Lifter tick/throttle issues/fuel issues

[Bobby Rae Allen]

All,
Below is my current engine troubleshoot situation in the most detail I can provide. Thank you for taking the time to read.

2012 Ram 2500 HD Hemi with 96k on it, purchased at 91k
-drive it 2-4 days a week, usually just short errands during the week and highway on the weekends
-infrequent towing
-6 speed auto shifts beautifully, truck has a ton of power and is up to date on maintenance

-Lifter tick started becoming audible around 94k (confirmed by mechanic)
-at 95,500 +/-, I noticed that the truck was bogging down while accelerating at all speeds
-by this, i mean when i attempt to increase the throttle, the truck struggles to get above 2000 rpms as if something is holding it back, then as i increase pressure on the pedal, something finally kicks it up to 3000+ rpm and it launches as if i was trying to do that, which i am not
-this bogging down is slightly intermittent at cruising speeds, and usually occurs in the 1600-2000 rpm range
-It is MOST noticeable and predictable when the truck is "under load" (entering a highway, going up a steep hill, or just getting on it to pass someone)
-truck idles beautifully, and once it is past the bogging range, and does kick up to that high rpm, it has nothing holding it back and feels just like it did before these issues (no i don't drive like a maniac, but yes i do know what the top end feels like when I goose it)

*note: since this issue started, my mileage around town and highway has decreased 30%, probably due to having to basically floor it to get it going past that bogging down range

-I had it in to our mechanics for diagnostics of this issue...
(Disclaimer: extremely reliable for 12+ years and 10+ of our vehicles. Very good relationship, I truly believe they did not try and screw me on this. So don't start with all the talk about "oh they tried to screw you..." etc. They are fully refunding the work before we proceed with anything else.)

-They took a sample of the fuel and found there to be metal particles in my gas (a result of bad gas or nasty additives eating away at inner lining of gas tank) I saw it myself, looked like macroscopic aluminum shavings floating around in there. Not good.
-They proceeded to replace the gas tank, fuel pump, flush the lines, fuel rail (bad anyways), and injectors with all Mopar parts. 3700 big ones. Ouch.
-Drove it off their lot only to have the issue immediately persist. No better, no worse.
-Although the fuel issues/bad gas may not have been the cause of whats going on, I'm glad we caught it and now I have a brand new gas tank and injectors. Hooray.

Once the refund is processed, it is back to square one. So here is what we think may be going on:

-Lifter tick is loud enough (under load) that it is tripping the knock sensors and reducing timing, perhaps imitating a fuel or air issue, but in fact is just the engine trying to save itself.
-This could be why it idles fine, and runs great when above a certain rpm range (This gets my vote personally, but I'm a novice)

If anybody has any input, similar experiences, or advice on where to go from here, I really appreciate it.

 

[Gmjrpayne]

This sounds so familiar had the same issues .......I hate to say it but it most likely is a lifter failure ( taken mine apart as we speak ) which means replacing the cam .. Have you gotten any misfire codes ? The easiest way to tell is to remove the valve cover ,take out the fuse to the fuel pump and turn the engine over and watch the rocker arms move up and down ( several videos posted )..look for the rocker arm not moving or moving very little ...

 

[huntergreen]

Do a search on lifter cam failure and see if the symptoms match what you have.

 

[Burla]

You are a mis-fire code away from replacing the cam/lifters. You might opt for 5w30 redline oil and a RP filter, but you might be past the point where that can help. Sad to say for a large number of these engines, 75-125k miles seams to need lifter/cams. You bought at 91k, you bought someone's problem, I hope you got a good price. There is no way that problem didn't exist at 91k, I bet they dumped something in that quieted for a while. Did the tick show up after an oil change?

