Difference between intake and exhaust cam phasers?
Beeps and Boops
Joined: Oct 2020
Posts: 2,662
Likes: 1,785
From: Iowa
https://www.f150forum.com/f118/cam-p...3/#post7798921
If you documented your request for OEM phasers and they obviously didn't use OEM, they'll probably fight you but you're right.
If they believe there's an oil pressure issue, they can perform the oil pressure tests and back it up, otherwise they're blowing smoke and ducking responsibility.
Last edited by Laminar; Oct 21, 2025 at 01:42 PM.
Senior Member
Joined: Mar 2021
Posts: 4,767
Likes: 2,375
303 it's me again.
.
The Phasers are mechanically designed the same for operation.
The internal >>>calibration<<< is what is different between them for operating range and action that makes them non interchangeable for operation.
.
If reversed, the position timing goes to h*ll and codes would be produced.
.
If chain Sync is off to far, there is risk of Valves open at the wrong point as Pistons come up, then internal damage is done.
This is one reason high compressions are possible with flat Head pistons and only small crown reliefs.
Mechanical parts Sync and timing changes become all important and have to all work together within limits.
The results of all this is a wide engine Torque range under computer control and Phaser action range.
It all has to work together within the range limits.
The position Sensors report the timing, so the program knows where "everybody" is. If not in correct timing, codes are set. They are the watch dogs of the whole operation.
Going back one more step; the Crank Position Sensor is the base timing reference, and it can actually be off, if not in calibration position with the >Crank position that runs the Valve Train via the Chain drives.
It's a big timing circle. Anything that is out of timing positions gets reported and can result is drivability issues.
Good luck.
.
The Phasers are mechanically designed the same for operation.
The internal >>>calibration<<< is what is different between them for operating range and action that makes them non interchangeable for operation.
.
If reversed, the position timing goes to h*ll and codes would be produced.
.
If chain Sync is off to far, there is risk of Valves open at the wrong point as Pistons come up, then internal damage is done.
This is one reason high compressions are possible with flat Head pistons and only small crown reliefs.
Mechanical parts Sync and timing changes become all important and have to all work together within limits.
The results of all this is a wide engine Torque range under computer control and Phaser action range.
It all has to work together within the range limits.
The position Sensors report the timing, so the program knows where "everybody" is. If not in correct timing, codes are set. They are the watch dogs of the whole operation.
Going back one more step; the Crank Position Sensor is the base timing reference, and it can actually be off, if not in calibration position with the >Crank position that runs the Valve Train via the Chain drives.
It's a big timing circle. Anything that is out of timing positions gets reported and can result is drivability issues.
Good luck.
Last edited by Bluegrass; Oct 21, 2025 at 02:13 PM.
Thread Starter
Senior Member
Joined: Jan 2025
Posts: 306
Likes: 177
From: Denver, CO
303 it's me again.
.
The Phasers are mechanically designed the same for operation.
The internal >>>calibration<<< is what is different between them for operating range and action that makes them non interchangeable for operation.
.
If reversed, the position timing goes to h*ll and codes would be produced.
.
If chain Sync is off to far, there is risk of Valves open at the wrong point as Pistons come up, then internal damage is done.
This is one reason high compressions are possible with flat Head pistons and only small crown reliefs.
Mechanical parts Sync and timing changes become all important and have to all work together within limits.
The results of all this is a wide engine Torque range under computer control and Phaser action range.
It all has to work together within the range limits.
The position Sensors report the timing, so the program knows where "everybody" is. If not in correct timing, codes are set. They are the watch dogs of the whole operation.
Going back one more step; the Crank Position Sensor is the base timing reference, and it can actually be off, if not in calibration position with the >Crank position that runs the Valve Train via the Chan drives.
It's a big timing circle. Anything that is out of timing positions gets reported and can result is drivability issues.
Good luck.
.
The Phasers are mechanically designed the same for operation.
The internal >>>calibration<<< is what is different between them for operating range and action that makes them non interchangeable for operation.
.
If reversed, the position timing goes to h*ll and codes would be produced.
.
If chain Sync is off to far, there is risk of Valves open at the wrong point as Pistons come up, then internal damage is done.
This is one reason high compressions are possible with flat Head pistons and only small crown reliefs.
Mechanical parts Sync and timing changes become all important and have to all work together within limits.
The results of all this is a wide engine Torque range under computer control and Phaser action range.
It all has to work together within the range limits.
The position Sensors report the timing, so the program knows where "everybody" is. If not in correct timing, codes are set. They are the watch dogs of the whole operation.
