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jhedman2 08-14-2012 10:37 PM

Searching for 5.7l help. Yet another issue.
Hi All,

So let me start by saying I've read this post ( and this post ( and several others, but I've found very little help, so now i'm asking you...

So, first off, I have realistic expectations when it comes to Jeeps and performance. This is my 5 GC so I'm well aware how they run. I'm not comparing it to Range Rovers or anything else. I'm comparing it to itself.

Last week, 2011 Overland 5.7l experienced something wierd. I didn't think much of it but early in the afternoon after drive for a bit, I was coasting to a stop light when the dash dinged and the VIC said ACC(cruise) is disabled and FCW OFF. It lasted for about 15 seconds, then everything went away and acted normal.

However, since then, this thing has been very sluggish. I realize it's not a fast vehicle, but it's always been faster than this. I've got 16k on it, so I have a bit of experience with it. So, the sluggish response is only once the vehicle is at operating temp. Otherwise, it's fine.

Here's the description of the issue. When accelerating from a dead stop, full throttle, the RPM climbs very slow (or much slower than it used to). It actually feels very similar to when traction control kicks in while in slow mode when it retards torque to prevent traction loss. The same feeling happens for example when turning right with some speed. Meaning when I cost through a light while turning right, normally I could hit the acceleration and feel some torque in the gear I'm in. Now, it's extremely low power until I hit the gas hard enough to where it downshifts, possibly all the way to first. Never had to do this before. One more important detail, the torque is extremely low from idle to about 3k rpm, at which point the power starts to kick back in. Also, after testing it for about a half hour, replicating the behavior everytime, I noticed a strong fuel odor, much like it was running rich. The smell was under the vehicle near the exhaust.

The dealership has driven it twice now and is telling me without engine codes, there's nearly nothing they can do, they have no idea where to start. I'm very frustrated, I spent a lot on this vehicle and I'm starting to regret it. It took them 6 months to fix a sunroof problem. now what? Meanwhile, I'm getting poor (worse than usual) gas mileage and poor performance. It's actually dangerous, you get used to your vehicles capabilities and now I find myself pulling out into traffic when I shouldn't.

In an effort to help speed up troubleshooting, has anyone experience the same issues and what would a dealership have done to fix it? Mine has already tried to pull codes twice and flashed the PCM, nothing.

Please help, I'm really getting frustrated. I've never had so many problems with a vehicle (that I didn't cause anyway)...

Xjrguy 08-15-2012 02:26 PM

Re: Searching for 5.7l help. Yet another issue.
Here are my suggestions.

Could it be a bad tank of gas?

Has anyone checked the battery condition? A borderline battery can cause very weird issues with these computer modules and engine controls.

Is the air filter dirty?

The dealer just wants codes because they don't want to diagnose the problem using common sense methods.

jhedman2 08-15-2012 11:23 PM

Re: Searching for 5.7l help. Yet another issue.
Thanks for the first reply.

Yup, run more than one full tank through it including some nice Lucas treatment. Air filter is completely clean... However, no I have not checked the battery, the incrediby good placement under the passenger seat makes it super convienent to work on :)

So in preparation, I've opened a case with Chrysler. Since they still don't do loaners, and my career relies on reliable transportation, I've told them this won't go the same as my sunroof where it took nearly a dozen trips to the dealership. I'm paid hourly in a way, so everytime I spend 1-2 hours in the dealersip, I'm losing money. We'll see what Jeep says. I'm losing confidence incredibly fast.

ekaz 08-16-2012 09:02 AM

Re: Searching for 5.7l help. Yet another issue.
Disable the ACC either in EVIC or by pulling the fuse. I'm wondering if it's in some type of fail-safe mode since that error popped up.

jhedman2 08-16-2012 10:08 PM

Re: Searching for 5.7l help. Yet another issue.
Good idea, I'll try that. I mean it's so strange that it really only crops up once the vehicle is at operating temperature. Cold start it feels perfectly normal.

Just so frustrated, one thing after another. Now my tailgate has a knocking noise that happens with bumps or anytime the vehicle flexes.

jhedman2 08-20-2012 11:54 PM

Re: Searching for 5.7l help. Yet another issue.
So I haven't had to disable the ACC etc, for some reason, it's amazingly gone... Lasted for about 1.5 weeks, about 3 tanks of gas, and lots of weird power issues (not electrical, power as in torque) but it's apparently cleaned itself up. Not making me feel good about things...

At this point, I actually wish it would happen again and pull some codes, so I could get the issue resolved before it creeps up again in 12 months and I have to deal with it again.

Does anyone else feel this weird sensation though? So while driving down the highway, say around 55-65 (even happens at slower speeds like 40mph), take the foot off the gas, you feel like the truck is heavily restricted by the tranny? i.e. you can see/feel the deceleration? Just seems weird and quite like a bit of waste of gas. My WK didn't have this sensation, or at least not as bad.

ColdCase 08-21-2012 08:51 AM

Re: Searching for 5.7l help. Yet another issue.
I feel the compression braking more in sport and tow/haul modes. The TC in these seem to allow more compression braking than previous models, perhaps the TC remains locked up on coasting. I've read a few posts here commenting on what seems to be more compression braking. I do feel some variations when cold, which many here refer to as shudder.

Your performance problem sounds like what I think you would see with a leaky injector, perhaps a bit of dirt got in there that eventually cleaned itself out. If thats the case, you will unlikely see that again. Not sure on these V8s, but on other models the shop could do a leak down test to check for a leaky injector. Not going to help you now, however. Someone real smart looking at the ECU data and comparing it to others may be able to figure that out, but it will need to be bad enough that the ECU is out of adjustment range for it to throw a code.

Perhaps there is a bad/intermittent/loose ground somewhere which can cause several electrical type issues and bad sensor readings. And there are a number of sensors that could be marginally bad.

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