Low Power when hot and at low RPM only

Old Jul 9, 2025 | 08:21 AM
  #11  
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Cylinder 1 is furthest to the passenger side. Intake valves are toward the front of the car. So when the cam lobes for cylinder 1 on the intake cam are both pointing straight down, this is where you check the intake reluctor ring. Cylinder 4 is closest to the driver, and the exhaust cam is closest to the firewall. So when the cam lobes for cylinder 4 on the exhaust cam are pointing straight down, this is where you check the exhaust reluctor ring. Based on the few YouTube videos I've seen on this issue, it's always the exhaust cam reluctor ring that's out of position.
 
Old Jul 9, 2025 | 08:34 AM
  #12  
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[QUOTE=oldmarine;79072]
Thank you for your quick response, I was able to verify the information you gave me.See attached photos On the intake with the cam lobes down there are a few degrees off. But as you predicted, the exhaust is actually worse. So I have to change the cams and phasers ?Thanks again.


 

Last edited by Korvicus; Jul 9, 2025 at 08:39 AM.
Old Jul 9, 2025 | 09:05 AM
  #13  
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In the first picture, I can see that the cam lobes for #4 are straight down, and the reluctor ring appears to be 30 to 40 degrees off (based on the guidance from the service bulletin). The intake cam also appears to be off the same amount in the second picture. Were the #1 (not #4) intake cam lobes pointed straight down in the second picture?

In any case, if the reluctor rings are not properly phased, you need to replace the respective cam(s). I believe the phasers/actuators for the variable cam timing are part of the cam gears on the 2.4L engine. These would not need to be replaced if everything else on them looks good.
 
Old Jul 9, 2025 | 09:24 AM
  #14  
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Thanks, Yes, position number 1 and number 4 are at the very bottom. I checked them separately.Camshafts are quite expensive. However, I'm really glad someone managed to figure out the problem. I really appreciate the time you took to reply.
I think I'll put the project on hold for a while. As soon as I complete the repair, I'll let you know.Thanks again.
 
Old Jul 9, 2025 | 09:49 AM
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For information, your earlier pictures show that your mechanical valve timing is set correctly. The variable valve timing actuators have about 50° (crankshaft) authority over the valve timing, depending on speed, load, etc. as determined by the ECM. So the engine will probably run normally with low power demands and in open loop. But when the ECM decides to vary the valve timing to adjust to other conditions, it's getting feedback information from the cam sensors that are not what it is expecting, hence the P0016/P0017 DTCs.
 
Old Jul 9, 2025 | 08:28 PM
  #16  
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Is it possible that one or both cam phasers are malfunctioning? I will look at the service manual online to educate myself on the proper diagnostics. My Lincoln Navigator has cam phasers and it still runs as new. It has 245k miles and has had 5/20 full synthetic in it since new with changes at 5k mile intervals.
 
Old Jul 11, 2025 | 09:50 AM
  #17  
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I think we made a mistake.According to the bulletin instructions, the camshaft lobes should be at the top because the valves should be open and not closed as I thought I have to do the tests again tonight or tomorrow and I'll keep you posted.Unless I'm mistaken
 
Old Jul 11, 2025 | 10:17 AM
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The valves are opened when the cam lobe rotates to the bottom, depressing the cam follower ("rocker") which opens the valve. The camshaft lobes should be pointing straight down to fully open the valves.
 
Old Jul 11, 2025 | 10:50 AM
  #19  
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[okay thanks.
What made me think I had made a mistake was the picture of a brand new camshaft. See attached photo

 
Old Jul 11, 2025 | 01:28 PM
  #20  
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Overhead cam
 

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