2000 Dodge ram 1500 3.9 liter v6 misfire codes
#1
02-13-2014, 07:08 PM
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#2
02-13-2014, 07:40 PM
Many people have reported replacing all these and still get misfire codes.
Assuming you've cleared all codes after installing the new parts and they are recurring:
Double-check your spark plug wire routing. You may be aware of this already but they must be carefully routed so nothing overlaps or lays on any engine part.
Check that the coil is properly grounded. Many reports of people replacing the coil but not properly cleaning the coil mounting bracket/bolts resulting in poor coil ground and this will result in weak spark due to voltage drop.
If none of that works then the cylinder heads may be cracked as that is a known issue with the 3.9L Magnum engine. A compression check of all cylinders should verify this.
Assuming you've cleared all codes after installing the new parts and they are recurring:
Double-check your spark plug wire routing. You may be aware of this already but they must be carefully routed so nothing overlaps or lays on any engine part.
Check that the coil is properly grounded. Many reports of people replacing the coil but not properly cleaning the coil mounting bracket/bolts resulting in poor coil ground and this will result in weak spark due to voltage drop.
If none of that works then the cylinder heads may be cracked as that is a known issue with the 3.9L Magnum engine. A compression check of all cylinders should verify this.
Last edited by blackvan; 02-13-2014 at 08:01 PM.
#3
02-13-2014, 10:39 PM
Many people have reported replacing all these and still get misfire codes.
Assuming you've cleared all codes after installing the new parts and they are recurring:
Double-check your spark plug wire routing. You may be aware of this already but they must be carefully routed so nothing overlaps or lays on any engine part.
Check that the coil is properly grounded. Many reports of people replacing the coil but not properly cleaning the coil mounting bracket/bolts resulting in poor coil ground and this will result in weak spark due to voltage drop.
If none of that works then the cylinder heads may be cracked as that is a known issue with the 3.9L Magnum engine. A compression check of all cylinders should verify this.
Assuming you've cleared all codes after installing the new parts and they are recurring:
Double-check your spark plug wire routing. You may be aware of this already but they must be carefully routed so nothing overlaps or lays on any engine part.
Check that the coil is properly grounded. Many reports of people replacing the coil but not properly cleaning the coil mounting bracket/bolts resulting in poor coil ground and this will result in weak spark due to voltage drop.
If none of that works then the cylinder heads may be cracked as that is a known issue with the 3.9L Magnum engine. A compression check of all cylinders should verify this.
I ended up replacing the heads - no more codes. Until you 'burn' the plug wires after 18 months after doing them
