2005 Jeep Grand Cherokee 5.7L Hemi, problem and repair

[jacwjames]

OK, instead of beating my head against the wall I went over and talked to the young mechanic.

He looked at the lifter and said that the inner piece is still in the lifter, it is just at the lower position.  When I push against it there is a little spring action.  The pins are not locked in.  I'm going try and get it apart and see if the spring is still intact or broken.  I'd like to confirm just to know what actually caused the failure. 

The first thing I did when I started working on it ~2.5 weeks ago was to replace the MDS solenoids, I would hope I can rule that out as the cause.  I took if for a ~40 mile drive and it ran fine but the then acted up when I changed the oil.

[wamcneil]

Regarding "The pins are not locked in."

There's a subtlety that I left out of the MDS explanation. Those pins don't actually lock into the holes. That part inside is the lifter is free to rotate. The holes let the oil pressure in, and the pins actually lock into a groove around the inside of the lifter body. That can be seen in the cutaway that Frank posted yesterday.

 

Edited January 5 by wamcneil

[cbr046]

I was pretty lost on the "why" MDS lifter and how it worked.  The "why" seems to be 4 vs 8 cyl operation for fuel economy, but this helped the how . . . . (not sure if yours is a Gen III but have to "assume" it's similar). 

- bob

 

[Bobkat11208]

Following this and, NGL, two thoughts come up (okay 3 😀). First, never gonna get me a hemi. Second, I truly miss the days when the engine simply went up and down and the wheels went round and round and it didn’t take YouTube to figure something out. And finally, I’m jealous you even have a place to work on this! I’ve got a 2car attached storage shed. #firstworldproblems 😂

Edited January 5 by Bobkat11208

[jacwjames]

1 hour ago, Bobkat11208 said:

Following this and, NGL, two thoughts come up (okay 3 😀). First, never gonna get me a hemi. Second, I truly miss the days when the engine simply went up and down and the wheels went round and round and it didn’t take YouTube to figure something out. And finally, I’m jealous you even have a place to work on this! I’ve got a 2car attached storage shed. #firstworldproblems 😂

X2 on the Hemi but I'd expand it to a MDS type system in general, too complicated and opportunities for failure.  But the reality is all vehicles are way too complicated and without the correct tools and diagnostic equipment the average Joe (me for instance) is pretty much lost. 

 

I actually wanted to start working on this back in early Nov but my wife got in a Crafty Mood and had the garage full of stuff she was working on. 

I had plans on putting a car lift in my 40X50' garage but haven't gotten around to it, it's on my wish list and will eventually get it done. 

 

[jacwjames]

So I'm cleaning up all the parts getting ready to go back together. 

I received the valve stem seals and replaced the old ones.  None of the local auto parts stores had a tool that would work on my Hemi.  I borrowed an old style tool from my mechanic.  Was trial and error on how to use.  I improvised a small block of wood onto the end along with a ball of paper towel that helped keep it positioned on the valve while I depressed the spring retainer.  Struggled with the first couple, even lost one of the tapered spring retainers, had to buy some at O'Reily's.  Once I got it adjusted right it worked pretty good and I could change one out in ~4-5 minutes. 

So waiting on more parts but still have clean up the block but things are moving forward.  

 

[Robert92867]

Research the do's and dont's of cleaning aluminum and cast iron combustion surfaces, but especially with aluminum,  It's very easy to remove too much metal, even with a scotchbrite pad.  I went with razor blades, then a light touch with carbide scrapers, and frequent checks with a straight edge and feeler gauge. Don't try to achieve a mirror finish, just enough cleaning to pass  < .003 feeler gauge in 4 directions. Keep the cylinder bores coated with oil, don't let rust get a hold on bare iron bores.  Get a strong magnifier on the valve seat surfaces. and valve surfaces.  You're at a critical point in reassembly.  I'm an amateur, and I would have ruined my Cummins engine had it not been for Youtube videos. I hope some real mechanics chime in on this subject.

[jacwjames]

So it's been two weeks since my last post on my Jeep Hemi problem,

I've actually had several PM's with Rikadoo>>>thanks a bunch Rik!!

