Jeep 5.7 HEMI MDS control

CraigE

Sr. Member
Joined
Aug 27, 2007
Messages
194
Points
18
Make
Jeep
Model
Grand Cherokee
Year
2009
Miles
113
Engine
5.7 HEMI with MDS cylinder deactivation
Anyone familiar with the cylinder deactivation in the HJemi 5.7 liter, I have one that is deactivating at idle 3 of the 4 cylinders that are controlled. Immediately sets 1414


P1416 and P1417. I have spark on these cylinders at start then it shuts off. only cylinder 1 seems to be active during idle . along with the other 4 non controlled cylinders. Very frustrating. I changed all 4 MDS solenoids today and at least I got power back off of idle.
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
11,274
Points
63
Location
St-Hyacinthe, Quebec, Canada
You might want to go see a few tags on these google some stuff.

I am going to give this a hit, waiting for late might chocalate milk to warm

So since I want to start this right, cylinder 7 is deactivating and also 6, ok,

My first advice, use some rinse agent first for engine oil, if need be, might have to change oil filter twice also, but hey it better than cylinder shutdown when you dont want it.

Something like risoline or valvoline of anything that is a rinse agent is key here, or you may kill engine. If your mds sols look like this, may need two good runs when they are declogged,. But if they remotely look like this pictures, soak in some varnish remover or similar. Then try again.

mds.jpg
 

nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
11,274
Points
63
Location
St-Hyacinthe, Quebec, Canada
I think I saw a few tsb for that, but when I see those codes, at once together, and on same bank, oil restriction is first that should be in your mind. That is my advice. I really know there is a tech bullitien on this, just not sure where to find or if it made it to print yet for general public.

Hope that helps, I will check some databases, and see if I cant get that tsb I think I saw and give it you you. Yeah, old tsb, just soak, they say carb cleaner mopar part number whatever, but as the other nick say, seafoam should do the trick.

I just soak em that way, when the get soggy on the oil buildup, look at screens, if they r intact and switch, good to go, but for sure, these mds engines need a bit more of care than thier gdi counterparts.

8000km oil changes with spec oil, golden, forgot that, well yeah, this is what you get, normally the 5.7s are very lenient, not these ones. They quit quick when cylinder shutdown due to oil restriction

If the gunk is real bad, you may need new lifters or soak those in tranny fluid like when we used to race a 1/4 with real cars.

I found some stuff that may help also to find how to check if actually both the drivers fails, but usually, follow this tech bulliten.

Step six of chart will explain what I am trying to say.
 

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nickb2

Wrench. Diagnostic Tech.
Joined
Nov 22, 2008
Messages
11,274
Points
63
Location
St-Hyacinthe, Quebec, Canada
it is easier for me to read than to write, so on this, hope all is well in your area and zombies are not flying about like chickens with head cut off.

Black humour is always demise in situ like this, it takes the bite out of reality. ;) :fixed:

 

CraigE

Sr. Member
Joined
Aug 27, 2007
Messages
194
Points
18
Well I got lucky. The way this sounded yesterday I thought I had bad lifters if cam. After replacing all 4 MDS solenoids the codes 1414 1416 1417 kept returning.

Today I disconnected the battery for 30 minutes and when I started it everything was fine. Runs like a top. Go figure?? Thanks.

Engine looks clean inside.
 
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