[hostacruze]

I have a 1.8 engine. At the beginning of each day, when I start the car, no error code appears. However, if I turn off the engine and restart it, code P0016 appears. I have checked the timing belt multiple times, and there is no issue with it.
- The issue persists throughout the day no matter how many times I try to clear the code. The only way for it to disappear is if I leave the engine off for more than 6 to 8 hours, or until the next day. As I mentioned, so the code does not appear on the first start of the day. The car runs fine all the day with no issues if i dont turned it off and restarted it

 

[hostacruze]

I use 5w30 oil, and if there is a problem with the oil, why is it that every morning, in the first start of the engine, the P0016 code doesn't appear, and the car has stronger torque? Even if I drive it all day, it remains fine as long as I don't turn off the engine. But as soon as I turn off the engine and restart it, the P0016 code comes up as PENDING

 

[hostacruze]

I finally managed to solve this issue, which had been troubling me for a long time, and I found an easy yet astonishing solution.

Before discussing the solution I discovered, here are some observations that led me to it:

As mentioned earlier in the post, the car behaved normally during the first engine start. Let’s call this startup "A." However, if I turned off the engine and restarted it—even if it was still cold—the P0016 code would appear. Let’s call all subsequent startups "A++."

I noticed something important using the OBD scanner:

Before performing A startup, the timing advance value was 34.5°.

However, before performing A++ startup , the timing advance value was 32.5°, meaning it dropped by 2 degrees.


I don’t know exactly how the ECU calculates timing advance, but I was sure it uses the intake camshaft sensor, exhaust camshaft sensor, and crankshaft sensor. Since the P0016 code is related to the intake camshaft sensor, the 2-degree loss, which triggers the code, must be related to this sensor.

At this point, I rotated the intake camshaft sensor approximately 95° counterclockwise, as shown in the picture.

"" This is a rough diagram of the cylinder head, showing the locations of the sensors in relation to the lobes they read from""

After doing so, I started the car, and the P0016 code disappeared. I restarted the engine multiple times, and the code did not return. The car's response improved significantly, and its power was noticeably restored.

And now, the timing advance before every startup is 35°, which is definitely better than the 34.5° I used to get in the morning and much better than the 32.5°, which was causing the issue.


The only issue is that I can't insert the sensor's fixing screw since I changed its angle. However, this is not a problem because the sensor is well secured with a toric seal.

I wanted to share this solution with you in case it helps in understanding this issue or assisting others who might be facing the same problem.

Thank you all, and thanks to this forum!