[Imcgm]

2007 Dodge Durango 5.7 hemi, I’m getting Dtc code p3449. I’ve read up on it and it sounds like it could be something fairly simple to something super scary! Anyone have any experience with this code, or might give me any direction how best to proceed?

Thanks all,
Mike

 

[Don Fox]

Mike:
From what I can find, that code references problems with the MDS solenoid on cylinder #7. How many miles on your D? This can be a failed or failing solenoid, or use of the improper oil weight. You have been using 5w20 correct? Are you experiencing any other symptoms like engine roughness, etc?

Don

 

[Imcgm]

Hey Don. Thanks for responding. Sounds like exactly what my research turned up, the solenoid in cylinder if ether failing, failed or malfunction or whatever. The truck is just under 150k so it makes sense that things like this would start to fail. My D has been meticulously maintained, I take great pride in my vehicles and I bought it from the original owner who was just as meticulous about maintenance. So assuming it's the solenoid that needs to be replaced, I know those aren't that expensive but I don't have a maintenance manual for this Durango yet so I have no idea what is involved in changing said solenoid.

Thanks again,
Mike

 

[DuRonbo]

Weren't there some issues with water leaking onto the MDS electrical if the windshield cowl warped and allowed water underneath? Seem to remember reading about that for 2nd gens. Might want to take a good look at the wiring near those rear cylinders.

 

[Durangutan]

As I recall, MDS is active on 2,4,6,and 8, not sure where 7 comes in to play. But nonetheless, those stupid MDS solenoids are a pain in the butt. Fortunately I don't live in an area with emissions testing so all it is to me is an annoying CEL.

 

[Don Fox]

Just looked it up. The MDS cylinders are 1,4,6,7. The solenoids are located beneath the intake manifold, so it has to come off to service or replace them. DuRon may have a point about water getting down there. I am sure that such infiltration won't help matters. I think they run $65-$70 each.

Don

 

[Imcgm]

Correct, the solenoids aren't that expensive. Is it a big job to engine manifold off? Looks like the injection rails and such may have to come off, idk the only bad thing about the CEL being on is the auto start doesn't work of there's a check engine light...silly, but it's nice to have.

Oh, and yes I did notice some water on top of the engine.not sure if it's cuz I had just gone through the car wash or the warped cowl. Did anyone come up with a fix for the cowl besides replacing it? A gasket maybe ?

Thanks again all.

Mike

 

[Don Fox]

While I have not done it myself, I have not heard that removing the manifold is too bad. Others who have will hopefully chime in. As far as the cowl thing goes, some have run a bead of silicone or similar along the edge. If you compare the old vs the new cowl though, it is a bit different. The areas around the holes are taller, which would encourage the water to run towards the cowl ends instead of into and down on the engine. I installed the upgraded piece on mine, and it has worked very well.

Don

 

[Durangutan]

Your 07 has the modified cowl unless it was replaced at some point with the older version for some reason. So hopefully if it is not damaged you'll be able to seal it up and be good to go.

 

[Imcgm]

Yeah, I took the air gun to the pooling water to try and determine where it’s coming from or if it’s just old ??‍♂ But thanks everyone. Very helpful...

Mike

 

[Imcgm]

You know what I just noticed guys, the cowl has no rubber gasket or weatherstripping on it where it meets the hood nor does the hood where it closes....anywhere.

I’m assuming I am missing something but since this vehicle is new to me I’m not sure what is supposed to be there, but plastic and metal and metal on metal don’t make a good seal obviously…

 

[keegantimber]

Back to your mds solenoids...the intake isnt too bad to remove. The solenoids can or may be a pain. They are plastic with a couple o rings that seal into an oil gallery supplying oil to lifters. The cast block corrodes around the top of the solenoids making them difficult to extract without breaking. If memory serves me correct there is a check ball valve and small screen in the solenoid...you want to make sure everything comes out of the gallery. If you dont find an issue with wiring and water intrusion you could buy a tuner or have a shop disable the mds system as an alternative fix..

 

[Imcgm]

So if I just have a shop disable the mds I’m running on 8 cyl full time? Anybody done this, how bad does the mpg get? lol

 

[tomk]

on my 07 5.7L GC, using tow mode disables MDS. Dunno if the Durango has that option. you have to hit the button on every start, tho. I don't think it makes much difference mileage-wise.

Mine was popping an MDS solenoid circuit fault, so I just did tow mode until I could get around to dealing with it. It eventually just stopped happening.

 

[DuRonbo]

So if I just have a shop disable the mds I’m running on 8 cyl full time? Anybody done this, how bad does the mpg get? lol

You'll drop a couple of MPG Highway at least.

 

[keegantimber]

So if I just have a shop disable the mds I’m running on 8 cyl full time? Anybody done this, how bad does the mpg get? lol

People have been doing it for years. Do a google search on disable mds. Nephew had a cam a lifters go out of his 2011 Ram. Helped him with the job and went back to reg cam and lifters. He bought Hp Tuner software and a licence for his truck computer. Disabled it himself thru the software. Runs on 8 cyl all the time. Hasnt noticed much if any mpg difference and no codes or engine light.

 

[DuRonbo]

My 2008 Hemi will drop about 2 mpg Highway with MDS disabled at 70 mph. City not so much because MDS doesn't kick in as often. My 2013 Hemi tries to get into MDS as often and as soon as possible.

 

[Imcgm]

I guess mend goal here is to get the check engine light off so my remote start works this winter. It sounds to me like I either replace the sensor or have the whole thing disabled by a garage. Then I can clear the codes and should be all set, just using the tow mode I don't think fixes my overall issue with the cel being on...? Sound about right?

 

[Imcgm]

People have been doing it for years. Do a google search on disable mds. Nephew had a cam a lifters go out of his 2011 Ram. Helped him with the job and went back to reg cam and lifters. He bought Hp Tuner software and a licence for his truck computer. Disabled it himself thru the software. Runs on 8 cyl all the time. Hasnt noticed much if any mpg difference and no codes or engine light.

Yup, that's what I need to know. ty

 

[Imcgm]

My 2008 Hemi will drop about 2 mpg Highway with MDS disabled at 70 mph. City not so much because MDS doesn't kick in as often. My 2013 Hemi tries to get into MDS as often and as soon as possible.

Exactly what I need to know, ty