Diesel Glow Plug Failure Causing Rough Cold Starts

As someone who works regularly on diesels, I had a very similar issue with my 2010 Chevy Cruze diesel. The engine light came on and cold starts became really rough, just like you're describing. After proper diagnosis, the glow plug was indeed faulty, causing poor engine combustion during cold starts. The repair involved replacing two defective glow plugs, which set me back about 440 in total at my local shop. Before jumping to conclusions, could you share: Current mileage, How long has the preheat light been staying on? Any other warning lights showing up? Engine performance in warm conditions? The diesel engine symptoms you're describing match my experience exactly, but proper diagnosis is crucial since similar symptoms can point to different issues in the Sail's diesel engine system. What I learned from my case: don't wait too long if you suspect glow plug issues. Continuing to drive with faulty glow plugs can lead to starting problems and potentially more expensive repairs down the line.

Thanks for the feedback. The preheat light has been staying on for about 2 weeks now. My Sail's at 10310 KM since the latest service. Besides the preheat indicator, check engine light flickers occasionally during cold starts. The rough idle only happens during cold starts, once the engine warms up, it runs pretty smooth with normal fuel efficiency. This makes me more confident it's related to the glow plugs rather than a bigger engine combustion issue. Going to get it checked out this week before it potentially causes more problems.

Thanks for the additional details. Based on those symptoms and mileage, I'm even more convinced it's similar to what I experienced with my Cruze. The pattern of rough idle during cold starts that improves after warm-up, combined with the flickering check engine light, matches exactly what I dealt with. When I waited those extra weeks before fixing mine, I noticed my fuel efficiency started to drop slightly during cold weather. The glow plug issue caused incomplete engine combustion during startup, which meant the engine was working harder than necessary. A quick tip from my repair: have them check all glow plugs while they're at it. In my case, when they tested all of them, they found a second one was close to failing too. Replacing both at once saved me from another repair visit a few months later. The relatively low mileage since your last service suggests this isn't a maintenance-related failure, sometimes glow plugs just go bad. Getting it sorted now is definitely the right call before winter makes cold starts even more challenging.

Thanks for this detailed advice. You've convinced me to get all the glow plugs checked at once. The symptoms with the check engine light and rough idle match my situation perfectly, and I don't want to risk having to do this repair twice. Just scheduled an appointment for tomorrow morning. Having the complete glow plug set inspected makes total sense since I'm already paying for the labor. The engine combustion issues during cold starts are getting worse, so fixing it now before winter seems like the smart move. Will update once I get the final diagnosis and repair completed. From what you've shared, at least I now have a better idea of what to expect cost-wise and can feel more confident it's not a major engine problem.