I had a hard time starting my truck last winter any time it got below 20 degrees if I didn't have it plugged in. The batteries are the originals, had them tested and were still good. Thinking about new glow plugs, I've never taken them out, need some advice on how to go about it. I see there are glow plug reamers, is one of these recommended or is it not needed. Any other thoughts about what might be the problem would be great. Thanks in advance.
Changing glowplugs, 03 7.3 ford
- Thread starter truthrider
- Start date
from what i've seen usually the first and easiest thing to try on the 7.3 is to change out the glowplug relay, if you haven't already. i cant remember exactly(been a while since we had a ford in the barn) but i think its by the filter housing but not sure. its much cheaper and easier to try than changing the plugs and i believe it was a pretty common issue for bad starting on the 7.3.
the glow plugs themself i'm pretty sure are under the valvecover and are pretty much like changing out a sparkplug but they are known to seize in there pretty good and can break off so ya gotta be carefull. thats about all i know and i'm not positive if its all 100% correct so maybe some ford guys can chime in with anything else.
the glow plugs themself i'm pretty sure are under the valvecover and are pretty much like changing out a sparkplug but they are known to seize in there pretty good and can break off so ya gotta be carefull. thats about all i know and i'm not positive if its all 100% correct so maybe some ford guys can chime in with anything else.
Glow plugs are not that uncommon. Using a test light cycle the key and make sure you have juice on the "cold" side of the glow plug relay when the key is turned on. If you do then it more than likely needs glow plugs.
Drain the coolant, remove the coolant tank, and the belt. There are two accessory brackets on the front of the motor that get unbolted and rolled forward to access the front valve cover bolts. the A/c pump can be rolled over and layed by the passenger fender. Remove the charge air cooler pipes. Unplug the engine harness on the drivers side valve cover and remove the bracket this should open up the valve covers for removal.
Mine wasn't an 03. But is was a powerstroke, you will need a deep well 10mm socket (1/4 drive). The glow plugs are between the valves down in the head. You will see a wire going down in that area. The wire just pulls off with a pair of needle nose pliers. They don't actually seize in the head, it is the end of the glow plug that can enlarge when they go bad and can stick in the head when you unscrew them. I never had a problem getting one out. I will agree with everyone though, it is more common for the relay to quit. I solved that by just replacing it every year. Sometimes the connections at the valve cover gasket get bad too. If you need new connections try Navistar rather than Ford. Ford will try to sell you a complete harness.
T
theultrarider
Well-known member
I changed out the glow plugs in my 7.3 at about 200,000 last fall just to be good to it. Now with that said, I have HAD to change out the relay almost once a year since it was new in 96! You may have an issue with a bad plug or two, but it would still start, just idle rough til warm generally. If you are having a hard start or no start issue, I will bet that it is the relay and not the plugs themselves. Bonus is the relay is much cheaper and easier to change.
I have 4 brand new glow plugs for the 7.3L motor. If you want them send me a PM and I will send them to you if you pay for the freight. I had a 2002 7.3L and bought 8 of them and only changed 4.
I have had the 7.3 not start or start hard with a few bad glow plugs below 40deg . Agreed the relays are common, but have changed alot of 7.3 glow plugs. Have also run across a few wiring problems( bad or broken wire from ECM to glow plug relay) ground wire that activates GPR is controled by the ecm. There is also a way to see how many glow plugs you have bad and which side they are on. You need an Inductive amp probe. The output wires off the GPR break off to each valve cover, isolate each wire, check with the amp probe should have apprx 40amps per side 10 amps per glow plug. hope this helps.
