[huskiemobileman]

How far should a glow plug sit in the engine? I am tightening them down till they are pretty snug in the engine. Thing is is that some have threaded all the way into the engine till there is no threads left, others only about half way. Is this normal? This is on a '94 IDI with ZD9's. Thanks.

 

[tim94f250]

All of my glow plugs bottom out on the threads. As long as they are not leaking, you should be good to go. What tool are you using to tighten them? I use a 1/4" ratchet with extension and deep socket. I see why you are questioning the depth of the glow plug in the pre-chamber. Zigg will know the answer to that.

 

[huskiemobileman]

[ QUOTE ]
All of my glow plugs bottom out on the threads. As long as they are not leaking, you should be good to go. What tool are you using to tighten them? I use a 1/4" ratchet with extension and deep socket. I see why you are questioning the depth of the glow plug in the pre-chamber. Zigg will know the answer to that.

[/ QUOTE ]

Using a deep socket with 1/2 drive. On some I had to use 1/4 drive to get past the fuel lines. One of the ones I tightened with the 1/2 drive only went half the way in. Didn't want to tighten it too much, especially with a 1/2 drive.

 

[tim94f250]

Did you notice any difference in the condition of the glow plugs when you took them out? Does it start ok? As long as you don't get any black marks at the base of the glow plugs and it starts all right, I wouldn't worry too much about it. Tim

 

[cdnsarguy]

GPs all go in the same depth, I would remove the ones which are protruding and check the GP hole for carbon buildup at the sealing base. Report back with results........

 

[icanfixall]

The glow plugs have a seat that is where they seal exhaust gas from escaping past them. The threads do nothing more than allow them to be threaded into the head. I'll bet what you have is carbon buildup because someone didn't screw them in all the way before you. Like Pete said, pull them and clean out the carbon buildup. /ubbthreads/images/graemlins/smokin.gif

 

[cdnsarguy]

If there is carbon in the GP holes don't just knock it into the cylinder, any amount of carbon can jamb up againt the piston top and head and could bend a rod.......... You may have to bring the piston to TDC and remove the injector to use a vacuum cleaner to suck the carbon out. You will require new copper washers on the injectors removed.........also if the return lines and caps are old you may be required to replace them too.........dog chasing it's tail syndrome.

 

[icanfixall]

I was just on Ebay and found a good picture of the glow plug compression seat. This is the item number...7986505031. They are Bosh but all are the same type that fit our motors /ubbthreads/images/graemlins/smokin.gif