Glow plug testing questions

[1 Patriot-of-many]

If they are bad, would the resistance be high or low or can be either way? Just curious. Of the 6 I tested they were all about 1 ohm which is in range from what I've read.

 

[doghead]

If bad, you will almost always read no resistance(open circuit), no continuity.

 

[BIG_RED]

Power them up using booster cables to a battery for a few seconds and see if they get hot/glow. One clamp around the threads and hex head (not touching the tip) and the other clap on the metal tab. I've got some anomalous readings using the multimeter (plugs giving ok resistance but quickly going "open" when powered up). Worth being sure because unless you do the resistor bypass - if one GP is bad it can wipe out all the others.

 

[1 Patriot-of-many]

Should I just replace them all to be on the safe side? I mean it's not that spendy at $65 or so. Another must do? My wait light seems to be work properly, longer when colder but still hard starting, lots of starter time. I see guys saying their engine just lights right off, mine takes a good 10 seconds or more of cranking.

 

[mistaken1]

Could be glow plugs or quite possibly and air leak in the fuel system. Particularly at the stock filter base.

 

[natem]

For the money, replace them all. It's like spark plugs in a gasser, ya gonna replace one fouled plug.

And if you ever have a 6.2 swallow one ( I have ) believe me glow plugs are inexpensive.

Nate

 

[idM1028]

Should I just replace them all to be on the safe side? I mean it's not that spendy at $65 or so. Another must do? My wait light seems to be work properly, longer when colder but still hard starting, lots of starter time. I see guys saying their engine just lights right off, mine takes a good 10 seconds or more of cranking.

I started using the recommended starting procedure (wait light out, foot on throttle when starting, half or all the way, depending on temperature) for a week or two and it seemed to take longer to start than the old method I was using (wait light out, foot on brake instead of throttle, quick blip of the throttle once its started just to kick it into fast idle) so I just went back to the old method. Not sure if this would help you or not.

 

[Tulsafireman]

I just replaced them all with 60G's. Starts much better. Guessing I had some bad ones and like natem said, why would you replace just the bad ones. Mine were the original ones and I wanted them out before they swelled and I couldnt get them out anyway.

 

[Matt65]

If it has not been mentioned yet, be sure to look into the resistor bypass for supplying power to the GP relay. Still running AC 60Gs.