Engine swap hell

[losemodule]

Hey guys, I need some Dodge brains on this because I’m stuck in limp mode after an engine swap.

Truck: 2011 Ram 1500, 5.7 HEMI
Engine: 2012 5.7 HEMI long block

The story so far:
- After the swap, the truck wouldn’t start at first. I asked my buddy if he put the grounds back, and he made one on the spot. After that, it fired right up.
- First test drives went pretty well. I was even able to hit about 130 km/h.
- But it wouldn’t hold a charge and needed boosts to start.
- Then on later test drives it started dropping into limp mode.
- After that I did a crank/cam relearn. I also swapped the 2012 sensors out and put my original 2011 sensors back in.
- Now the codes for crank/cam correlation cleared, but the truck is still stuck in limp, it’s throwing random misfires, and it sounds lightly diesel-ish all the time.

Where I’m at:
I did this swap with some buddies who are decent mechanics, but they’re not Dodge guys, so now I’m wondering if they missed something with the wiring or grounds. I’m trying to rule out everything before I start tearing the engine down again.

What I need to know:
- Exactly where all the engine grounds go on a 2011 Ram 1500.
- Any other swap-specific info people have run into going 2011 to 2012.
- Has anyone fought through this before with the cam/crank relearn, misfires, diesel-ish sound, and limp mode?

TL;DR: 2011 truck, 2012 HEMI swap. Needed a makeshift ground to even start. Got it running and up to 130 km/h, but needed boosts. Later it started dropping into limp mode. Did a crank/cam relearn and sensor swap, but now it’s stuck in limp with random misfires and sounds like a small diesel. I need the proper ground locations for this truck and any advice on whether my issue sounds ground-related or cam/PCM mismatch.

Thanks in advance — I’m stuck here.

 

[Wild one]

Hey guys, I need some Dodge brains on this because I’m stuck in limp mode after an engine swap.

Truck: 2011 Ram 1500, 5.7 HEMI
Engine: 2012 5.7 HEMI long block

The story so far:
- After the swap, the truck wouldn’t start at first. I asked my buddy if he put the grounds back, and he made one on the spot. After that, it fired right up.
- First test drives went pretty well. I was even able to hit about 130 km/h.
- But it wouldn’t hold a charge and needed boosts to start.
- Then on later test drives it started dropping into limp mode.
- After that I did a crank/cam relearn. I also swapped the 2012 sensors out and put my original 2011 sensors back in.
- Now the codes for crank/cam correlation cleared, but the truck is still stuck in limp, it’s throwing random misfires, and it sounds lightly diesel-ish all the time.

Where I’m at:
I did this swap with some buddies who are decent mechanics, but they’re not Dodge guys, so now I’m wondering if they missed something with the wiring or grounds. I’m trying to rule out everything before I start tearing the engine down again.

What I need to know:
- Exactly where all the engine grounds go on a 2011 Ram 1500.
- Any other swap-specific info people have run into going 2011 to 2012.
- Has anyone fought through this before with the cam/crank relearn, misfires, diesel-ish sound, and limp mode?

TL;DR: 2011 truck, 2012 HEMI swap. Needed a makeshift ground to even start. Got it running and up to 130 km/h, but needed boosts. Later it started dropping into limp mode. Did a crank/cam relearn and sensor swap, but now it’s stuck in limp with random misfires and sounds like a small diesel. I need the proper ground locations for this truck and any advice on whether my issue sounds ground-related or cam/PCM mismatch.

Thanks in advance — I’m stuck here.

Check the grounds on the back side of both heads,alot of times they'll get missed on the reinstall

 

[EdGs]

On my '15, the ground on drivers side head is at the rear, but the pasenger side is in the front.


I think both heads are exactly the same part, the have the same casting numbers. One is naturally reversed, though. I might be wrong about this, just things noticed while my heads are on the bench.

 

[losemodule]

Check the grounds on the back side of both heads,alot of times they'll get missed on the reinstall

And that one goes to the firewall or frame?

 

[Wild one]

And that one goes to the firewall or frame?

On a 2012 Ram 1500 with the 5.7 Hemi, there is a ground strap located at the rear of the cylinder heads that
serves as a chassis-to-engine ground point to ensure stable sensor signals and consistent voltage, though its importance can be debated since most sensors are grounded through the PCM. You should ensure this strap is present, clean, and securely mounted to the cylinder heads, as poor grounding can lead to erratic sensor readings and potential engine issues.
Location and Function

• Position: The ground strap is located at the rear of the cylinder heads, connecting them to the chassis.
• Purpose: It provides an alternative chassis-to-engine ground path, which helps in maintaining stable electrical signals from sensors and other engine components.

Why it's Important

• Sensor Reliability: Stable grounding is crucial for the proper functioning of sensors, like the Accelerator Pedal Position (APP) sensor.
• Preventing Malfunctions: Poor or corroded grounds can cause erratic sensor readings, leading to performance issues and potentially premature component failures.

Maintenance and Inspection

• Regular Checks: Inspect the rear ground strap for signs of corrosion, loosening, or damage.
• Secure Mounting: Ensure that the strap is securely mounted to the cylinder heads.
• Clean Contact Points: Keep the contact points on the engine and chassis clean to maintain consistent voltage and prevent electrical noise.

If You're Having Electrical Issues

• Focus on the Main Ground: While the rear cylinder head ground is a component of the system, also focus on the main engine ground, as it's considered the most critical connection.

 

[Daw14]

You can not have more ground connections than necessary.
With the age of your truck ,every ground is suspect.
Keep an eye on major harness connections, the pins can be pushed from their locked position .
Look at the big harness under the driver side wheel well, it has a large connector that’s prone to crusties.

 

[04fxdwgi]

You can not have more ground connections than necessary.
With the age of your truck ,every ground is suspect.
Keep an eye on major harness connections, the pins can be pushed from their locked position .
Look at the big harness under the driver side wheel well, it has a large connector that’s prone to crusties

You can't have too many grounds. Some of the so called grounds are actually "bonding" cables that help prevent electrolysis between the aluminum and steel components, especially when winter salt is added. Very real problem in modern, multi material vehicles (like boats, too).
Some of those straps also prevent stray RF signals, that mess up the electronics, in some cases.

 

[Wild one]

You can't have too many grounds. Some of the so called grounds are actually "bonding" cables that help prevent electrolysis between the aluminum and steel components, especially when winter salt is added. Very real problem in modern, multi material vehicles (like boats, too).
Some of those straps also prevent stray RF signals, that mess up the electronics, in some cases.

I can attest to that,my truck had more extra grounds run then Carter has pills,lol. I had issues with the tailgate not unlocking when the truck was brand new,and running extra grounds cured that issue,and in the 10 years i owned the truck,it never had any electrical issues except one that was self caused when i wasn't careful reconnecting the throttle body and slightly dislodged one of the pins in the connector