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Discussion Starter · #1 ·
Missfire issues in cinder 6 and 7 that i can tell.started with cylinder 7..now generic P0300 code.

replaced mds solenoids. changed oil. checked for spark, tested resistance on fuel injectors/listened for activation while engidne running.

bad ticking noise,im assuming push rods.sounds of backfiring possibly in intake manifold.

did add engine restore to "resolve" issues with ticking noise and thats when thigs went bad and started having multiple missfires..engine oil replaced again after that.

no other codes coming up.

2008 grand cherokee limited 5.7 hemi
170,000 miles.

will remove valve covers to check rods but ticking could be other issue.

any ideas what else to check?

can make videos of it running if it would help.

im also wonder if there is fuel getting tk the 2 cylinders as when i pulled plugs in cylinder 7, they were dry and had soot on them.
 

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2006 WK Overland
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Welcome to the forum. How long have you had the vehicle, are there any mods done to it, and what were the circumstances leading up to this (out of the blue, intermittant, after previous maintenance, etc.)? What kind of scanner (cheapo or advanced computerized) are you using? Why did you change the MDS Solenoids? Now multiple cylinders misfiring WITHOUT codes???? Do you have a way (advanced scanner) to see live and freeze frame data? When is the last time the spark plugs were changed (miles) and what brand and type (copper, platinum, iridium, etc.) are in the vehicle? Also, what kind and weight oil (fossil or synthetic) are you using?
 

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Discussion Starter · #3 ·
How long have you had the vehicle?around 2 years

are there any mods done to it?none that i know of.

and what were the circumstances leading up to this (out of the blue, intermittant, after previous maintenance, etc.)? started getting p1714, changed oil on thanksgiving weekend.drove to LA(i live in Phoenix) and back.p1714 came about about, 2 weeks later.realized oil used was 5w30, changed oil again, this time added engine restore..got another code.p1414..changed oil again with 5w20 synth blend..changed crankshaft sensor.replaced all mds solenoids.

What kind of scanner (cheapo or advanced computerized) are you using? cheap 20 dollars from walmart.

Why did you change the MDS Solenoids? research showed its a common issue on thst hemi model and in most cases fixes the issue with the missfire.

Now multiple cylinders misfiring WITHOUT codes?only code inget is P0300

Do you have a way (advanced scanner) to see live and freeze frame data?currently no advance tool nor the money to purchase..coworker has one but is currently out due to having covid.jeep is also 30 miles from location and not able haul it.it is my hauler.

When is the last time the spark plugs were changed (miles) and what brand and type (copper, platinum, iridium, etc.)
are in the vehicle? has not been changed since we got it.when checked.they look good.notnsure of the brand.possibly ngk but will check when i get the chance.was changed at dealership.

what kind and weight oil (fossil or synthetic) are you using?now is 5w20 synthetic blend





Welcome to the forum. How long have you had the vehicle, are there any mods done to it, and what were the circumstances leading up to this (out of the blue, intermittant, after previous maintenance, etc.)? What kind of scanner (cheapo or advanced computerized) are you using? Why did you change the MDS Solenoids? Now multiple cylinders misfiring WITHOUT codes???? Do you have a way (advanced scanner) to see live and freeze frame data? When is the last time the spark plugs were changed (miles) and what brand and type (copper, platinum, iridium, etc.) are in the vehicle? Also, what kind and weight oil (fossil or synthetic) are you using?
 

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This is interesting! The MDS cylinders are 1, 4, 6, and 7, so it would appear that it does have something to do with the MDS or its components. I think, for starters, you'll need to have someone check the engine management system with an advanced computerized diagnostic scanner that can read all modules. Your P1414 DTC definitely indicates a problem with the No. 4 cylinder MDS deactivation. This could, at least in part, have been caused by the wrong oil being put in the engine. I am guessing you didn't have this problem before the wrong oil was put into it??? Anyway, below are some of the possible causes for this code and you'll notice that it does include the lifters and restricted oil passages. Could your engine restore stuff cause carbon or sludge to come loose, I don't know? Only an engine tear down will tell you for sure it this has happened. When you replaced the MDS Solenoids, did you use Mopar ones or aftermarket? I've heard there have been problems with some of the aftermarket ones.

