Another car just pulled into your bay with a check engine light on. Already, you know that this could be a result of many different things. Automatically, you go to your scanner in hopes of having a clue that might make this process just a bit easier. But wait! You are getting three different codes. This is what one SureTrack community member experienced with a 2006 Lincoln Navigator 5.4 that pulled into his shop. Let’s take a look at how a simple part can cause your customer’s vehicle to have a seemingly unrelated issue.
The Diagnosis
After using the scan tool, the technician found three codes: P0301 – Cylinder 1 Misfire Detected; P0316 – Engine Misfire Detected On Startup (First 1,000 Revolutions) and P1725 Insufficient Engine Speed Increase During Self-Test. Using the scan tool again, he monitored live data as he test drove the vehicle and found cylinder 1 was misfiring. With this information, he visually inspected the engine and found no visible faults; however, he did recognize an engine coolant odor.
The technician inspected the engine coolant level and found the engine coolant was below its proper level. Taking a closer look, he also found that the engine coolant had actually come from what appeared to be a damaged hose clamp that had leaked into the cylinder 1 spark plug well. It was causing a short with the ignition on that cylinder, which prevented the engine from properly controlling RPM during the self-test functions.
The Fix
After realizing the hose was damaged, the technician replaced the hose clamp and cleaned up the engine coolant from the spark plug well. Thanks to the good work of our SureTrack technician’s RealFix, you won’t have to scratch your head wondering what to do with this combination of codes.
Real Fixes from Mitchell 1’s SureTrack® expert information resource are documented issues from actual shop repair orders and community discussions. Read the Real Fix in the Mitchell 1 ShopConnection Blog.
