2007 Dodge Ram 1500 5.7 PO340 & PO339
I currently have 126k on my 2007 Dodge Ram 1500 5.7. I just recently did the famous Cam swap with items below;
2023 @ 126k miles
Replaced old 16yr old OEM with Delphia LONG CRANK , start wouldn’t start again after turning off unless I cleared the code. PO440. Now I did replace this without unhooking the battery. I read you may need to replace the Crankshaft sensor too. Before I did that I thought let’s try and replace it with another one incase this one is defective. Went and purchased a Duralast that had instructions in the box that recommended swapping the crankshaft too. I replaced the 1st aftermarket one out with this new Duralast with no change. It started fine, but check engine light every time it started. Didn’t run rough at idle. Would also start after turning it off. Now I replaced the old OWM crankshaft with a new Duralast Cranshaft and it runs even worse like it’s going to die. I’m getting PO339 & PO340.
Any help would be great! I’m stumped!!
2023 @ 126k miles
- Rear shocks
- Mopar Non MDS Lifters
- MDS Block plates
- Melling MC1430 Camshaft
- Melling VS1450 Valve springs
- Lapped all valves
- head gaskets
- Valve cover gaskets
- EGR gasket
- Intake manifold gaskets
- fuel injector rebuild kit “o-rings & filters”
- timing cover gasket
- Cloyes timing chain
- Melling High Volume Oil pump
- oil pan gasket
- Oil pick up tube and o-ring
- TUNER / MDS turn off
- thermostat gasket
- oil change & coolant fill
- 4 : O2 sensors
- Knock sensors
Replaced old 16yr old OEM with Delphia LONG CRANK , start wouldn’t start again after turning off unless I cleared the code. PO440. Now I did replace this without unhooking the battery. I read you may need to replace the Crankshaft sensor too. Before I did that I thought let’s try and replace it with another one incase this one is defective. Went and purchased a Duralast that had instructions in the box that recommended swapping the crankshaft too. I replaced the 1st aftermarket one out with this new Duralast with no change. It started fine, but check engine light every time it started. Didn’t run rough at idle. Would also start after turning it off. Now I replaced the old OWM crankshaft with a new Duralast Cranshaft and it runs even worse like it’s going to die. I’m getting PO339 & PO340.
Any help would be great! I’m stumped!!
Put the stock sensors back in, and run 'em. No point fixing something that ain't broke.
That, and these trucks HATE aftermarket sensors in critical locations. Cam and Crank being right there at the top of the list.
That, and these trucks HATE aftermarket sensors in critical locations. Cam and Crank being right there at the top of the list.
I originally put the old Camshaft back in and same issues. There was no change.
am I missing shooting like a re learn?
am I missing shooting like a re learn?
also new Camshaft sensor has this in it. which is why I tried placing the crankshaft sensor.
Problem fixed!
I started by removing both connections on the battery. I reinstalled the OEM crankshaft sensor that never had an issue to begin with along with the OEM camshaft sensor. Installed battery again and tried starting. LONNNNNGG CRANK and finally fired and ran a little better but check engine light was back on. Only this time it was PO340 camshaft. Cleared codes, and reinstalled the DURALAST camshaft sensor, inspected all wires , double checked trigger wire had 5v. I tried staring and again LONNNNG CRANK but finally fired. It was running fine no misfire symptoms but check engine light was back on with PO340. Turned engine off and cleared codes, and started again and BOOM started right up with no codes. Turned off and on several times with no issues.
I have no idea what caused this and why this same DURALAST camshaft sensor worked today but not yesterday. I will update this thread if I have any other issues. Thanks!!







