Sure fire way to test glow plugs

[burn_your_money]

I borrowed a infrared thermometer from work to test my glow plugs. The original temperature of the plugs was -24 to -26F. I cycled the plugs once and they all got up to -9F except for one, it only reached -16F.
The plugs were installed in my engine so is it possible that the one that only reached -16 may be a different brand and doesn't transfer as much heat from the tip to the exterior? Should I be concerned and replace it?
I'm going to say this is the easiest way to test plugs, it only took 3 minutes and all I had to do was stand out in the cold and pop the hood

[745 turbogreasel]

It doesn't get as cold here, and mine only show a change of 5 or 6 degreesF
when they are good.
i'm of the opinion they work or they don't,  but I've been wrong before.
I guess living in - degrees country, glow function is more important too.

[hipifreq]

Hmm... don't know about the temp change. Which cylinder was different? Perhaps it has more to do with what's around the plug, including piston position at the time.

I've been having rough start issues lately, and when I checked my plugs with the resistance check I had one that was dead. It had infinite resistance. Oddly though, all the rest read a resistance of zero instead of the 1.5 ohms I've read elsewhere (but isn't in the Bentley).

Wish I had an ammeter that read high enough to checks the amps being pulled. My multimeter is a cheap piece-o-.... that only goes to 0.5 amps. Don't know if the amp method would find one that isn't quite working to full function.

[jtanguay]

sure fire way... i recently had my injectors changed... cycled glowplugs and voila they all glowed.  of course this isn't a 10 minute job...  :roll:

[Doug]

My 85 Jetta has a cheap 60 amp ammeter in series with the glow bus under the hood. A quick peek while on glow cycle tells whether or not they are all working more or less to design. Of course the ultimate would be to have the ammeter inside but that would require some cabling to be pulled through.

[burn_your_money]

2 of the pistons are always in the same position so I don't think that was the issue. It was the 3rd cylinder that had the low reading.

[hipifreq]

My 85 Jetta has a cheap 60 amp ammeter in series with the glow bus under the hood. A quick peek while on glow cycle tells whether or not they are all working more or less to design. Of course the ultimate would be to have the ammeter inside but that would require some cabling to be pulled through.

Can you point out a source for that "cheap" ammeter? All I've been able to find is multimeter types that are $100+.

[745 turbogreasel]

get the stock one out of an old (pre 88) Chevy truck at the salvage yard.
Some are 60A, the others 30A

[commuter boy]

sure fire way... i recently had my injectors changed... cycled glowplugs and voila they all glowed.  of course this isn't a 10 minute job...  :roll:

Get the right angled Hazmet wrench for the injector lines and it isn't too far off that.  That thing was well worth the $30.

[Doug]

Go to any auto wholesaler or clearance place like Canadian Tire, Princess Auto or in the States, Pep Boys. They all carry guages designed to be panel mounted for under $20.