A little background: I am not a mechanic. I’m a Youtube watcher and follow directioner. I try to do what I can to save money but also learn something new. There is little more satisfying than successfully completing a challenging repair. I often use the cost savings to buy extra tools or equipment. In the past few years, I’ve replace a starter, diagnosed and replaced a throttle position sensor (TPS), replaced a few power window switches. I’ve tried and failed a few repairs – like fixing the air conditioning. I also do routine maintenance like oil changes, air filter changes, rotating tires.
This car I’m working on had been in the family for about 7 years since we ran a livery limo service. It began life as a rental car, then we bought it about 6 months old. We ran it as a limo for a few years before retiring it to personal use.
The latest issue began slowly. Engine was idling rough, seemed to be hesitating or revving while driving. Then started throwing P0306 code, indicating engine misfire on cylinder 6. The vehicle has about 130k miles to its name. I know it had a tune-up around 50k miles. But it’s since been used as a livery vehicle and then subject to dirty, rough, rugged mountain conditions, so it’s overdue for a tune-up.
I know the spark plugs haven’t been changed in a long time, and wires never. I got and fixed throttle position sensor problems about six months ago but was still having some misfire codes and rough running. I knew it needed plugs and wires and bought them last November, 2019. Without indoor garage to work on it, I was waiting for some good weather. Finally came, almost June 2020.
I started once a few months ago, but found Cylinder #8 impossible. I watched a bunch of videos, including this one How To Remove Spark Plug #8 on a 2010 Yukon XL SLT 1500 (5.3L V8) and this one How to remove and replace #8 cylinder spark plug GM 5.3 Vortec. Both recommend using multiple up/down sizes. I ended up getting a short 3/8 drive 1-1/2″ extension for about $5 on ebay, which worked perfect…. but I had to wait until that perfect weather again. I didn’t need to remove any covers, dipsticks, wheel well covers, or anything crazy as described in some videos. Just the short socket extension.
After getting the short extension for cylinder #8 and removing it first – and pretty easily – everything was going well. Until cylinder #2 (I think, it’s the very front cylinder on passenger side.) Manufacture specs said something like ’10-14 lbs’ for 5.3 Vortec spark plug torque. I had a torque wrench and set it to 12 lbs. And SNAP…. if you ever want to see a grown man cry, watch him snap off a spark plug in an engine block.
Here is my cost savings to replace spark plugs and wires on a 2013 GMC Yukon XL 1500 with 5.3 Vortec Engine. Shop prices, according to one of my favorite auto repair estimators, would be $520 at a private repair shop or $659 at the dealer. I did it myself and my total cost was $202, which included a few new tools and piece of equipment.
Here’s what I bought:
ACDelco Iridium Spark Plug 41-162 – AutoZone with coupon $55
ACDelco Wireset 748UU – AutoZone with coupon $65
Inspection camera – Harbor Freight with coupon $68
Screw extractor – Lowes $9
Socket extension – Ebay $5
Over the next few days, I consulted with a friend who previously worked for a large auto parts manufacturer. He’s got a great working knowledge of the engine, and spark plugs. He referred me to this page about removing a broken spark plug. It suggested a square extractor, but try finding one! I went to Auto Zone, Ace Hardware, Lowes, Tractor Supply, and Harbor Freight. Nope, no square extractors. I purchased five different options from 3 different stores. This is the one that worked… an Irwin Hanson EX-4 Spiral Flute Extractor as found in this set. I was about to give up, when a neighbor stopped by and gave me a little encouragement, and suggested how to use the extractor without loosing it in the engine. I duct taped it to the socket.
I’m sure that I wasn’t putting ‘excessive force’ on this spark plug. The torque wrench was set to 12lbs per inch, and I had tightened several other spark plugs before this one snapped off. I wonder if AC Delco 41-162 Spark Plug was defective? Bad batch? Well it certainly ruined a few days for me, and cost a lot of time and money to fix. But I lucked out.
As my friend had suggested, I got an inspection scope to get a closer look. I ran down to my local Harbor Freight, with a 20% off coupon, and picked up an inexpensive scope. Something like this, but I think it’s a different model: CEN-TECH Digital Inspection Camera. I looked in the cylinder and it looked a little corroded, but I didn’t see any metal pieces or anything. Put the replacement AC Delco plug in, and took it for a few dozen mile ride around town, freeway, didn’t throw any codes and seemed to run better than it has in years! Another Youtube Mechanic job successfully done!