P1414 Possible Causes

(K452) MDS SOLENOID NO.4 CONTROL SHORT TO VOLTAGE
OIL PASSAGES RESTRICTED
LIFTER
MDS SOLENOID NO.4
PCM

I've found it hard to find what I consider "good" information on the P1714 DTC. Below are some of the symptoms and your description of the problem definitely fits what you're experiencing. Below you'll see some of the info. I found describing the types of cylinder deactivation systems used today. So far, I haven't really found a "for sure" solution to what is going on. Also, see the "Possible Solutions" I found on one website.

P1714 Symptoms
  1. Check engine light comes on
  2. Engine stalling or misfiring
  3. Engine performance issues
  4. Car not starting
There are currently two main types of cylinder deactivation used today, depending on the type of engine. P1714 Chrysler Dodge code for the pushrod design which uses solenoids to alter the oil pressure delivered to the lifters. In their collapsed state, the lifters are unable to elevate their companion pushrods under the valve rocker arms, resulting in valves that cannot be actuated and remain closed.

P1714 Possible Solutions

The crankshaft sensor signals the fuel injection computer or the ignition control when the cylinders are firing. This causes the ignition coil to provide a spark and the injector to inject fuel into each cylinder at the right time.If either sensor isn't working correctly, the car will run rough and the engine will be less efficient. In later car models, the car's computer can usually keep the vehicle running, but the engine warning light on the dashboard goes on to warn the driver.

The cam and crank sensor inputs (they must be synchronized with each other using a high end scanner) to the PCM are the two main signals that it uses to determine fuel injector pulse widths and timing. The fuel injected and MDS lifters collapse MUST occur at exactly the same time. If the valve timing is off because of a valve train problem (such as bad a lifter), this would throw everything off and cause misfires, rough running and stalling. Faulty fuel injector(s) and/or PCM could also cause this. Also, since you are now getting valve lifter noise, that possibly indicates a stuck or failing valve lifter, bent push rod, flat cam or ?

What to do, that is the question???? I'd say it's totally your call but, if this did start after the wrong oil was put in it, I think I might try finding a very strong detergent oil that could disolve any contaminants that may be either plugging passages or causing the MDS lifter(s) to not freely move from the activated to deactivated position(s). Be aware that there is a moveable pin in the MDS lifters that activates/deactivates (collapse) the lifters. (I have heard of the pin failing, but very rarely.) Using any engine additives is something I would never normally do, because it could cause more harm than good. I think if you first pull the valve cover(s) (just one would be OK) and look to see if the rocker assembly area is all gunked up, If it is, I wouldn't do it. If it's quite clean as it should be (both of my 5.7's run synthetic oil and are totally and completely clean), then I'd go ahead and try it. You may have to change the oil/filter a couple more times to "flush" any.all of the stuff out. Use your judgement, depending if things improve or not. Be sure to follow the instructions on whatever product you choose to use. You may also want to try using lighter 0W-20 weight synthetic oil instead of 5W-20 for this.

Also, FYI, when oil is picked up from the pan, it passes through a screen that'll keep the boulders from getting into the oil pump and then it goes through the positive displacement oil pump directly do the oil filter, and then on to everything else. If you use a high quality filter, it should keep almost any contaminants from getting into the rest of the engine. One other thing, the valve train is the last thing in the oiling circuit to receive oil, specifically the valve lifters, that get their oil down from the rocker arms down through the tubular push rods.

If this doesn't work, then I think I'd entertain the idea of tearing into the engine to see exactly what is going on. Good luck and keep us posted on your findings.
 

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Discussion Starter · #6 ·
what diagnostic tool would i need to get inti the system and trouble shoot everything?i have looked online and seen some for around 200 and up.but i dont know if any at 200 woild be enough or it would take something that cost thousands to do it.i dont mind spending a couple hundred on a tool knowing i can use it on other vehicles.

going to start digging into the info you have stated and see what i can find.it started oit eith p1417 then p1414 was coming up once the additive was added.i didnread elsewhere where jeep users had used it to fix mds issues.it took me a couple weeks to finally buy some.i placed it in at night when i only had p1417 and when i started to drive to work..it had issues,i drove home and checked.then both codes appeared...appologies if codes were confusing.i had to check photos for the codes.

before when i got p1417.i could shut the jeep off and restart it.that made the code and issue go away.that was 2 weeks after oil change and trip to LA.i forgot to that info earlier.




