Had Engine Issues, Went to work on the 5.4 & found....
Thread Starter
Junior Member
Joined: May 2012
Posts: 26
Likes: 0
From: Rogers, AR
Had Engine Issues, Went to work on the 5.4 & found....
Hey guys, some of you might remember that in June I replaced my 152k mile 5.4 with a remanufactured engine from Engines Direct. My old phasers were cashed & it burned a little oil. Long story short(ened), I had issues after the new motor was installed. Here we go...
The day I brought it home, had issues with the vacuum line from the intake manifold to brake booster. I replaced it with new 5/8" heater hose and went about my business. Well, this interfered with the action of the Charge Motion Control rods and caused them to stick open. Thus, 500 - 3,600rpm, it was a gutless turd.
I also had a CEL throw the next day. Used a scan tool, said that "System Couldn't Complete Self Test". Awesome, very specific OBDII...
I drove it like this for a while, not really concerned. I'd reset the ECU and the code would clear until I got on it really hard, then it might/might not come on. When it did, fuel mileage sucked so I assumed I was in a limp mode.
About a week ago, the truck started stalling on takeoff and jerking when up to speed between 1,800 & 2,000rpm.
I dove into it today. I ordered a new throttle body several days ago, it came in today. I pulled the intake manifold out and re-routed the vacuum line to prevent interference with the CMCV system. While the intake manifold was off, I cleaned the filthy butterflies with a carb cleaner.
Upon reinstallation, I was tracing the wiring harness on the back of the motor and found this...
Not sure if this is the Coolant Temp Sensor or the Knock Sensor lead, but the wires were twisted from the factory and had began to touch and short.
Fixed the short, reinstalled the manifold in a 10 bolt 3 stage sequence starting at 18inlbs of torque, then going to 50, stopping at 89 inch/pounds. I then installed the new throttle body, primed the fuel pump, reset the ECU and started it up.
Drove it hard for 10 minutes, then shut it off and restarted it. I let it idle for a good 15 minutes, no CEL! Truck runs great now, 2k sputter is gone.
Figured I'd give everyone a heads up on this factory defect I found in the wiring harness. There's no telling what kind of issues were caused by this.
The day I brought it home, had issues with the vacuum line from the intake manifold to brake booster. I replaced it with new 5/8" heater hose and went about my business. Well, this interfered with the action of the Charge Motion Control rods and caused them to stick open. Thus, 500 - 3,600rpm, it was a gutless turd.
I also had a CEL throw the next day. Used a scan tool, said that "System Couldn't Complete Self Test". Awesome, very specific OBDII...
I drove it like this for a while, not really concerned. I'd reset the ECU and the code would clear until I got on it really hard, then it might/might not come on. When it did, fuel mileage sucked so I assumed I was in a limp mode.
About a week ago, the truck started stalling on takeoff and jerking when up to speed between 1,800 & 2,000rpm.
I dove into it today. I ordered a new throttle body several days ago, it came in today. I pulled the intake manifold out and re-routed the vacuum line to prevent interference with the CMCV system. While the intake manifold was off, I cleaned the filthy butterflies with a carb cleaner.
Upon reinstallation, I was tracing the wiring harness on the back of the motor and found this...
Not sure if this is the Coolant Temp Sensor or the Knock Sensor lead, but the wires were twisted from the factory and had began to touch and short.
Fixed the short, reinstalled the manifold in a 10 bolt 3 stage sequence starting at 18inlbs of torque, then going to 50, stopping at 89 inch/pounds. I then installed the new throttle body, primed the fuel pump, reset the ECU and started it up.
Drove it hard for 10 minutes, then shut it off and restarted it. I let it idle for a good 15 minutes, no CEL! Truck runs great now, 2k sputter is gone.
Figured I'd give everyone a heads up on this factory defect I found in the wiring harness. There's no telling what kind of issues were caused by this.