04/02/2026
"Why is my check engine light on and should I worry about a glow plug?"
A customer brought in their 2019 L5P Duramax because the check engine light popped on and they wanted to handle it before it turned into a no start morning. After testing, we found the number 5 glow plug was bad.
We started the removal and the lower half of the glow plug snapped off and stayed stuck in the cylinder head. This is the part where most people start thinking the worst. Big teardown, lots of labor, lots of downtime.
Shop Lead Evyn stepped in, explained the situation, and used the right extraction process to remove the broken section without pulling the cylinder head. The customer avoided a much bigger repair, got clear answers, and had their truck back without the extra downtime.
If you have a light on, bring it to McDiesel in Sparks, NV and we will diagnose it properly and walk you through the best fix.
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