2005 Jeep Grand Cherokee 5.7L Hemi, problem and repair

[jacwjames]

FWIW,

So back in Oct during my trip from H#$@ I reported on a problem I had with my Jeep. Check engine light came on Jeep ran rough, threw a code having to do with random misfires.  I had changed plugs and wires bu that didn't fix the problems.  Internet searches suggest might be a problem with the solenoids that control oil to lifters for the variable displacement system that drops four cylinders out of the firing order to improve mpg.  

FINALLY got a chance to pull it into the garage and dove in.  Had to remove the air intake manifold meaning had to disconnect the plug and coil connectors, fuel injector harnesses, and all the various sensors and tubing.  What a pain.  Tight quarters and bits and pieces to deal with.  Got the Air Manifold out, took me ~5 hours!

Then had to remove each of the solenoids one by one.  I watched multiple videos and all pretty much showing that getting out the solenoids in one piece was pretty much impossible.  Best thing to do is snap the coil off, use a large  lag screw down the center of the remaining piece and then used a claw hammer out with the claw widened to go on the lag bolt, and popped each one out easy peasy.  Got all 4 of the solenoid out and new ones installed one at a time.  Put new gaskets in the air intake manifold and cleaned the matting surfaces and got it back installed.  Then went through and reattached all the wiring harnesses and tubing. 

I worked pretty efficiently, given my fat hands and fingers which don't go well in tight quarter. 

Anyway, got everything back together and fired up the Jeep.  Still a check engine light on so pulled out the code reader and it showed a code dealing with ignition wiring.  Went back and checked, left one of the ignition coil wires off.  Put it back on and tried it again >>> All Good.  took it for a test drive and it worked good. 

So I spent ~$250 in parts and ~10 hours of my time.  No idea what shop would have charged but I'm sure it would have been substantially more.

 

 

Edited December 21, 2023 by jacwjames

[jacwjames]

I spoke too soon, darn it🤬

Yesterday morning I took my Jeep for a longer drive, initially I it ran a little rough but it cleared up and drove good.  Good acceleration and power, no problems.  I was feeling good.  Decided to go ahead and change oil and filter, all good there.

Decided to take it for another drive and almost immediately it started to stumble and threw a CEL.  Pulled out my code reader and it brought up the codes for multiple misfires on #4 & #7 cylinder.  I did a quick check and didn't see any real issues. 

So now I'm at a loss. 

Been doing searches and potential causes, since the Jeep ran good for ~40 miles I would think that rules out a lifter problem and I had already changed plug and wires and the four MDS solenoids.  Checked all the wiring that I could get my hands on. Next step is to check coils.  May even buy one ~$50 and swap out one on either #4 or 7 cylinder.  

Called the mechanic I use for stuff, he doesn't have the diagnostic capability but will call a friend that does and will make arrangement for me to take my Jeep next week and put it on the computer and maybe able to find the problem. 

Anyone have any suggestions.

[FishAR]

If it was a Ford I would say coil packs.

Have no experience with jeeps.

[jacwjames]

22 minutes ago, FishAR said:

If it was a Ford I would say coil packs.

Have no experience with jeeps.

Thinking the same thing.  Hemi has 2 plugs per cylinder and the #4 & 7 are connected together 

Going to swap coil pack on #4 cylinder, quick and cheap test. 

[Ivan K]

Hope you find it in the ignition circuits. I had to replace a computer once that caused misfire on a single cylinder after warm up on a Dodge truck. It didn't have a hemi like yours but that wouldn't make a difference.

[jacwjames]

1 hour ago, Ivan K said:

Hope you find it in the ignition circuits. I had to replace a computer once that caused misfire on a single cylinder after warm up on a Dodge truck. It didn't have a hemi like yours but that wouldn't make a difference.

Yup, computer is a possibility, I have watched dozens of videos on possible fixes.  One of them the mechanic had the right diagnostic equipment to test pretty much everything, and he did, but never could find the cause.  Out of desperation he bought a new PCM and had it programmed BINGO that was the problem. 

Going take a look at the two coils the misfires are coming from, I could easily buy 2 and see if that fixes it, ~ $90, or I could buy a set of 6 for $270 and just change them all.   I can do this myself.

The 2005 Jeep has 150K miles so it may be time anyway.  That way I'd have all new wires, plugs, coils.  Hate throwing money at a problem but without the required diagnostic tools I'm shooting in the dark. 

