2005 Jeep Grand Cherokee 5.7L Hemi, problem and repair

[jacwjames]

So yesterday I decided to go ahead and pull the passenger side head.  Removing the drivers side gave me an idea what was involved and it went quicker but no by much.  Worked until 5:30PM, a valiant effort but came short. 

There was slightly more room to get at the exhaust manifold to exhaust pipe bolts.  I was able to use my small air grinder for one of the bolts and a reciprocating saw for the other, made much quicker work of it then the other side with a couple decent scratches on my hands. 

The rest went pretty quick but I am now dealing with the darn bracket at the rear of the head for the line going to the HAVC system which runs under the air intake manifold, what a pain.  with a large wiring harness above and other lines really don't have access but I'll get it off one way or another. 

[jacwjames]

Got the bracket removed and was able to lift the head out, which was a challenge.  I ended up taking a chain and bolting it across the top of the engine and standing/crouching above the engine lifted out having to deal with the wiring harness and loose hanging heat guard on the engine.  Both the passenger & drivers side rear exhaust manifold bolts were broke off at the stud that holds the heat shied and the manifold bolt heads were broke off. 

The passenger side lifters and rollers looked good, not signs of wear and moved freely.

The cam shaft lobes all looked good, no significant wear.  So right now I'm leaning toward replacing the cams.  Going to do some more research on the MDS delete option and get advice from my mechanic. 

Someone mentioned that I should drop the oil pan and change the pickup tube.  There is not enough clearance to pull the pan without lifting the motor of the mounts and even if I do that I don't think there is enough room.  Has anyone done this on a ~2005 Jeep Cherokee.  There are cross members that block access from below??

 

[Robert92867]

I admire your persistance. So many options, up to pulling the engine and installing a quality built Long Block. With both heads removed, you have gone past the "minimal repair and sell the toad" stage, and  MDS delete is a foregone conclusion. How do the cylinder bores look? Your Mechanic/Neighbor sounds like your best onsite resource for advice.

[jacwjames]

I don't see any problems with the cylinder bores or valve seats although I haven't removed.  No real signs of problems there. 

I actually got a chance to talk to the mechanic I normally use.   He said that he never liked working on Hemi's and was surprised I had the heads off.  He agreed that if the cam looks good go back with new lifters. I 

Got a chance to talk to the young mechanic he said the same thing, he said if the cam rollers were good and signs of scoring/wear on the cam no need to change.  Good news I guess.  I asked about the MDS complete and he didn't know if I needed to do a new cam or not with MDS delete, he would try and find out. 

Some MDS kits come with new cams, some don't.  I sent an inquiry to one company to find out.   Worse case is I put in the MDS lifters and delete with a tuner. 

[wamcneil]

Ugh. I sure didn’t enjoy going through this process… Then 6-mo after I got it fixed the wife drove it into a culvert and totaled it 😕

I was impressed with how good the motor looked inside after 175k mi. There was still crosshatching in the cylinders.
I hope yours looks that good inside and reassembly goes smoothly!

Edited January 3 by wamcneil

[jacwjames]

Still looking at options for lifters.  Sent some inquiries but no response yet. 

Right now if I can't find a kit that uses the none MDS lifters without having to a new cam I will probably go back with MDS lifters and then just use a tuner to stop the MDS from working.  That way I can always go back to the OEM setup.  This would probably be the cheapest option.

I did take the time to check the valve that was with the lifter that was not working.  It was OK, straight, moved smoothly up and down through the seal.  Contemplating changing all the valve seals. 

I took the time to use my camera to check each of the 16 lobes on the Cam.  Had to get inventive to get a picture while I physically rotated the crank.  I ended up taking one of the long boots off an old coil, slitting it, and putting my small camera in the center.  It was a snug fit.  I simple put this into the lifer hole, got it positioned, and rotated the crank while watching my laptop.   Worked pretty good.  I did all 16 lobes, none had any type of scoring/wear/pitting/or damage.  Based on that I fell I don't have to change the cam. 

So slow progress but still forging ahead. 

[wamcneil]

I replaced the valve seals when I had mine apart too. They come with the gasket set, so why not, right? Mine were pretty loose at 175k.

Why would the cam need to be changed to eliminate MDS? The system is regulated by the ECM via oil pressure selectively collapsing lifters. I'm sure the MDS cam lobes are identical to the non-MDS lobes. Seems like you would need to have a custom tune to disable it one way or the other.

I found that aftermarket lifters were much cheaper than mopar, but I couldn't find any aftermarket that were MDS, so I bought all new factory lifters. Not cheap...

One redneck way to eliminate MDS might be to run a thicker grade of oil... If the computer can't confirm the right oil viscosity it will throw a soft code in the background and disable MDS. I'm not sure that would be reliable, but the guy I bought mine from ran 5w30 oil in it and the MDS system wouldn't start working till I did the first oil change!

