How do I check my Glowplugs to see if they are working?? Car won't start in cold

[mtnbob]

I pimped my glowplugs(Thanks to Vince!!!) They worked great last year, but now I'm not starting on cold mornings. The fuses are all still intact, the relay is still working(I can hear it) I'm getting tons of white smoke, so I have fuel. How do I check the individual glow plugs? I'm assuming I'm not getting any to fire up, since I'm not starting.
Thanks
Robert

[mtnbob]

Ok I have a little over 12 volts at the battery, and 11.2 volts at the glow plugs when they are activated. So I'm getting power to the glow plugs. Is there any way to tell if the glow plugs are working? Would they be warm to the touch from the engine side? Do I have to take the out to check them?

[Vincent Waldon]

Since you had the forethought to pimp your glowplugs testing them individually is a snap: 

-pull the 4 fuses to isolate the plugs from each other
-using a test light or multimeter, check for continuity between each plug and ground.  If using a test light for example, one wire of the light goes to the positive post of the battery and the other is touched to each glow plug in turn... you can do this right at the fuse holder if that's easier.

[mtnbob]

Sorry to be an electrical dummy, but how might I do that with a multi tester? I don't have a test light

[rabbitman]

Sorry to be an electrical dummy, but how might I do that with a multi tester? I don't have a test light

Put it on the 'beep' setting and see if there's continuity between the GP and ground.

This test isn't perfect though, I had one that showed continuity but when I took it out it wouldn't glow

Another method that I haven't tried is to glow the plugs a couple times and then feel if they're hot.

It's almost for sure one or more bad plugs, if you have lowish compression then you'll need all four in cold weather. Does it fire at all?

[Vincent Waldon]

Sorry to be an electrical dummy, but how might I do that with a multi tester? I don't have a test light

Rabbitman's got it.

If your multimeter doesn't have a "beep" setting set it to "Resistance" or "Ohms".  Find a good ground for one lead, and touch the other lead to each plug in turn... you'll looking for a very low resistance (an ohm or two)... when they burn out they'll read to infinity.. and beyond. 

[mtnbob]

I ended up taking them out and checking them. Only one good one out of four Replaced with some used ones that I checked before I reinstalled. Any suggestions on new ones?? Not sure the brand of what was in there, but they were made in France. They have autolite locally for $10 each. Is there a better brand I should look for?

[maxfax]

Stay away from Autolite and Champion glow plugs... They are cheap, the are easily found, they suck!!!  I've had both of those brands in both VW and mercedes..   THey've done anythin g from just plain burn out prematurly, to the ends blowing off, and the real head scratcher ---  THey would glow reddish, but not get hot enough to do the job (Tested fine, felt warm when cycled, then I pulled them out to test them )..     Bosch, specifically the Duratherms are the way to go..   Beru and NGK would be second runners up.. I'd still go for the bosch, the cost isn;t that much different, and they work and last so much better than the rest...

[mtnbob]

I bought 4 Bosch from Autohaus AZ

[homerj1]

I just removed the bus bar from the 2 back  glow plugs (closet to trans) and then touched a  wire to each plug and the battery (individually) and looked for a spark. No spark = bad glow plug. Then I ran the same wire to the bus bar (which was connected to the remaining two glow plugs (front hard to reach ones) and looked for a plug that was "twice as big". I found it easy and quick - and therefore had more time for the consumption of yeast-based beverages. 

Aivars