This is interesting! The MDS cylinders are 1, 4, 6, and 7, so it would appear that it does have something to do with the MDS or its components. I think, for starters, you'll need to have someone check the engine management system with an advanced computerized diagnostic scanner that can read all modules. Your P1414 DTC definitely indicates a problem with the No. 4 cylinder MDS deactivation. This could, at least in part, have been caused by the wrong oil being put in the engine. I am guessing you didn't have this problem before the wrong oil was put into it??? Anyway, below are some of the possible causes for this code and you'll notice that it does include the lifters and restricted oil passages. Could your engine restore stuff cause carbon or sludge to come loose, I don't know? Only an engine tear down will tell you for sure it this has happened. When you replaced the MDS Solenoids, did you use Mopar ones or aftermarket? I've heard there have been problems with some of the aftermarket ones.

P1414 Possible Causes

(K452) MDS SOLENOID NO.4 CONTROL SHORT TO VOLTAGE
OIL PASSAGES RESTRICTED
LIFTER
MDS SOLENOID NO.4
PCM

I've found it hard to find what I consider "good" information on the P1714 DTC. Below are some of the symptoms and your description of the problem definitely fits what you're experiencing. Below you'll see some of the info. I found describing the types of cylinder deactivation systems used today. So far, I haven't really found a "for sure" solution to what is going on. Also, see the "Possible Solutions" I found on one website.

P1714 Symptoms
  1. Check engine light comes on
  2. Engine stalling or misfiring
  3. Engine performance issues
  4. Car not starting
There are currently two main types of cylinder deactivation used today, depending on the type of engine. P1714 Chrysler Dodge code for the pushrod design which uses solenoids to alter the oil pressure delivered to the lifters. In their collapsed state, the lifters are unable to elevate their companion pushrods under the valve rocker arms, resulting in valves that cannot be actuated and remain closed.

P1714 Possible Solutions

The crankshaft sensor signals the fuel injection computer or the ignition control when the cylinders are firing. This causes the ignition coil to provide a spark and the injector to inject fuel into each cylinder at the right time.If either sensor isn't working correctly, the car will run rough and the engine will be less efficient. In later car models, the car's computer can usually keep the vehicle running, but the engine warning light on the dashboard goes on to warn the driver.

The cam and crank sensor inputs (they must be synchronized with each other using a high end scanner) to the PCM are the two main signals that it uses to determine fuel injector pulse widths and timing. The fuel injected and MDS lifters collapse MUST occur at exactly the same time. If the valve timing is off because of a valve train problem (such as bad a lifter), this would throw everything off and cause misfires, rough running and stalling. Faulty fuel injector(s) and/or PCM could also cause this. Also, since you are now getting valve lifter noise, that possibly indicates a stuck or failing valve lifter, bent push rod, flat cam or ?

What to do, that is the question???? I'd say it's totally your call but, if this did start after the wrong oil was put in it, I think I might try finding a very strong detergent oil that could disolve any contaminants that may be either plugging passages or causing the MDS lifter(s) to not freely move from the activated to deactivated position(s). Be aware that there is a moveable pin in the MDS lifters that activates/deactivates (collapse) the lifters. (I have heard of the pin failing, but very rarely.) Using any engine additives is something I would never normally do, because it could cause more harm than good. I think if you first pull the valve cover(s) (just one would be OK) and look to see if the rocker assembly area is all gunked up, If it is, I wouldn't do it. If it's quite clean as it should be (both of my 5.7's run synthetic oil and are totally and completely clean), then I'd go ahead and try it. You may have to change the oil/filter a couple more times to "flush" any.all of the stuff out. Use your judgement, depending if things improve or not. Be sure to follow the instructions on whatever product you choose to use. You may also want to try using lighter 0W-20 weight synthetic oil instead of 5W-20 for this.

Also, FYI, when oil is picked up from the pan, it passes through a screen that'll keep the boulders from getting into the oil pump and then it goes through the positive displacement oil pump directly do the oil filter, and then on to everything else. If you use a high quality filter, it should keep almost any contaminants from getting into the rest of the engine. One other thing, the valve train is the last thing in the oiling circuit to receive oil, specifically the valve lifters, that get their oil down from the rocker arms down through the tubular push rods.

If this doesn't work, then I think I'd entertain the idea of tearing into the engine to see exactly what is going on. Good luck and keep us posted on your findings.
 

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OK, the other code is P1417. That makes more sense. Again, what brand MDS Solenoids did you use when you replaced them? If they're aftermarket, there have been brand new ones that didn't work, or didn't work correctly right out of the box.....I am sure made in China.
 
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