 

[Fitz-0518]

In addition to reading the post on this subject, as suggested. Did your guy run a full scan. A good tech like you have, typically have a professional tool that can look at run specs compared to factory specs. Maybe hoping that it is not a cam expense, but if it is, knowing that the diagnostic read confirms it, would make me comfortable with the expense decision. That said, the metal particles in the fuel system worry me. If they got thru the fuel system and into the valve train. NG

 

[Bobby Rae Allen]

Hey guys, thank you for the prompt response. I can’t say for sure if the tick started after an oil change. But that would make perfect sense. Good thing I did get a good price on it. I’m also about to sell my Tacoma project truck. Not a huge deal on cost I just want it fixed. If that means my hemi won’t sound like a sewing machine anymore too, I’m happy. I brought it in to the shop so tomorrow they are going to call me and we will troubleshoot some of the things discussed on here.

 

[Bobby Rae Allen]

Update: My mechanic does have a live diagnostics tool to grab the specs from the engine. He is going to revisit it tomorrow morning when the truck is cold. The lurching and bogging down is more pronounced when cold, or when under load he said. Those are the only two patterns we can find because otherwise it is intermittent. Just sold my project truck tonight so I have a little more comfort in the budget going forward, but just out of curiosity, how much would getting new lifters and cam cost me? (ballpark) Is that classified as an engine rebuild?
haha I've never had to mess with an engine to this degree before. I had a 5.2 318 in a grand cherokee that ran flawlessly (everything else on the truck broke, don't worry). and I had a 4.7 in a 1500 that ran flawlessly. I just had to go and buy a Hemi didn't I?

 

[huntergreen]

Not sure a cam lifter issue would be intermittent. If I am wrong, I have heard pricing from 3 to 6 grand. You might consider up grading the parts if you have to get into the engine.

 

[Bobby Rae Allen]

Is it possible that the cam/lifter issue could be mild enough to not throw a CEL for misfire, but loud enough to trip the knock sensor and cause bad timing?

btw I have started to think about whether I want to upgrade the cam, an I'm sure there are ample threads about that so I won't crowd this one with it.

 

[huntergreen]

Is it possible that the cam/lifter issue could be mild enough to not throw a CEL for misfire, but loud enough to trip the knock sensor and cause bad timing?

btw I have started to think about whether I want to upgrade the cam, an I'm sure there are ample threads about that so I won't crowd this one with it.

I am far from a mechanic, but imho, maybe? Could also be a cracked motor mount or a software issue.

 

[Bobby Rae Allen]

Update: I have never been so happy to see a CEL in my life...

Went and got the truck from my mechanics today. After 8 days of labor and them replacing the entire fuel system for 3700 dollars and having to refund it, I guess they finally decided to call it quits. I completely understand. They told me to take it to a dealer or another set of eyes and call them when I figure out whats wrong.

As I was driving it home, it was continuing to bog down like normal, and I was lets say... disheveled at this point. So I was rolling at about 15 mph and just matted it and held on. As soon as she peaked at 5500 rpm or so, CEL CAME ON! FINALLY! Drove that sucker straight to autozone and scanned it.

P0305 Cylinder 5 Misfire (Just like all the other cool kids)

So... now I'm back at square one. New fuel system, cleaned throttle body, some budget, and a little more info in the form of this code. Where do I go from here?

 

[Bobby Rae Allen]

Also... Just read in another thread about how the bad lifter/camshaft has the ability to effect the position of the intake valves and exhaust valves. So on top of making the other cylinders work harder, it is also messing with the intake and exhaust... which would get worse as the load increases and more air is getting told to come in/exhaust told to go out! I hope this makes some kind of sense, especially for my specific symptoms and situation. Thoughts?

 

[Fitz-0518]

This is not talk down. Realy want to see you get your truck back on line. We can all offer our thoughts. Share what experience we have had when we have had conditions and codes that are similar. You heve some of the best on the forum responding. But the real answer to what your truck is suffering from can be found through a live running scan. A tech who has that type of equipment and has the patience and experience to dissect air, fuel, spark and factory specs versus what your truck is displaying is worth the time and money.

 

[huntergreen]

Sounds like your having a lifter failure possibly grinding down a cam lobe.

 

[Ramnewbie]

This is not talk down. Realy want to see you get your truck back on line. We can all offer our thoughts. Share what experience we have had when we have had conditions and codes that are similar. You heve some of the best on the forum responding. But the real answer to what your truck is suffering from can be found through a live running scan. A tech who has that type of equipment and has the patience and experience to dissect air, fuel, spark and factory specs versus what your truck is displaying is worth the time and money.