 

[jacwjames]

Well, still no joy.

Installed a set of coils today, similar symptoms "multiple misfires".  Initially is said #4 & 7 misfires.  Then #6 cylinder started with misfires.  Did some more checking and now it is down to #6 misfires.  Still runs rough. 

I did check the resistance of most of the fuel injectors, all with in spec.

I did play with my cheap code reader, it actually does have some detail showing misfire count on each cylinder. 

I'm pretty much at a dead end.  After Christmas I'm going to take it to a shop with diagnostic capability.  Since I've already changed the DMS solenoids, plugs, wires, and ignition coils it might be easier for them to diagnose, all the simple things already done.

 

[JacobA]

Are you using OEM plugs, they are very cheap so most go for a “better or different plug” lots of issues posted about misfires resulting in codes. Maybe worth a try I got mine from rock auto for under 20 bucks for all 16 and got two extras just in case I got a damaged or bad one. I have a 08 commander 5.7 same engine I believe also drops out 4 cylinders. I didn’t use OEM coil packs as there doesn’t seem to be real picky with those.

[jacwjames]

I went with NGK plugs, not the fancy ones, I read that Hemi's don't like fancy plugs.  

I stopped at my neighbors for a minute after I drove it an it was acting up.  While listening to it you could hear it running rough.  I pulled the plug wires off some of the coil while it was running, the were putting out the juice with sparks flying.  When I pulled the #6 wire off and plugged it back in the engine settled down and sounded pretty good at idle.  But as soon as I started to drive it started acting up again. 

[Rikadoo]

hey so James, it looks as though there are 8 coils, and your getting a misfire for 4 & 7 NOT 7 & 4 correct? So my question is can it set a 7 & 4 code? if so then go to #4 coil and monitor the pulse feeding that coil, in my "diagnostic tool box" I have a LED test light that is powered with 12vdc, which runs a "program" that tells you when touching the pointed tip to a circuit it will show a green light for - or red light for + and it does it very fast, so when looking for a issue like yours I use a back probe into the offending circuit and then connect it to the tip of the test light, and with the engine running you should see the led lights dither from red to green as the circuit open and close. now as its doing its on/off, on/off, on/off I gently move the wire harness back and forth (the actual name for this procedure is a wiggle test) during that time your looking to see if you can interrupt that on/off rhythm if it does then you have a broken or shorted wire. I have had bad crimps right at the connector where the wire is crimped, I also have found corrosion in multi wire plugs in that harness, sometimes just unplugging then reconnecting them will make it get a better temporary connection. (in my work I made a choice that ANYTIME I disconnect a plug that before I reconnect them I add "electrical grease" before reassembling.

The next thing I would do is to disconnect the connectors going into the PCM to look for possible green corrosion or broken pin in the place where the wire terminals connect to the pin in the cavity. 

another tactic I employ is like say I think I have a injector that is begining to fail or a spark plug or a coil I will swap that part with a known good cylinder and see if the issue jumps to what was the good cylinder. That saves $$$ and you get instant feedback... sometimes

[Ivan K]

Like Rik said if you have the tools. I'd check on fuel pressure on the rail if it seems to move between different cylinders. If it is just cyl #6, I'd pull the coil wire, plugged into one of your good used coils with used plugs grounded to the block and watch for irregular firing. Noid sets are also pretty cheap to see injector signal irregularity. If so, the signal comes directly from the PCM and I would wiggle/push/clean the connectors, one of them has the firing signal leads and see if it has an effect. If there isn't a crank/cam code, no intake leaks that is. Also cold-hot situation difference could be a pointer. The PCMs go bad sometimes. Of course, a shop with the right scan tool would see all of this and more.

[jacwjames]

Well, getting above my pay grade here.  Plan on doing some more searches but I'm running out of options.  I don't have any fancy equipment and have exhausted all the easy stuff.  Haven't looked at the PCM connectors yet, may pull them one by one and take a look but other then visual can't go beyond that. 

[jacwjames]

So initially the codes indicated multiple misfires #4 & #7 cylinders.   When I changed the plugs and wires ( I was in UT at the time Oct) that stayed the same.  #1, 4, 6, 7 are all controlled by the MDS soleoids, so I went ahead and changed all 4 of these this last week.   Just getting to these is a job to get the air manifold off so bit the bullet and changed all 4. 

After I changed the MDS solenoids it ran good for ~40 miles.  Started to do my happy dance.

