I really appreciate the wealth of information that is shared on this board and I’ve learned a lot, but I don’t post here often because... well, quite frankly, I don’t feel like I have that much to contribute. However, last weekend I replaced my glow plugs and thought I might share some tips for those who might be a little apprehensive about this job like I was.
There aren’t many repairs that I’ll shy away from, but this one had me a bit spooked, what with all the horror stories about stuck plugs and broken tips. But, with the colder weather lately, my truck was becoming harder to start, and my WTS light was only staying on for 6-7 seconds. So, I checked each plug with a test light and found one bad one. I decided to replace the whole set, since after nearly 20 years of service, I figured more might be on the verge of failure.
When my new ZD9’s arrived ($80.08 delivered from RockAuto, btw), I was ready to jump in. Removal of the air cleaner assembly (ATS 093 turbo) makes everything pretty accessible, except for the plug under the turbo (#7). On an N/A engine, access would be a piece of cake. I started with the easy ones (driver’s side). All of them came out without a fuss. Quite frankly, I was surprised at how easy they were to break loose and unscrew. A great tip (I think I read it on this forum, so thanks to whoever posted it) is to use a length of rubber hose pushed over the end of the plug to unscrew it, and to get the new one started in the hole and screwed in. This is much easier than trying reach in there with your fingers, and it basically eliminates the danger of cross threading. When installing the new ones, take note of the torque spec on these (12 in lbs). That’s nothing! Just finger tight with a 1/4 inch ratchet if you don’t have an in/lb torque wrench.
On the passenger’s side, the first two (front to back) were easy. The next one (#5) was a little tricky, but not too bad. Then came the dreaded #7. At first glance, it looks like it’s impossible. I didn’t have any kind of wrench that would go on it from the outside and still have room to turn. Removing the injector and return line might help, but I really didn’t want to do that. The trick is to go at it from the driver’s side. Yes... there’s an opening that allows a long extension to go behind the turbo and down to the plug. A wobble extension and a u-joint gave me the correct angle. However, there was not enough room under the turbo heat shield to get the deep socket over the top of the plug. So, tip #2, I cut about 1/2" off the socket (making it about 1-3/8" long) to give me more clearance. (This shorter socket would have been a help on the plug under the injector lines (#4) on the driver’s side as well). Once the plug is fully unscrewed, it won’t lift straight out (again because of the heat shield), so it needs to be tipped back towards the turbo a bit to come out. Installing the new #7 plug was a snap with the hose trick, again going at it from the driver’s side.
So, with the exception of the one plug, it wasn’t a bad job at all. My WTS light now stays on for 12 seconds or so. I was fortunate that there were no swollen tips or carbon build up. Once they were broken loose, I was able to unscrew them with just the rubber hose. Point being... if you have one that doesn’t come out very easily, stop what you’re doing and come here for help. There are lots of posts dealing with stuck/broken glow plugs. Don’t make the situation worse by forcing it.
Hope this helps out anyone thinking about doing this job for the first time.
There aren’t many repairs that I’ll shy away from, but this one had me a bit spooked, what with all the horror stories about stuck plugs and broken tips. But, with the colder weather lately, my truck was becoming harder to start, and my WTS light was only staying on for 6-7 seconds. So, I checked each plug with a test light and found one bad one. I decided to replace the whole set, since after nearly 20 years of service, I figured more might be on the verge of failure.
When my new ZD9’s arrived ($80.08 delivered from RockAuto, btw), I was ready to jump in. Removal of the air cleaner assembly (ATS 093 turbo) makes everything pretty accessible, except for the plug under the turbo (#7). On an N/A engine, access would be a piece of cake. I started with the easy ones (driver’s side). All of them came out without a fuss. Quite frankly, I was surprised at how easy they were to break loose and unscrew. A great tip (I think I read it on this forum, so thanks to whoever posted it) is to use a length of rubber hose pushed over the end of the plug to unscrew it, and to get the new one started in the hole and screwed in. This is much easier than trying reach in there with your fingers, and it basically eliminates the danger of cross threading. When installing the new ones, take note of the torque spec on these (12 in lbs). That’s nothing! Just finger tight with a 1/4 inch ratchet if you don’t have an in/lb torque wrench.
On the passenger’s side, the first two (front to back) were easy. The next one (#5) was a little tricky, but not too bad. Then came the dreaded #7. At first glance, it looks like it’s impossible. I didn’t have any kind of wrench that would go on it from the outside and still have room to turn. Removing the injector and return line might help, but I really didn’t want to do that. The trick is to go at it from the driver’s side. Yes... there’s an opening that allows a long extension to go behind the turbo and down to the plug. A wobble extension and a u-joint gave me the correct angle. However, there was not enough room under the turbo heat shield to get the deep socket over the top of the plug. So, tip #2, I cut about 1/2" off the socket (making it about 1-3/8" long) to give me more clearance. (This shorter socket would have been a help on the plug under the injector lines (#4) on the driver’s side as well). Once the plug is fully unscrewed, it won’t lift straight out (again because of the heat shield), so it needs to be tipped back towards the turbo a bit to come out. Installing the new #7 plug was a snap with the hose trick, again going at it from the driver’s side.
So, with the exception of the one plug, it wasn’t a bad job at all. My WTS light now stays on for 12 seconds or so. I was fortunate that there were no swollen tips or carbon build up. Once they were broken loose, I was able to unscrew them with just the rubber hose. Point being... if you have one that doesn’t come out very easily, stop what you’re doing and come here for help. There are lots of posts dealing with stuck/broken glow plugs. Don’t make the situation worse by forcing it.
Hope this helps out anyone thinking about doing this job for the first time.