This live running scan you speak of, is this something special or is this what it is when they hook it up to the big computer? If it's the big computer I've only ever seen that used once to diagnose a car that I had and it still took a tech that had alot if patience to figure out what the problem was. Turned out to be a bad ground and took all of 2 seconds to fix.

Sent from my XT1650 using Tapatalk

 

[Bobby Rae Allen]

This is not talk down. Realy want to see you get your truck back on line. We can all offer our thoughts. Share what experience we have had when we have had conditions and codes that are similar. You heve some of the best on the forum responding. But the real answer to what your truck is suffering from can be found through a live running scan. A tech who has that type of equipment and has the patience and experience to dissect air, fuel, spark and factory specs versus what your truck is displaying is worth the time and money.

Is this the sort of thing that would (dare I say) justify me taking it to a dealer? or should I do some searching for a shop that is capable and willing to do that level of diagnostics?

 

[Fitz-0518]

Is this the sort of thing that would (dare I say) justify me taking it to a dealer? or should I do some searching for a shop that is capable and willing to do that level of diagnostics?

Bobby, tough question. If I knew that the dealer was competent, then yes. My experience has been, a local shop that has a competent reputation that others tell me, "this guy got to the bottom of the problem and fixed it" is my preference. I am "very" fortunate to have a tech that grew up in the Dodge-Ram truck world. Has the right scan tools and he is a bull dog with a peace of meat. If you could find that type of shop, that would be "my" first choice.

 

[Fitz-0518]

This live running scan you speak of, is this something special or is this what it is when they hook it up to the big computer? If it's the big computer I've only ever seen that used once to diagnose a car that I had and it still took a tech that had alot if patience to figure out what the problem was. Turned out to be a bad ground and took all of 2 seconds to fix.

Sent from my XT1650 using Tapatalk

I don't want to get over my pay grade, but this is what I understand. My tech has a cabinet of scan tools. I have seen him connect two when diagnosing my 5.7. What he has explained to me, one tool is looking at intermittent codes retained. The other is looking at what the ECM is saying/doing while running. He can compare actual operating data to factory specs. What I have come to understand. Just because a check engine light sets a TB code, that does not mean you need to replace the TB. It may mean that something that is connected to the TB is causing the TB code. One of these tools is connected when he drives the truck. He can look at air, fuel and spark. My last check engine light, lightening bolt, limp mode was two bad grounds. One under the fuse box and one to the engine body. In that case I saw the scan tool in what ever mode allowed him to see electric readings compared to factory specs.

 

[huntergreen]

Is this the sort of thing that would (dare I say) justify me taking it to a dealer? or should I do some searching for a shop that is capable and willing to do that level of diagnostics?

Depends on the dealer. My first thought since you are out of warranty, is a shop the specialized in engine rebuilding. At the very least, get some quotes.

 

[RysRam]

I don't want to get over my pay grade, but this is what I understand. My tech has a cabinet of scan tools. I have seen him connect two when diagnosing my 5.7. What he has explained to me, one tool is looking at intermittent codes retained. The other is looking at what the ECM is saying/doing while running. He can compare actual operating data to factory specs. What I have come to understand. Just because a check engine light sets a TB code, that does not mean you need to replace the TB. It may mean that something that is connected to the TB is causing the TB code. One of these tools is connected when he drives the truck. He can look at air, fuel and spark. My last check engine light, lightening bolt, limp mode was two bad grounds. One under the fuse box and one to the engine body. In that case I saw the scan tool in what ever mode allowed him to see electric readings compared to factory specs.

Amen, some of the best info can be found in the drive cycle checks, live sensor data and sensor self check tests. As you mentioned, these all exist along side of the CEL codes that get stored.

FWIW, you can access all this stuff using a $12 OBD2 Bluetooth module and $5 android/iPhone app. It won't have the same data update rate as a professional scan tool but it's still pretty handy.