Nubira Diesel: Oil Pressure Warning Points to Urgent Fix

Had the exact same issue on my 2003 Chevy Lacetti diesel last year. Being somewhat familiar with diesel engines, I first suspected the oil pressure sensor, but it turned out to be worse. The symptoms matched yours perfectly, oil pressure warning staying on and nasty engine noise. Workshop diagnosed a complete oil pump failure. They found metal shavings in the oil pan, which was pretty concerning. The oil pump wasn't building enough pressure, causing insufficient lubrication. Total repair came to 755 including parts and labor. They had to replace the entire oil pump assembly and flush the system to remove any metal particles. Fixed the problem completely, no more warnings or noise. What's your current oil level and when was your last oil change? Also, does the noise get worse at higher RPMs? This info would help determine if you're facing the same issue. Better get it checked soon, oil pump failure can cause serious engine damage if left unchecked.

Thanks for sharing that insight. My oil level looks fine and I had my last service at 149,497 KM, about 2 months ago with fresh engine oil and filter. The noise definitely gets louder with higher RPMs, and it sounds most prominent from the front of the engine block. Going to have it checked this week since I don't want to risk major engine damage. The oil leakage check showed no visible drips or signs under the car, so I'm also suspecting it could be the oil pump or pressure sensor. The noise started pretty suddenly, which makes me nervous about internal damage.

The sudden noise onset combined with the oil pressure warning definitely points toward the oil pump in my experience. When this happened with my Lacetti, the noise started abruptly too, even though the oil level and recent maintenance were fine, just like your case. Here's something I learned during my repair, a properly functioning oil pressure gauge would have caught this earlier. The warning light only comes on when pressure drops dangerously low, while a gauge shows gradual pressure changes. Since you mentioned no visible leaks and recent oil change, I'd say you're dealing with an internal oil pump failure similar to what I experienced. My mechanic explained that these oil pumps can fail suddenly due to worn components or debris in the system. The increased noise at higher RPMs matches my symptoms exactly, it's because the engine needs more oil flow at higher speeds, but the failing pump can't deliver. One suggestion, ask them to check the oil filter too. My clogged oil filter contributed to the problem, even though it was relatively new. Sometimes metal particles from the failing pump can quickly clog a new filter. Don't drive it more than necessary until the repair. I learned the hard way that even short drives with low oil pressure can cause serious engine wear.

Thanks for the detailed feedback. This sounds exactly like what I'm experiencing. I'm definitely worried it's the oil pump now since the symptoms match yours so closely. The rpms/noise connection is making more sense too, it's probably starved for oil when the engine needs it most. Just called the workshop and moved my appointment up to tomorrow morning. You're right about not risking it, I've parked the car and will have it towed there. The last thing I need is blown engine bearings from running it with low oil pressure. I'll ask them to check both the oil pump and filter, plus have them look for any metal particles in the oil pan. Smart point about the oil pressure gauge too, might get one installed while it's in there to catch any future issues early. Will update once I get the diagnosis, but at this point, I'm preparing myself for an oil pump replacement based on how similar this is to your situation.