But thought I'd give an update

I ordered and received all the parts to put it all back together.  What I did

1. Replaced all the MDS solenoids.
2. Replaced the valve seals
3. Installed the new lifters both sides
4. Replaced both head gaskets and installed the heads
5. Put the rods and rocker arm assemblies back in
6. New valve cover gaskets
7. Put the steering pump back on and belt on. 
8. EGR valve
9. Put the coils and plug wires back in and a whole new set of plugs.
10. Cleaned the throttle body
11. Cleaned the MAF
12. Cleaned the PVC
13. Connected all with wiring harnesses and vacuum lines

It started right up but runs rough but does not throw any codes.  I pulled the valve covers again and found the #4 lifter not working, I checked the top of the piston and lifter with a bore scope, all looked good.   So I redid all the rods on that side to make sure they were all seated properly.  Had my wife turn over the engine to confirm all the lifters were working and they were.  Called it quits last night.  This AM had my wife turn the engine over again, all lifters were working.

So I put the valve covers, coils, plug wires etc back on.  Started it up still rounding rough again, no codes.

So I pulled the passenger side valve cover again (getting pretty good at it) and had my wife turn the engine over and #4 lifter not working again. 

Now wondering if it may be a PCM issue, I watched on video that ended up being the problem. 

 

Does anyone have any suggestions on what might be the cause??  Almost ready to throw in the towel. 

[Ivan K]

Can you tap into the solenoid power to see if it is actuated, compared to an other? That could give an idea of the PCM suspicion. 

[wamcneil]

How long did you let it run? Maybe that one lifter is just taking a long time to pump up? 

I remember having to go back and re-seat one of the pushrods that got lodged up on the side of the lifter. But that was obvious before I got the valve covers back on. 

Regardless of why a valve isn't opening, if a valve isn't opening at all it should throw a misfire CEL very quickly. If the hydraulic preload isn't full, it'll still open the valve some significant amount.

Sounds to me like the lifter just hasn't filled with oil yet? Seems pretty unlikely to me that your PCM developed a new problem while you had the engine torn apart.

 

Edited January 22 by wamcneil

[jacwjames]

Ivan>> difficult to get to the MDS solenoids and/or harness,  Would have to take air manifold off.  From what I've read the MDS should be off and not activating the solenoids. 

Wamcneil>>> When I first started it I had to back it out of the garage to let all the oil burn off the manifolds.  I parked it outside and let it idle for ~1/2 hour.  Then drove it off and on as I've been battling try to find the issue.  This AM when I had my wife turn it over and the #4 lifter was working there was plenty of oil flowing out of the rods and rocker arms. 

When I first started it up it actually idled pretty good but as soon as I took it out for a drive it would run rough. 

I'll take another look at it tomorrow, going to pull the rocker arm assembly back off and start from scratch on the passenger side.  Getting pretty good at that also. 

Luckily I've got plenty of time and other vehicles to drive.  We got ~8" of snow last week and it's been cold in E TN and the snow got packed down on the roads and then we had freezing rain on top of that.  Roads are like a skating ring, but my 89 GMC Suburban gets around OK but I've come close to going of the back roads several times.  It ain't the going but the woahing😀

[cbr046]

5 minutes ago, jacwjames said:

It ain't the going but the woahing😀

 🤣🤣🤣

- b

[Ivan K]

If the MDS solenoid valve was being open by erroneous signal from the PCM, it should effect both intake and exhaust valves,  right? As I understand, that's not what you observed so probably not the PCMs fault. Still could be confirmed at the PCM connector side if not accessible at the solenoid?

[jacwjames]

12 hours ago, Ivan K said:

If the MDS solenoid valve was being open by erroneous signal from the PCM, it should effect both intake and exhaust valves,  right? As I understand, that's not what you observed so probably not the PCMs fault. Still could be confirmed at the PCM connector side if not accessible at the solenoid?

Good point Ivan, Seems logical

I've got set of intake push rods on order and will replace them to see if that might be the problem. 

All the push rods looked good, no signs of wear.  I made sure they weren't stopped up and soaked them in oil before install.  But having intermittent trouble with one is odd.