Then I changed the oil and it went right back to running rough showing the same two cylinder misfires, #4 & #7.  These two plug wires are attached to the same coils.  Seemed possible that one of the coils was bad.  I have 150K miles on the Jeep and all the coils are original so I decided to go ahead and change all 8. 

Initially, when driving it did the same thing sowing #4 & #7 misfires, took it on multiple short drives.  Now using my OBD code reader it is show misfire on  only  #6 cylinder. 

I did check the ohms on 4,6,7 injectors and a couple others, all are within range.  I pulled the plugs on these cylinders and checked (they were essentially new) just to check gap and appearance, no issues there. 

Going to pull the harness off the ECM and visually inspect. 

Maybe do some wiggle testing as suggested, yesterday when I was at my neighbors with the engine running I pulled the wires off 2, 4, 6 cylinders, plenty of spark.  When I pulled the wire off #6 and reinstalled the engine calmed right down, sounded pretty good (kind of rules out lifter issue).  Now the engine is running rough and consistantly shows misfires on #6 cylider. 

 

But getting close to Christmas so may have to take a break.  And be thankful I have the time to work on this and 3 other vehicles to drive if needed. 

May be time for Santa to bring me a new TOAD😁

 

 

Edited December 24, 2023 by jacwjames

[jacwjames]

So I inspected as much of the wiring harness that I could get my hands on.  I pulled the wire plugs off the ECM and inspected and didn't find any signs of corrosion, I did spray both sides with electric clean.  I also took battery cables off and did a hard reset of the electronics. 

Took a test drive still threw a code, but it's a moving target.  Now I'm getting either the P0300/P0306 which is misfire code and also getting P1416 code which is #6 Reactivation Code, which has to do with MDS system.  Could be a lifter getting hung up, there are some pretty good videos showing the problem.  Going to watch some videos on how the repair, which involves removing the head.  At least this is on the passenger side which has more room to work.   I'll wait until Tuesday and see if I can get the diagnostics run first.  If not it's full steam ahead.  🤬

[Rikadoo]

So James one more thing, if you think it may be a lifter, a old trick we did back in the day is to run a quart of ATF (automatic transmission fluid) in the engine oil. ATF is a detergent type oil and will clean a lot of things like oil passages an such… You do need to know that if your engine has high milage (like over 100k) it is non discriminatory on where it cleans, like all the crud behind the oil control rings on the pistons, which can make your engine start using oil. 
When you pulled the plugs out, did you look at the porcelain on the outside for hairline cracks? 
FYI many years of Ford pcm’s operating strategys were that after so many misfires which set a code on a specific cyl, it would turn off the injectors on that cyl during that run cycle so to keep from pushing fuel in the crankcase which would dilute the oil an also keep unburned fuel out of the cat converter. That clearing the code was the only way to turn it back on.

Software stratigys can be a PITA when trying to diag driveabilty issues, i just spent MANY days on my buddies Can-Am off road UTV🤦‍♂️

Anyway it sounds like your on top of it, just thought i would share a few things, good luck an Merry Christmas

[jacwjames]

Rik,

My Jeep has ~149K miles on it, up until now it's run pretty good with minor repairs required over the last 13 years I've owned it. 

I pulled the valve cover to see if there were any problems, couldn't see any.  I read there was a potential that one of the upper springs could break. 

When I pulled the spark plugs the #6 cylinder's look terrible, they were changed ~700 miles ago when I was in UT.  All the rest of the plugs looked good. 

I have read about using some sort of additives, one that is mentioned in the Jeep Forums is Rislone https://rislone.com/products/engine-treatment/ I was going to get some yesterday but the stores were already closed for Christmas.  But some people suggest it is snake oil. 

So now I have to decide if I want to go in any further or put it back together and try to get it run on the diagnostic and/or put the additive in it and run it. 

[Rikadoo]

James, in my life of a mechanic ANYTHING other than normal lubricants IS snake oil. I have said that to explane this, as someone who has performed comprehensive vehicle repairs, stock quality lubticants are perfect the way they are, yet due to age an design of certain engine familys coupled with lack of “regular” maintenance there is a genuine need for some products (snake oil) however on a daily routine of service it is mearly a way to increase the bottom line of the shop.

Like a tool in your toolbox some of that stuff can work for certain issues, like fuels for instance, gas and diesel how i believe they are designed for the modern engines. Which is double speak for 100% compatable for the types of emmision systems that were being forced to comply with as of the present new model year, yet for many older model systems they will start an run but there far from being able to “perform”.  I could go on abt this but not right now.

