This is a very common problem with the 2003 chev Trailblazer. It's a poor design in my opinion that the #2 and #3 coils are deprived of air because of the design of the engine and the air breather covers. I have had to replace this same coil on numerous vehicles of this year, make, model and engine size. <br />Another common problem is the fan clutch locking up causing the vehicle to lose power and sound like an airplane taking off. If you have this type of vehicle and a similar problem, save yourself some time of diagnostics and taking it to a mechanic, just watch this video and change the parts yourself. Your will save several hundred dollars.<br />If you live in the metairie or New Orleans area and you need service on your vehicle, you can call me or go to my website and sign up for a repair at www.jakesmobileautorepair@gmail.com or call 504-723-2996.<br />Also check out my other video's and tips of the day on my youtube channel. click the link below<br />www.youtube.com/c/jakesmobileauto