I called my mechanic yesterday and he's stumped (and glad he isn't working on the darn thing).  Going to try and also talk to the young mechanic next door and see if he has a clue and whether he has a scanner that might better diagnose the problem. 

[Frank Bergamo]

Have you considered low oil pressure, or wrong oil viscosity. Both are critical to proper operation of hydraulic lifters. Seems to me all the mechanical and electrical pieces have bee addressed. Do you have an oil pressure gauge or a light? Might try a mechanical gauge if only a light, to verify good oil pressure. Hope this helps.

[jacwjames]

1 hour ago, Frank Bergamo said:

Have you considered low oil pressure, or wrong oil viscosity. Both are critical to proper operation of hydraulic lifters. Seems to me all the mechanical and electrical pieces have bee addressed. Do you have an oil pressure gauge or a light? Might try a mechanical gauge if only a light, to verify good oil pressure. Hope this helps.

Thanks for the response.

Yes, I thought about oil pressure, no light on dash but it is a dummy light, no gauge.  No fault code to indicate low oil pressure. 

Recommended oil weight is 5W20, and I used full synthetic this time when I changed oil after putting everything back together.   From what I read most people recommend full synthetic for MDS systems. 

When I was having my wife turn the engine over I did look for oil flow from each of the push rods and there was a noticeable amount.  All other lifters were working, the #4 is in the middle. 

[jacwjames]

So hopefully this is my last update to my problem and final solution.

I took the Jeep over to the young mechanic next door and he tried to use his scanner but it was running so bad it wouldn't read, he said that's why it wasn't throwing codes.  He said that the lifters I bought were the problem, he doesn't recommend buying after market lifters unless they are from a place like Summit Racing etc. 

So after trying everything I finally decided to pull the lifters and send them back for a refund.  Ordered a set of Mopar lifters and got the last week and started going back with everything.  Cleaned the lifters with mineral spirits and soaked them in oil for a day and installed, went back with new gaskets and headbolts.  I screwed up when I was putting in the exhaust rocker arm assembly on the passenger side, I first grabbed the intake and started to go back using the intake side but couldn't get it to tighten down, then realized the problem but got everything back together and right now, this minute the engine is running top notch.  Sounds good, quite smooth idle, and fast fast fast acceleration.  Not sure how long it will last but right now it is finally fixed.

 

So hindsight being 20/20, I should have listened to my brother from the beginning and do a compression test.  This would have told me right away which cylinder I was having trouble with, then a quick check with the valve cover off would have shown me the lifter was working.  I wasted +3 WEEKS grabbing at straws trying to avoid having to change the lifters (which in my gut and internet searches was the root cause of the problem). 

Most importantly I should have listened to others who recommended buying good lifters to start with.

But in the end the job wasn't that bad considering the tight quarters I had to work in.   Learned some new stuff and in the future won't be afraid to dive right in. 

It also gave me an opportunity to buy some tools I needed and should have had in my tool box. 

• I bought a stubby 1/4" air ratchet that was very handy for tight quarters
• and longer 3/8" drive ratchet. 
• Finally got some organizers for my sockets which makes finding the correct one quick. 
• Bought an extendable magnet retriever
• Bought a good rechargeable LED work light with magnet base. 

 

 

[wamcneil]

Wow. I would think that aftermarket lifters might have long-term durability problems, but not immediately defective, engine-not-running issues!

What an ordeal. I'm glad you've got it running right now!

[jacwjames]

2 hours ago, wamcneil said:

Wow. I would think that aftermarket lifters might have long-term durability problems, but not immediately defective, engine-not-running issues!

What an ordeal. I'm glad you've got it running right now!

I had been seeking advice from the mechanic I normally use and he said he'd been talking to another mechanic about a similar problem on a Chevy motor, he had just replaced lifters and had the same problem and solution, one of the new lifters was not working. 

I did a quick search on "new lifter bad" and came up with lots of hits. 

Hopefully I've got it fixed and am going to drive the heck out if over the next 2 months as my wife has a long trip planned in May and needs to pull the Jeep to use.