Oil & Fuel One Glow Plug working?

eightksi · Aug 30, 2010

Wonder if anyone else may have had this problem....The Glow element in the dash heats up fine, and ONE of the three glow plugs heats--the closest one to the dash. The center plug only gets slightly warm, and the plug closest to the radiator doesn't appear to get any heat....Anyone troubleshoot this one before? I can start it OK, but I do let it heat for a good 30 sec before turning it over. The dash element's nice and hot, and it turns over and fires up fairly well, but I would think it would start better/quicker with the other two cylinders pre-heated correctly. Maybe the daisy-chained wires are old...the wire is thin in one portion between the #1 and #2 plugs. Thoughts? This is for my S470d.

Big Hammer · Aug 30, 2010

I would replace the two 'daisy chained' wires first, but I believe you will find that two of the glo plugs are bad. Also, holding the button down for 30 seconds is a little risky... you may burn them out a little prematurely. 6-8 seconds should result in cherry red glo plugs.

Mark

eightksi · Sep 27, 2010

Has anyone replaced these factory glow plugs, and had success with after-market parts, maybe NGK or Champion-brand plugs? I will call in the part numbers for a price, but I will bet, like most Satoh parts, it'll be exponentially higher than an aftermarket part.

Also, I have zero experience with diesel engines...I will probably get a volt meter on these plugs and wires first...then see what I get, but I would assume the wire between #1 and #2 might be the culprit, which is strange (to me), because the top of the wire is worn down, almost like it's been filed or rubbed down about 1/2 way....but there's nothing that comes in contact with that wire at all.

Is it basically as simple as removing these wires and plugs and replacing, or do the wires have to attach in any specific way to the plugs? I noticed there's a 'slit' on the plug where the wires connect...no idea what that's for.

dbltrbl · Sep 27, 2010

Your wire damage may be due rats. For some reason they love to shred electrical wire. On my S470 you turn the key to the left to "heat". I believe the manual says to leave it on "heat" for 20 to 30 seconds. Hope the new wire fixes the problem. Glenn

Transit · Sep 27, 2010

I dont know how your glow plugs are wired, I would fabricate a buss bar bridging all three plugs and connect the feed lead to the center plug. Copper pipe flattened will make a good buss bar. Drill holes for each plug connection. This way you will get the best connections. You may still have bad plugs too.

PILOON · Sep 29, 2010

The copper tubing buss is a good idea.
You will know if you have a dead plug as the dead ones will be cooler than a good one to the touch.

Either that method or using a voltmeter set in the low resistance range each plug will read about the same resistance, probably between 4-10 ohms for each. (note the buss bar should not be in place for the resistance test)

For the ohm meter test clip one lead to plug screw and the other is grounded to engine block.

Good luck.