Another example Engine lubricants like i said “Quality” lubricants are perfect by themselfs, however its the schedule of regular service intervals that change the equation, face it not knowing the point in which your lubricants break down can only really be determined by analysis, an not by the odometer😳

So for some instances there is a time an place, so your engine for example, lets say your religious in changing your oil at 3k miles that engine will be less challanged than if you ran it 10k miles or more, then god forbid if you have a less than quality oil filter🤦‍♂️ 

So when you said you replaced those solinoids that control the lifters i dont believe you had a specific mis fire only a random one (P0300) where as now your seeing #6 (P0306) coincidence… perhaps. For me i would need more info as to how that system works, but anytime we open a system there is always a chance for “stuff” to get kicked loose only to go “somewhere” as a counter measure my thoughts go towards possably a small something went downstream. That if so how … is the question to remove it. Going “back inside” the engine get $$$, if there is no option we do what me must. However with my experience i found many times “plan B” has offered results. So that what i would be looking at is something with a cleaning ability, eiter a high detergent or something specific (snake oil) some of that stuff states its a two part oil change system, before you drop the oil you pour part “A” in then run the engine around 2K RPM for x amount of time, drain then use part “B” in with the new oil. (Again more bottom line for the shop) or i use in a five qt system 1 Qt of dextron III an run the engine at 1500 or 2k RPM for like 10 minutes. (due to your catalytic converter i would be hesitant to driving on the road) let it set for 30 min then repeate 2 or 3 times. If it cleans it or not running a crankcase overfull can cause issues so, be prepared if you gonna drive it on the road again at least be sure to siphon off 1 quart 1st. Sorry to drag this out like i did, wish i was there to help, let me know how it works out.

 

[jacwjames]

Rik,

I agree with what you are saying.  I have changed oil regularly at 5K miles, sometimes sooner if I'm doing something on the Jeep and it just makes sense to do it.  Last time it was changed I had the Jeep at my mechanic and he was fixing the cooler lines on the transmission, they were weeping and he removed the flexible hose portion and replaced.  When I was over there to see how he was doing I saw the water pump with a small leak so we both agreed good time to change it and since he was that far into stuff I had him service the transmission.  Better to be proactive then broke down on the side of the road. 

 

So this morning I went ahead and pulled the ignition wires off the drivers side, pulled the fuel pump fuse and had my wife turn the engine over to monitor the lifters on the passenger side.  NONE are stuck, rocker arms all traveled the same distance up and down, oil moving through the tops of the lifters.  I took a video so I have it.

Now I'm thinking my original problem back in Oct was the MDS solenoids but didn't change them, not a great place to tear down the top end of the Jeep in a campground.  Wish I did but hindsight if 20/20.  I did put new plugs and wires on but the problem persisted.  Maybe a mistake but I decided to go ahead and drive the jeep to visit the 10 National Parks that I had intended to see. 

So after I changed the MDS solenoids last week it drove good for ~45 minutes, then changed the oil and it started missing again.

So over the weekend when I changed the coils I did not pull the plugs since they were fairly new.  I probably should have.

I pulled all the plugs on the passenger side, the #6 cylinder the plugs are sooted up pretty bad.  So now I'm thinking it was fouled plugs causing a continuation of the missing.  I have added some fuel treatment but the #6 is so bad the engine still misses.  The other plugs looked pretty good

So my plan is to get a couple new plugs for number 6 cylinder.  I'll inspect the driver side plugs and replace as needed.  Put it all back together and try a test drive again.  Maybe I'll get lucky, if not I'll wait until I can get it on a diagnostic computer. 

Edited December 26, 2023 by jacwjames

[jacwjames]

So yesterday I put the new plugs in #6 cylinder.  Bought a new gasket set for the valve cover since it was already off and it definitely needed it, the old gasket was hard and cracked with signs of leakage.  

Had a heck of a time putting the valve cover back on with the new gaskets, close quarter.  First time I had it on and was working on the last bolt when I saw the gasket was sticking out lower rear passenger side.  The engine pretty much fills up the space so working on it isn't easy and I don't have all the specialty tools that most mechanics would have so I have to get creative on getting into tight place.  Hands are scratched/cut 

The bolts that hold the valve cover on have threads extending up past the bolt head which are there to be able to push on wire/hose holders.  Problem is you need a deep well socket to take them off and there were 3 that didn't have the clearance.  I had to use a 8mm wrench, took me forever to get those bolts off.  When I had the valve cover off I cut the extended threads off those bolt and was able to use a standard socket to put them back in. 

