Broken Duramax Glow Plug #8
I know this network likes to focus on hard to diagnose issues and complex electrical concerns, but sometimes we face good old fashioned mechanical issues. I will start off by saying I personally own the vehicle in this discussion. The other day my wife let me know the MIL was illuminated on the truck and the glow plug light would not go out. It was a 90+ degree day so I suspected I had a glow plug issue. After scanning and diagnosing the concern, I found the #8 glow plug had come to the end of it's useful life.
The #8 glow plug is on the driver side of the truck and it is cantered towards the bulkhead (firewall). If you are familiar with these trucks, you will recall the engine is tucked neatly under the cowl. So needless to say, this glow plug is NOT in a easy to service location. After removing the inner fender liner, I blasted the glow plug with penetrating oil and then my favorite concoction of ATF and acetone. I attempted to remove the glow plug using a universal joint and a 24" extension without success. I continued to soak down the glow plug, heat cycle the engine, etc. Unfortunately, the glow plug was seized in the cylinder head and head of the glow plug eventually snapped off.
I began the mad search to see if anyone had any success removing a broken #8 glow plug, and almost every credible resource I looked at stated the cylinder head needs to come off. Being determined to find a better way, I found out that a glow plug extractor kit exists. The price of the kit ranged from $40 to $350. All of the kits looked exactly the same (b…d on the pictures). I rolled the dice and purch…d the $40 kit from my favorite online retailer. 2 days later, I had the kit in hand and ready to go.
Unfortunately, there was no easy way to access the glow plug at the correct angle. The cab was blocking my 90 degree drill and I was dead in the water again. After sleeping on the situation, I recalled how I used to have to lift the body off the early GM S10/S15 trucks to access the top 2 transmission bolts. I called up a buddy who is also a tech at a local Ford dealership and we proceeded to jack the crew cab up off the frame. The only things we needed to do was remove the master cylinder from the hydro-booster, separate the intermediate steering shaft, and disconnect the parking brake cable. We lifted the body high enough to slip a 4x4 block between the frame and body mounts. This gave us enough clearance to drill out the glow plug. The extractor kit worked flawlessly and it was the best $40 I had spent in a long time. The only downer of the entire process was I ended up installing a tread repair coil to the head. My drilling skills we not absolutely perfect. I would have likely been able to do the repair without the thread repair kit had I lifted the body high enough the first time.
Ultimately, the entire job cost me $150 in parts and about 10 hours of labor. Obviously, in the future I could do this job in 2-3 hours at very most now I know the tricks. I wanted to share my story in an effort to help someone else in the same situation. 2-3 hours is much better than pulling the head. Feel free to reach out to me if you have specific questions.