DenLorsTools.com Summary: Duramax diesels that have misfires at low RPM’s and under a load could have faulty glow plugs. In extreme temperatures like in the middle of the summer or winter these type of problems are more likely to occur. In extreme winter weather is when most of our customers report issues. Usually when trying to change a glow-plug a common problem is breaking. That’s when our phones start ringing and the most orders for our W900-0199’s come in through our two websites (DenLorsTools.com and WiseAutoTools.com). We are providing this tech article to inform our customers about options for removing broken glow plugs without removing the cylinder head.

While GM does not make a tool kit for broken glow plug removal on the Duramax, many of our customers have been successful using the W900-0199 which is actually designed for removing broken glow plugs in Sprinter 5 Cylinder Diesels. Not all of these kits although they may look similar, are the same. The Duramax glow plug has a larger center core than the Sprinter. For example, we sell the B900-0199 broken glow plug remover, that looks similar to the W900-0199. The W900-0199 has larger core step drill bits and mandrels. This makes the W900-0199 more effective when working on the Duramax. Many times the entire kit does not have to be used. Sometimes the Duramax broken glow plugs can be removed by using the special step drill bits and the drilling adapter that extends the reach. In some cases they just loosen up when drilling and can be removed. In some other cases the rest of the kit like the mandrel and puller assembly needs to be used as well. One customer in Alaska told us that the puller housing does not seat perfectly so he was able to use a small 1/4″ socket under one side of the puller housing to even up the pulling pressure applied. Another customer in California, did not compensate for the uneven pulling pressure due to the way the puller sat and this resulted in successful removal of the glow plugs but the mandrels were bent in the process. We stock replacement mandrels so that was not a huge problem for our customer. He was just happy to have removed the broken glow plugs without the removal of the cylinder head like the Chevrolet dealers suggest.

Another tool kit that we often sell together with the W900-0199 is the Time Sert 5000 thread repair kit. Usually the removal of broken glow plugs does not damage the threads for the glowplugs. It’s important to note that the thread tap in the W900-0199 is not the correct thread pitch (meaning coarse or fine) as the Duramax, because the W900-0199 is actually made for the Sprinter 5Cyl. engine. The W900-0199 has an M10x1.0 tap and the Duramax uses M10x1.25 thread size for their glow plugs. If the threads are damaged in the process of removing the broken glow plugs in the Chevy Duramax, the time Sert 5000 kit can install a solid bushing type insert that accepts the new glow plug perfectly. The Time Sert 5000 kit uses an M10x1.25 aluminum insert and works for 2001 to 2010 Duramax engines. That’s why some of our customers will purchase the W900-0199 and then if the threads are damaged they purchase the Time Sert 5000. Some go ahead and purchase both at the same time so they are prepared. It’s important to realize that these are two separate kits.