Diesel Performance Drop? Check These Power-Robbing Issues

Had nearly identical issues with my 2016 Chevy Colorado diesel at 130K km. The symptoms matched yours exactly, power loss, excessive fuel consumption, and persistent check engine light. Initially thought it was piston rings, but diagnostic testing revealed failed fuel injectors that were causing incomplete combustion. This led to carbon buildup in the intake manifold and eventually damaged the turbocharger seals. The initial injector problem cascaded into a bigger issue because I kept driving it hoping it would sort itself out. Get it checked soon, this isn't something that fixes itself. My delayed response led to having to replace both injectors and the turbocharger. The underlying injector issue was causing unburned fuel to wash down cylinder walls, which explained the high fuel consumption. Quick tip: When you visit the mechanic, ask them to specifically: Test fuel pressure at the rail, Check injector spray patterns, Inspect turbocharger shaft play, Run a cylinder compression test These checks will pinpoint whether you're dealing with injectors or deeper engine issues like piston rings.

Thanks for sharing that experience, it really sounds similar to what I'm dealing with. Ended up taking it to another shop yesterday based on your advice, and they're also pointing to fuel injector problems rather than the piston rings the first place suggested. They're running those tests you mentioned now. Real worried about potential turbocharger damage since I've been driving it like this for a few weeks. Do you remember roughly what the final repair bill came to for your injectors and turbo work? Also, has everything been running smooth since the fix, or have you noticed any other issues pop up? Trying to budget for worst-case scenario here, especially if there's engine knocking or other problems hiding behind the initial symptoms.

After the full repair job was done on my S10, everything's been running like clockwork. The cylinder pressure fluctuation cleared up completely, turns out it was just a consequential issue from the faulty fuel injectors. Best part? The second shop didn't charge me a dime for fixing that specific problem since it was directly linked to the original fuel injector failure they were already working on. My turbo ended up being okay since I caught it early enough, but I did need two new fuel injectors. Pro tip: if you're hearing any knocking sounds, make sure they check the camshaft and timing belt while they're in there. Sometimes these issues can be related, and it's cheaper to catch everything at once. The engine's been performing great since the fix, fuel economy is back to normal, power delivery is smooth, and no more check engine light. It's definitely worth getting it sorted properly rather than letting it drag on like I initially did with mine. Getting those spark plugs checked might be worthwhile too while they're at it, they can get fouled up when fuel injectors aren't working right.

Wanted to update everyone on how this turned out. Took all your advice and went to a different mechanic last week. Glad I did because the diagnosis was spot on, bad fuel injectors were the main culprit. Had them run all the suggested tests, and while the turbocharger showed some wear, it wasn't completely shot. Final repair included replacing two fuel injectors and cleaning the intake manifold. The camshaft looked fine during inspection, and compression tests came back normal. Bill came to less than expected since catching it before the turbocharger failed completely saved me from a much bigger repair. Engine's running way better now, got my power back and fuel consumption is normal again. Check engine light finally stayed off. Shop did a great job explaining everything and showed me the old injectors, they were pretty messed up. Definitely learned my lesson about getting a second opinion when something feels off. Really relieved it wasn't the major engine overhaul the first place suggested. Thanks for helping me avoid what could've been a much more expensive repair.