Took it for a test drive and it ran much better, engine light flickered on every once in a while.  Stopped and checked for codes several time, some times it would show the P0300 code and some times no stored codes.  So making progress but still not 100%.

Plan today is to pull the plugs on the drivers side.  These were installed back in Oct but I drove the Jeep with the misfires while on my trip.  Hoping there are a couple fowled out causing the problem.  

May go ahead and "borrow" a compression gauge from Autozone and check compression on all cylinders just to make sure that's not a problem. 

[Rikadoo]

James, so when your driving it do you see any smoke coming from exhaust? Your saying the plugs are fouled which i suspect is due to a run rich condition, if your getting smoke… OR if the plugs are still fouling out (black an sooty) you might want start looking at fuel control. Curiosity has me wanting to see what the driver side spark plugs look like, if there sooted up too i would start looking at the common issue “fuel pressure” for example when a fuel pressure regulator 💩the bed it can go 1 of 2 ways, under pressure or over pressure! If its over then everytime the injectors open there will be more fuel per firing than the injector can control. Its strange cause IF the fuel system is running rich your computer should be sending a “rich” code P0174 or simmilar. So when you get that compression gauge, see if they have a fuel pressure gauge an take a look at what its doing. When checking pressures 1st do the key on and record the pressure, then start it an record that, now do a couple “snap throttles” record the highest an the lowest then compare that to the specs.

[jacwjames]

Rik,

Never saw any codes associated with fuel.  Can't remember seeing any black smoke either.

I pulled the plugs on the drivers side.  All looked good except the #1 cylinder, both were fowled out, block soot.  I'll try and find the plugs from #6 cylinder and take a picture and post. 

 

The #1 & #6 cylinders are associated, the plug wires cross from one to the other.  The #1 cylinder is also one of MDS system. 

I'll try and find the plugs and take a picture, they ain't pretty.   Here's the picture, I only found 1 of the #6 cylinder, furthest left, the other two are #1 cylinder. 

I just started the Jeep, no black smoke idling. 

Getting ready to take it for a drive.

 

 

Edited December 27, 2023 by jacwjames

[jacwjames]

Still no joy,

I did check compression, cylinders 2-8 had 125-140 psi, cylinder 1 has ~115 but it takes several tests to get that. 

So tomorrow I am going to pull the valve cover off the drivers side to see what the lifters are doing when the engine is turned over looking at #1 cylinder closely. 

Only thing I haven't looked at is fuel delivery.  No inline filter, it is in the tank.  From what I've read there is no easy way to check fuel pressure on 2005 Hemi.   Injectors can be changed but that shooting in the dark. 

Still waiting to see if I can get diagnostics run on it. 

[Ivan K]

When you have the valve cover off, check the valve springs carefully and that the valves are closed at TDC on that weak cylinder. A broken spring isn't always easily visible but would have caused your symptom for Cyl#1.

[jacwjames]

1 hour ago, Ivan K said:

When you have the valve cover off, check the valve springs carefully and that the valves are closed at TDC on that weak cylinder. A broken spring isn't always easily visible but would have caused your symptom for Cyl#1.

Thanks Ivan. 

I had read about broke springs, didn't think about weak springs but makes sense.  I make sure to look closely. 

 

Seems like I'm chasing my tail and/or playing wackamo with the fault codes. 

But I'll keep digging and trying different things.  I did go ahead and put a bottle of the Rislone in it.  I've read a bunch of posts on the Jeep forums and that is mentioned in quite few posts.  Kind of an act of desperation.   NO GUTS NO GLORY!!!

[jacwjames]

Well, I found the problem.  The #1 intake lifter is stuck.  No movement whats so ever.  Any way to free it up????🤬

Now have to decide if I want to dig deeper and try to fix myself or take it to someone who knows what they are doing.  I have never done a major repair like this.  I am an avid DYI'er but I really don't have a good place to do this work and may not have all the right tools.

What are the chances that the cam is good enough to just replace lifters???  If I could get it running I'd trade it in on another toad.  From what I've been reading the Hemi is pretty notorious for lifter problems, and I've got 150K miles on it.