Edit: oh wow. Must be new options available now. Just did a quick search and looks like aftermarket MDS lifters are available at a reasonable cost!

If you're planning to eliminate MDS, why not install the MDS lifters and run it like that? If the MDS doesn't give you any more problems, then you're done. If it does still give you problems, then eliminate it with a custom tune

Edited January 4 by wamcneil

[Robert92867]

Jegs sells them, but price is $900 because they include a tuner.  If you know someone who can tweak your ECM parameters you can piece it from the part numbers shown below.

[jacwjames]

Thinking about going back with MDS lifters and just living with it.  The first set last ~150K, I actually put more mile on the Jeep towing it behind my rig vs driving it. 

Still trying to wrap my head around the options. 

[Robert92867]

I think you're right about retaining the MDS feature as the most economical fix.  Several articles I looked at yesterday indicated a different cam profile was needed for non-MDS engines, some saying a diagnostic code (check engine light) would be illuminated if the camshaft was not changed.

[jacwjames]

4 hours ago, Robert92867 said:

I think you're right about retaining the MDS feature as the most economical fix.  Several articles I looked at yesterday indicated a different cam profile was needed for non-MDS engines, some saying a diagnostic code (check engine light) would be illuminated if the camshaft was not changed.

So I spent last night and this morning trying to source a kit for the MDS lifters, gaskets, head bolts etc.  +95% of what is offered is for a NON MDS kit.  Lots more available that go the NON MDS route, that must tell you something, lots of people going with the MDS delete option. 

Amazon kits that fit my jeep all include the cam.

The local auto parts stores, Autozone, Advanced Auto, and O'Reily's, don't offer a complete and/or lifters.  Their lifter sets are well thought of based on the price.  Don' even think about OEM Mopar, a set of lifters would be $3K

So I've contacted a local parts store and he tried to source parts through his normal vendors and none had lifters.  Probably because most people go back with NON MDS lifters and cams. 

So I'll have to decide what options are the best on line without having to break my bank. 

I did  borrowed a tool from my mechanic to look at the valve in the #1 cylinder, took me a while to get the technique down to get it out,  it looked OK, not stuck and the shaft was straight.  So I ordered a set of valve stem seals and will pick up later today and change all the seals.   I'll look at each valve and seat while I change the seals but from what I see all looks good and the compression test was pretty good so I think I'll be fine there. 

So essentially I'm in the process of putting it all back together. 

Edited January 4 by jacwjames

[wamcneil]

Yeah, I was horrified by the cost of new mopar lifters. It was about a year ago, maybe things have changed, but I found sets of 4 new factory lifters on ebay for $200 ea ($800 total). Search for 5038786AD and 5038785AD

It looks like aftermarket may be a good option now. I couldn't find aftermarket MDS lifters at that time. Mine was a 2014. Pretty sure the 5.7 engines were all the same since MDS came on the scene 2004-2021. 

If you're getting a head gasket set, it'll probably include the valve stem seals. The felpro 26423 kit I used did.

Edited January 4 by wamcneil

[Ivan K]

Just a random Google search brings OEM (supposedly) lifter sets on ebay for reasonable cost IMO. Have you actually confirmed that the suspect lifter was bad and not the solenoid valve? I don't really get why the cam would have to be changed for non-MDS since half of the OEM lifters are already solid and the MDS ones act as solid most of the time. Unless they change the power curve to something better than stock.

[jacwjames]

1 hour ago, Ivan K said:

Just a random Google search brings OEM (supposedly) lifter sets on ebay for reasonable cost IMO. Have you actually confirmed that the suspect lifter was bad and not the solenoid valve? I don't really get why the cam would have to be changed for non-MDS since half of the OEM lifters are already solid and the MDS ones act as solid most of the time. Unless they change the power curve to something better than stock.

Yup, one lifter fell apart when I got it out and turned it upside down to look at the roller.  The internal spring was gone or might have fallen out when I turned it over, never saw it, but either way the lifer was bad

[Frank McElroy]

1 hour ago, jacwjames said:

Yup, one lifter fell apart when I got it out and turned it upside down to look at the roller.  The internal spring was gone or might have fallen out when I turned it over, never saw it, but either way the lifer was bad

Interesting that the internal spring (there should be 3 internal springs plus the check valve spring) fell out but the ring keeper is still in place.  I'm wondering if it was only the small check valve and spring fell out.

[jacwjames]

No idea, when I pulled it out it looked fine but eventually when I was looking at all them closer I turned it upside down and the piece fell out, didn't see anything else but I may have missed it.  Either way I don't think it should have done that. 

Hope that was my problem

Too late to turn back now😁

[Ivan K]

Here is a disassembled lifter so you can tell what's missing and hopefully not in the belly of the engine.

[jacwjames]

1 minute ago, Ivan K said:

Here is a disassembled lifter so you can tell what's missing and hopefully not in the belly of the engine.

