On Thanksgiving Day, I replaced the factory oil pressure sensor on my GM 4.2L L6 that had 227,462 km (142,164 mi) on it, because it would intermittently show no oil pressure on the idiot gauge and cause the check gauges light to illuminate.
The replacement was an OE GM part (12635957) that was made in Mexico, just like the factory unit that was on there. I bought the part from my local friendly Chevrolet dealer; it appeared to be older stock based on the packaging, but that did not matter (at least to me).
Fast forward six months and 4,419 km (2,762 mi) and I randomly "lost" oil pressure this morning. The idiot gauge was pegged at 0 kPa/0 PSI and the check gauges light was on solid. Thinking the stepper motor went bad in the instrument cluster this time, I used my scan tool to do a "sweep" and all the gauges were functioning as intended. Although the engine was running as quiet as a church mouse, I thought the next logical decision would be to do an oil pressure test for the heck of it to verify.
The moment I removed the connector off the oil pressure sensor, I noticed it was covered in oil and it was a done deal. I went and got another OE part from the jolly GMC dealer, this time in GM's "new" packaging if it matters at all, and did a side by side comparison of both parts that were identical to the tee and both made in Mexico. Put the new one in and cleaned the connector with some contact cleaner; the idiot gauge now reads 275 kPa (40 PSI) again at idle with no check gauges light, and the PCM is happy again.
Let's hope this one lasts longer than 6 months and barely 3,000 miles. This is right up there with the Motorcraft RS-527 radiator cap I bought last month that didn't seal properly, causing coolant to overflow out the degas bottle at operating temperature. Seems asking for an OE part, in particular, to perform as intended for a reasonable length of time is asking too much these days with all the garbage that passes as "new parts".
The replacement was an OE GM part (12635957) that was made in Mexico, just like the factory unit that was on there. I bought the part from my local friendly Chevrolet dealer; it appeared to be older stock based on the packaging, but that did not matter (at least to me).
Fast forward six months and 4,419 km (2,762 mi) and I randomly "lost" oil pressure this morning. The idiot gauge was pegged at 0 kPa/0 PSI and the check gauges light was on solid. Thinking the stepper motor went bad in the instrument cluster this time, I used my scan tool to do a "sweep" and all the gauges were functioning as intended. Although the engine was running as quiet as a church mouse, I thought the next logical decision would be to do an oil pressure test for the heck of it to verify.
The moment I removed the connector off the oil pressure sensor, I noticed it was covered in oil and it was a done deal. I went and got another OE part from the jolly GMC dealer, this time in GM's "new" packaging if it matters at all, and did a side by side comparison of both parts that were identical to the tee and both made in Mexico. Put the new one in and cleaned the connector with some contact cleaner; the idiot gauge now reads 275 kPa (40 PSI) again at idle with no check gauges light, and the PCM is happy again.
Let's hope this one lasts longer than 6 months and barely 3,000 miles. This is right up there with the Motorcraft RS-527 radiator cap I bought last month that didn't seal properly, causing coolant to overflow out the degas bottle at operating temperature. Seems asking for an OE part, in particular, to perform as intended for a reasonable length of time is asking too much these days with all the garbage that passes as "new parts".