2007 Dodge ram runs rough at 1000-1500 rpm
2007 Dodge ram runs rough at 1000-1500 rpm
Hi. So I had an issue about a year ago where my engine began running rough. I did everything I could but I couldn't find a fix. My 4th cylinder was misfiring but it wasn't my spark or fuel. It turned out to be a bad MDS solenoid. After I replaced it, it seemingly fixed the issue but after about 2 months my truck began to run rough at around 1000 to 1500 rpm and even seems to try and drop down to that rpm range and speeds between 35 to 65. When I change my oil it seems to fix the issue temporarily but I after around a couple hundred miles it begins to run rough again
Professional
Joined: Oct 2018
Posts: 157
Likes: 3
From: New Hampshire(NH)
Now the oil change is a very interesting part. What oil do you run I know my truck yells at me (Code) for 5W30 and is happy at 5W20 but I'm a 1500 and I don't do much towing or hard duty work only rarely. You mentioned MDS and MDS runs off oil pressure last I remember (or is effected by it) so what it seems to me is your MDS is acting up and your oil is related.
I presume you change your filter every oil change unless its a high mileage one so it's likely very clean. Engage tow haul mode and see if the same behaves, then try it again in OD and see if it also does the same. Either of these modes disable MDS and if it runs better then it would suggest your MDS is the problem.
Alternatively if you really want to test get yourself a Posi-Tap and find your MDS wire on the ecu on the passenger side and tap off it with an LED in the cabin (no relay just ground needed). This allows us to monitor the MDS in real time, is it a solid light, does it go out when you accelerate hard, does it even come on at all? This allows us to atleast indirectly take a look at, read codes if possible as well i know our trucks only trigger a light for emission or related codes in my experience (even if your fuel pump dies it wont trigger an engine on CEL, you can guess how i know). https://dodgeforum.com/forum/3rd-gen...l#&gid=1&pid=1 is a good post for this MDS light method but do note i'd consider it advanced.
but i highly recommend just doing code and tow/haul tests and etc.
I presume you change your filter every oil change unless its a high mileage one so it's likely very clean. Engage tow haul mode and see if the same behaves, then try it again in OD and see if it also does the same. Either of these modes disable MDS and if it runs better then it would suggest your MDS is the problem.
Alternatively if you really want to test get yourself a Posi-Tap and find your MDS wire on the ecu on the passenger side and tap off it with an LED in the cabin (no relay just ground needed). This allows us to monitor the MDS in real time, is it a solid light, does it go out when you accelerate hard, does it even come on at all? This allows us to atleast indirectly take a look at, read codes if possible as well i know our trucks only trigger a light for emission or related codes in my experience (even if your fuel pump dies it wont trigger an engine on CEL, you can guess how i know). https://dodgeforum.com/forum/3rd-gen...l#&gid=1&pid=1 is a good post for this MDS light method but do note i'd consider it advanced.
but i highly recommend just doing code and tow/haul tests and etc.