I'll take a closer look but the rod was still in place, or at least not loose.  The pins on the inner barrel are visible. The circlip is still in place so the other pieces must still be there.  The small end cap came out when I turned it upside down but I have to hold my mouth right to get it back in with the circlip still in place.  My guess is the smaller spring broke and let the inner portion collapse. 

[jacwjames]

So I got a chance to take another look at the failed lifter.  Both circlips were still in place and I have the end cap.  There is no sign of the inner  cylinder and no sign of the spring. 

With the end circlips and end cap still in place don't know how the other pieces escaped, no signs of them.

I inspected the ends of the push rods and rocker arms, no damage there that I can see. 

 

Any ideas what happened to the missing pieces???

 

[Ivan K]

Yes that is strange if only the middle pieces were missing but looking at the picture where you hold the lifter, is the piece between your finger tips the rod seat or does it have a check ball in it? Can't tell.

[Old Soldier]

This is the most interesting read I've seen in ages!!!  Stay with it, Bro! You've got us intrigued! LOL!

[jacwjames]

27 minutes ago, Old Soldier said:

This is the most interesting read I've seen in ages!!!  Stay with it, Bro! You've got us intrigued! LOL!

HA

It's got me loosing a lot of sleep.  The mystery of where the missing piece of the lifter has me concerned.  Thought about this all night, When I first pulled the lifter, externally it looked fine.  

Is it possible that the push rod kept enough pressure on the internal cap and over time pulverized the other inernal pieces into  small enough to disappear into the the bottom of the oil pan???  When I took the video the rocker arm was not moving at all. 

Going to take a closer look at the cam shaft. 

Trying to wrap my feeble head around this

 

[Frank McElroy]

When the MDS system is energized, oil pressure will push to release the two internal lifter side pins allowing the internal part of the lifter to compress the 3 internal springs in the base of the lifter but they are just not quite strong enough to overcome the strength of the valve lifter.  This keeps the lifter constantly rolling on the camshaft and the intake valve doesn't open.  When the MDS solenoid closes, the two side pins will reengage and the lifter will move the valve.

It's really hard to believe that the check valve and seat for the pushrod is missing with absolutely no wear on the pushrod end.  The only thing I can think of is that the outside wall was worn so much is fell out after you removed it.  It sure is odd.

[jacwjames]

29 minutes ago, Frank McElroy said:

The 3 internal springs in the base of the lifter are just not quite strong enough to overcome the strength of the valve lifter.  This keeps the lifter constantly rolling on the camshaft.  When the MDS solenoid is energized, the oil pressure and the check valve will then build up internal pressure which will be enough to overcome the strength of the valve spring and open the intake valve.

It's really hard to believe that the check valve and seat for the pushrod is missing with absolutely no wear on the pushrod end.  The only thing I can think of is that the outside wall was worn so much is fell out after you removed it.  It sure is odd.

Frank, thanks for the explanation, that means the Lifter roller is in constant contact with the cam and explains why I didn't see any damage.

Attached is a closeup picture of the end cap of the lifter where the push rod sits, I cannot see any where

Also a picture of the inside of the lifter, can't see wear there either. 

With the two circlips in place don't see how the inner cylinder could come out and if that's the case the spring would have been captured also. 

Here's pictures of both ends of the push rods, they all look the same.  Initially I tried to keep them in order but at one point they got jumbled around so can't tell which one was from the failed lifter.

I did several searches on failed lifters, couldn't find one with the same type of failure.

[wamcneil]

2 hours ago, Frank McElroy said:

...When the MDS solenoid is energized, the oil pressure and the check valve will then build up internal pressure which will be enough to overcome the strength of the valve spring and open the intake valve.

I'm not sure if this is a super-important distinction... but that's not how the MDS system works.

Those components on the pushrod end of the lifter are the hydraulic preload system and that's separate from the MDS system. The hydraulic preload section does work with a check valve and oil pressure supplied through the pushrod just like the normal lifters.

But the MDS system acts by separately applying oil pressure around a channel on the outside of the lifter body, from the sides. This separate oil pressure drives in the cross-pins that allow the lifter body to collapse each time the cam lobe tries to open the valve. Then when MDS pressure is removed, the cam rotates to base circle, the lifter extends and the cross-pins snap back into their holes and lock the lifter body in its normal extended position.

If the hydraulic preload system collapses, the engine will still run fine and it won't damage the cam. It just creates a LOT of valve lash and noise. In my case, a normal lifter failed (differently from yours... no parts fell out...). It made a clacking noise that sounded like it was coming from the bottom-end. Sounded more like a rod bearing than a valve-related issue. But the engine still ran fine and as long as you have some reasonable valve lift, there will be no misfires. 

If the MDS section of the lifter somehow failed and the lifter was totally collapsed, that would certainly cause misfires.

W

Edited January 5 by wamcneil