Going back one more step; the Crank Position Sensor is the base timing reference, and it can actually be off, if not in calibration position with the >Crank position that runs the Valve Train via the Chan drives.
It's a big timing circle. Anything that is out of timing positions gets reported and can result is drivability issues.
Good luck.
5 Year Member
Joined: Oct 2018
Posts: 20
Likes: 19
Oh man, new oil pump to go with the NON-OEM phasers for higher oil pressure. I can only imagine how fun that procedure would be. 
. My man, I feel your frustration. If you were in Southern Cali, I would offer to truck my tools over and help you work on yours. After doing the ecoboost, the non-EB would be a piece of cake since you don't have to deal with all the turbo piping's.
. My man, I feel your frustration. If you were in Southern Cali, I would offer to truck my tools over and help you work on yours. After doing the ecoboost, the non-EB would be a piece of cake since you don't have to deal with all the turbo piping's.
Thread Starter
Senior Member
Joined: Jan 2025
Posts: 306
Likes: 177
From: Denver, CO
I think he meant that the Ford part numbers someone posted were for the 3.5. The Coyote and EcoBoost phasers are different.
https://www.f150forum.com/f118/cam-p...3/#post7798921
If you documented your request for OEM phasers and they obviously didn't use OEM, they'll probably fight you but you're right.
If they believe there's an oil pressure issue, they can perform the oil pressure tests and back it up, otherwise they're blowing smoke and ducking responsibility.
https://www.f150forum.com/f118/cam-p...3/#post7798921
If you documented your request for OEM phasers and they obviously didn't use OEM, they'll probably fight you but you're right.
If they believe there's an oil pressure issue, they can perform the oil pressure tests and back it up, otherwise they're blowing smoke and ducking responsibility.
Thread Starter
Senior Member
Joined: Jan 2025
Posts: 306
Likes: 177
From: Denver, CO
Oh man, new oil pump to go with the NON-OEM phasers for higher oil pressure. I can only imagine how fun that procedure would be. . My man, I feel your frustration. If you were in Southern Cali, I would offer to truck my tools over and help you work on yours. After doing the ecoboost, the non-EB would be a piece of cake since you don't have to deal with all the turbo piping's.
. My man, I feel your frustration. If you were in Southern Cali, I would offer to truck my tools over and help you work on yours. After doing the ecoboost, the non-EB would be a piece of cake since you don't have to deal with all the turbo piping's.
Thread Starter
Senior Member
Joined: Jan 2025
Posts: 306
Likes: 177
From: Denver, CO
303 it's me again.
.
The Phasers are mechanically designed the same for operation.
The internal >>>calibration<<< is what is different between them for operating range and action that makes them non interchangeable for operation.
.
If reversed, the position timing goes to h*ll and codes would be produced.
.
If chain Sync is off to far, there is risk of Valves open at the wrong point as Pistons come up, then internal damage is done.
This is one reason high compressions are possible with flat Head pistons and only small crown reliefs.
Mechanical parts Sync and timing changes become all important and have to all work together within limits.
The results of all this is a wide engine Torque range under computer control and Phaser action range.
It all has to work together within the range limits.
The position Sensors report the timing, so the program knows where "everybody" is. If not in correct timing, codes are set. They are the watch dogs of the whole operation.
Going back one more step; the Crank Position Sensor is the base timing reference, and it can actually be off, if not in calibration position with the >Crank position that runs the Valve Train via the Chain drives.
It's a big timing circle. Anything that is out of timing positions gets reported and can result is drivability issues.
Good luck.
.
The Phasers are mechanically designed the same for operation.
The internal >>>calibration<<< is what is different between them for operating range and action that makes them non interchangeable for operation.
.
If reversed, the position timing goes to h*ll and codes would be produced.
.
If chain Sync is off to far, there is risk of Valves open at the wrong point as Pistons come up, then internal damage is done.
This is one reason high compressions are possible with flat Head pistons and only small crown reliefs.
Mechanical parts Sync and timing changes become all important and have to all work together within limits.
The results of all this is a wide engine Torque range under computer control and Phaser action range.
It all has to work together within the range limits.
The position Sensors report the timing, so the program knows where "everybody" is. If not in correct timing, codes are set. They are the watch dogs of the whole operation.
Going back one more step; the Crank Position Sensor is the base timing reference, and it can actually be off, if not in calibration position with the >Crank position that runs the Valve Train via the Chain drives.
It's a big timing circle. Anything that is out of timing positions gets reported and can result is drivability issues.
Good luck.