All of a sudden while drving the car started running weird. Not hesitating, not bogging, and not cutting out. It's just not running right.
The engine sounds different, and I think I hear valve train noise. I have broken many rocker arms in the past and I thought that's what it was since it was running and sounding similar to when I have broken rocker shafts.
Here's what I checked.
1. It's not a broken rocker shaft. They look good.
2. I did a compression test.
3. I tested the coil pack.
4. I changed the plugs.
5. The crank sensor looks good.
6. I swapped the MAF with a new GM delco one.
7. I tested the cam sensor with the Casper's cam tool.
8. No water in the oil.
9. Reset the computer a few times.
10. No error codes.
11. No vacuum leaks.
12. TPS voltage looks good on scan tool.
13. IAC reads good.
Here's an interesting clue. The new casper's knock detector was going off like crazy as I gently drove home 2 miles.
In park when I rev the car the Casper's knock detector will go off.
So it seems like there's valve train or some other noise. If I broke a valve or something then I would think it would show up in the compression test. I don't feel like doing a leakdown test since the cylinders were able to hold the compression reading for several minutes without falling at all.
What should I check now?
The engine sounds different, and I think I hear valve train noise. I have broken many rocker arms in the past and I thought that's what it was since it was running and sounding similar to when I have broken rocker shafts.
Here's what I checked.
1. It's not a broken rocker shaft. They look good.
2. I did a compression test.
3. I tested the coil pack.
4. I changed the plugs.
5. The crank sensor looks good.
6. I swapped the MAF with a new GM delco one.
7. I tested the cam sensor with the Casper's cam tool.
8. No water in the oil.
9. Reset the computer a few times.
10. No error codes.
11. No vacuum leaks.
12. TPS voltage looks good on scan tool.
13. IAC reads good.
Here's an interesting clue. The new casper's knock detector was going off like crazy as I gently drove home 2 miles.
In park when I rev the car the Casper's knock detector will go off.
So it seems like there's valve train or some other noise. If I broke a valve or something then I would think it would show up in the compression test. I don't feel like doing a leakdown test since the cylinders were able to hold the compression reading for several minutes without falling at all.
What should I check now?