Hello all,
Let me preface the explanation of my issues with this - I am NOT a car guy, although I am not an absolute moron. So forgive me for my lack of knowledge of correct terminology, etc.

My 2008 Ram 1500 "Big Horn" 5.7L 4x2 has approx. 62k miles. I've owned the truck for a little over 1 year, driven about 6k miles (to/from work). I've notcied these issues over the last 3 months.

I'm having issues with bucking during acceleration, more pronounced when traveling up an incline, but still present even when on level ground. Twice the check engine light has come on while having these issues, but has extinguished within a few minutes.
The catalytic converter smells, but I can't see how it could be clogged with only 62k miles on the vehicle.

I'm planning on changing the plugs and wires this weekend (will be using Champion Copper Plus as per recommendations seen here), in the hopes that new plugs will solve the issue - I have no idea if the plugs have been changed previously.

I've no error codes to provide - might rent a codescanner and check it out this weekend as well.

Does anyone have any other ideas as to what might be contributing to the problem?

Appreciate any input.

 

Do the Key Trick( Turn the key to the run position back to off back to run back to off back to run back to off, 3 times total) it may give you a code that isnt turning on your check engine light on, if so we will go from there but as for changing the plugs good luck(just did mine) also plan for atleast 3 hours and have a good set of tools. Once you have changed them let us know how she runs

 

No error codes displayed - simply lines (--------) and a few second pause, followed by DONE.
Thanks for the tip - I'd heard about Chrysler vehicles and this key trick, but had never tried it before.

Definitely not looking forward to the spark plug change - 16 plugs ffs! - but hoping it solves the issue.

 

Yeah its a nice trick also this isnt releviant but the C code trick(Push and hold the trip button then turn the key to run) for your future knowledge.
And yeah the lady at oreillys didnt belieive me about them having 16 plugs so i made her a bet if i could prove they did have 16 plugs my transaction would be free but before we agreed on the bet another worker came out and proved it to her.

 

The obvious is TUNE UP, as to when it was last done and to what extent.

Of key areas that would cause your problem besides basic tune up parts (plugs, filters, etc.) would be a clogged Throttle Body, poorly grounded Throttle Body, clogged EGR and PCV valves. Although with any good tune-up, cleaning/inspecting all three should be commonplace...

 

Frenetic,

There was also a flash for this condition involving the MDS that may help with your issue if the tune-up does not do the trick. I have posted the service bulletin regarding this issue below. There was also a couple of recalls that may apply to your vehicle. If you want to PM me the Vin I can check if you did have any recalls and if they have been completed.

NUMBER: 18-006-10 REV. C
GROUP: Vehicle Performance
DATE: October 08, 2010

SUBJECT:
Flash: MDS Driveability Improvements
OVERVIEW:
This bulletin involves selectively erasing and reprogramming the Powertrain Control
Module (PCM) with new software.
MODELS:
2007 - 2008 (DR) Ram Truck
2007 - 2008 (HB) Durango
2007 - 2008 (HG) Aspen
**2008 (LX) 300 / Magnum / Charger**
**2008 (LE) 300C/300 Touring (International Markets)**
2007 -2008 (WH) Grand Cherokee (International Markets)
2007 - 2008 (WK) Grand Cherokee
2007 - 2008 (XH) Commander (International Markets)
2007 - 2008 (XK) Commander
NOTE: This bulletin applies to models equipped with a 5.7L engine (Sales code
EZB).

SYMPTOM/CONDITION:
The customers may experience that the vehicle has a harsh engagement or has a
buck/jerking feeling at low speeds of around 12 mph (19 kmh) to 15 mph (24 kmh). The
customer may also experience a harsh engagement or buck/jerking feeling during highway
cruise control operation from 65 mph (105 kmh) to 75 mph (121 kmh). These conditions
are caused by excessive MDS transitions.
The MDS low speed engagement point has been changed to 21 mph (34 kmh). In addition
to the MDS low speed engagement change, enhancements from V8 to V4 and V4 to V8 in
all ambient temperatures and operating ranges have been made to make all the transition
less noticeable to the customer.

 

I certainly hope the used car dealer I purchased the truck from was aware of, and followed through with any recall notices.
This particular dealer touts a "Quality Inspection" on all their vehicles.. however I think everyone is aware of used car dealers and their less-than up-front repairs.
I'll have to contact them to find out when the last tune-up was completed, and if the recall notices were addressed.

I don't notice any jerking or bucking at 12-15mph, or 65-75mph - I do notice some issue at around 45mph, however.

I've got the plugs and wires, and will be installing them this weekend. I'll get back to you folks as to whether or not the issue was resolved, or even affected by the new plugs. Hoping for a little mpg increase - 10.4mpg isn't terrible for this truck, but I could hope for a little more (1+mpg increase would make me ecstatic, honestly).

Thanks again for all the assistance and suggestions - while I'm not necessarily mechanically inclined, I am a computer buff. The computer hardware community is nowhere near as welcoming and helpful as I've found this forum to be - again, much appreciated.

Regards,
Frenetic

 

Hello folks, little update here.

I was able to replace 12 of the 16 plugs. The last 2 coil packs on the driver's side at the rear of the engine (facing the hood) seem to be impossible to access..
I'm sure most of you know what I'm talking about - I'll check in with some photos to illustrate my issue later this week.

The issue is a large round drum-shaped object (has brake fluid reservoir attached, so something to do with brakes?) that is within 1 inch of the last 2 coil packs.
Can I remove this object without creating further issues?

The old plugs were in terrible shape - the terminal (if that's what it's called, below the electrode) was about the size of a pin head, while the new plugs had a full 1-1.5mm in diameter. Way to go, used dealer, with your full inspection and tune up before sale!

In any case, even with the last 4 old plugs still in I'm noticing some improvement. I haven't attempted to replicate the bucking issue as of yet, as I'm waiting until I get the last 4 plugs changed out.

I'll browse around for an answer later on tonight, but if anyone has any insight I'd be extremely grateful!

Regards,
Frenetic

 

The round thing is your brake booster. I had the same problem still havent changed the last four plugs lol

 

Oh come on, if you're gonna change them get them all! You need a universal joint and extension set for your socket wrench, they are a pita, but not impossible.