at 3%, I'd still show 997 instead of 1000.  If you point it at a light bulb, it  is a bit funny aobut  how many layers of glass it's going through.
They are probably  graphing the calculated temp of the nichrome?  wire inside the casing.
You can easily see that the tip of the duraterm plug is not as hot as the  regular one.

The inconel shell would be malleable if it were getting that hot

Heat Treatment       The alloy is not hardened or strengthened by heat treatment.
Forging       Forging should be done in the temperature range of 2250 F to 1900 F.
Hot Working       Hot work in the range of 2250 F to 1600 F. Avoid working in the range of 1400 F to 1000 F as the alloy is apt to thermal crack in that region.
Cold Working       Cold forming may be done using standard tooling although plain carbon tool steels are not recommended for forming as they tend to produce galling. Soft die materials (bronze, zinc alloys, etc.) minimize galling and produce good finishes, but die life is somewhat short. For long production runs the alloy tool steels ( D-2, D-3) and high-speed steels (T-1, M-2, M-10) give good results especially if hard chromium plated to reduce galling. Tooling should be such as to allow for liberal clearances and radii. Heavy duty lubricants should be used to minimize galling in all forming operations. Bending of sheet or plate through 180 degrees is generally limited to a bend radius of 1 T for material up to 1/8" thick and 2 T for material thicker than 1/8".
Annealing       Annealing following cold working may be necessary. The annealing temperature is 2100 F and the alloy should be rapidly cooled through the range of 1400 to 1000 F to avoid thermal cracking.

[92EcoDiesel Jetta]

If you want to measure glow plug temp, don't use an IR thermometer. A type K thermal-couple will be a lot more accurate.

[wolf_walker]

I've had good luck with duraterms as well so far.  I too can remember hillfolk's experience with them back years ago.  It was clockwork to replace one at least every season.
I seem to get two years or so out of a set of duraterms at least, but that's just a so-so guess still.

I'm very surprised to hear you are only getting 2 years from Duraterms, especially in CA!!  I've had the same glow plugs in Jezzie for 5 years now, and they weren't new when I bought her either.  They all work perfectly fine...

There are a few things that can cause glow plugs to die early:

- using 'fast' non-duraterm plugs with a 'slow' relay
- having a defective relay that is keeping the plugs on way more often than they should be
- overtightening the plugs on installation
- bad injector spray

Duraterms take care of the first two points as they are self-protecting.  If you are eating plugs that fast then I'd check out your installation procedure and your injectors - there really is no reason for them to be failing that quickly.

It's just a guess, and I've only been in CA since June.  When I say "set" I mean one of the four I bought and installed died, so I replace them all.  
I lost a duraterm after one season on the last set I put in the 81 back east, and I can think of at least one more that's died.
Course it is the original GP relay with 600K and change on it, with the stock wiring, and it's worked fine since 84 or so when Pop bought the thing in Oklahoma.
So it might be getting a little worn.  I'll never know, left it to a friend back east when I moved like a dumbass.  Overall I'd call the glowplug system troublefree
to be honest, I've never had much grief out of em.  Coldest place I've spent many winters was Oklahoma, but still.  Replace GP's in the fall if one dies.
It takes twenty minutes and cost less than a lot of less healthy things.  I can't remember what's in the 82 now.

[745 turbogreasel]

If you want to measure glow plug temp, don't use an IR thermometer. A type K thermal-couple will be a lot more accurate.

I already did, and have no further interest in doing so.  Out of curiosity, how do you propose to attach the K-probe, and which part of the glow plug will you atatch it to?

The needle on  my K type gauge is  wider than the discrepancy between the readings at 1200F.

[92EcoDiesel Jetta]

[quote author=745 turbogreasel,  ............  Out of curiosity, how do you propose to attach the K-probe, and which part of the glow plug will you atatch it to?

The needle on  my K type gauge is  wider than the discrepancy between the readings at 1200F.

[/quote]

By contact, to the tip of the glow plug. I have a low mass type  k probe for my dvm. I estimate it is accurate to +/- 5 F.

[745 turbogreasel]

Measuring at the tip may fool you, as the  old style heats the tip much hotter than the duraterm which may actually put out more heat by heating evenly all the way to the root.

[millertime]

Ive been running diesel rx glow plugs since i found out about them for my 7.3 pos ford.  All I can say is they are amazing.  American made and there supposed to be able to constantly glow.  I've been running them on my 7.3 for a couple years with a manual push button and i just recently put them on my 1.6td during the engine swap.  You can get them on ebay.  I just wish they would make them for my 2.2 perkins ranger, those things are 40 dollars a plug and they suck. 

[hillfolk'r]

DUDE get me one of those Perkins flame thrower glow plug intake thingeees i always wanted to see one in open air.  Ah the ol Gerkins engines.  I messed around with a few mainly the 4.236s but those r common