This thread is not in the wrong section I have both a 2nd gen and 4th gen ram. I have 2010 Ram crew sport package 4x4 7460 miles 87 octane regular oil changes. Everything was find until I hauled 2 loads roughly at 1700 lbs and 1200 lbs for a total of 24 miles at 7320 miles. Problem is that sometimes while driving it sounds like it struggling and not running on all cylinders, sounds like a ricer. At 30mph flat road keeping steady on the gas pedal I was at 3500 rpm. Pulled over popped the hood everything looked fine started up again and ran fine. Next day while driving it only seemed to be hesitating at low speeds. Also in the driveway the lights on my side view mirrors were lit up with everything closed and lights off. Think possibly the PCM is adjusting to the heavy loads. Any Thoughts?

 

You are hauling 1200 and 1700 lb. loads with an engine with a compression ratio of 10.5:1 on 87 octane gasoline?

Good luck with that...


and before you guys start quoting the manual that says "89 recommended but 87 ok", I don't care what the manual says. EVERY Hemi I've seen with a dropped cylinder(s) has been running 87 octane fuel on a regular basis, except a few '03s that suffered from weak springs.

The pre-09 Hemi's compression ratio is 9.7:1 and I still wouldn't put the first drop of 87 octane in those, myself...

 

But I'm going to say it anyways. All I run is 87 octane - 47K miles and about half of it towing 4-5,000 lbs. Truck likes it just fine and the milage does not change at all if you bump up to 89 octane.

In any event, the truck should be under warranty, so take it in and let the dealer figure it out.

 

And you can say this because you've visually inspected the bearings, piston rings and lands??? If not, how can you truthfully make that statement?

And you believe that the 89 octane fuel recommendation has ANYTHING to do with fuel economy?

C'mon oldjeep, I know you're smarter than that!

Run what you want, it's your truck and your money.

But, I'm gonna throw this tidbit out there and y'all can decide what to run:

If your truck was built after 10/3/08 OR if built before that date and you have had the PCM flashed with an update dated after 12/16/08 then your PCM is recording pre-detonation occurrences.

You think they are recording this just for survey purposes? If you just know in your heart that 87 octane fuel is perfectly fine for an engine with a compression ratio of over 10:1 AND If you personally feel confident that your dealer and Dodge will repair your engine under your "Limited Lifetime Powertrain Warranty" should it have a major issue despite what the PCM has recorded then go ahead and buy 87 octane gas with confidence.

and that's enough of that, back to the OPs issue:

You don't often hear pre-detonation occurring, especially in modern engines and often it's felt by a sluggish acceleration and a poorer throttle response, which is why I suggested to the OP that his chosen octane of fuel, especially when hauling that kind of weight may very well be his issue...

 

Sounds like truck is just going into this crap MDS mode. Put it in tow/haul mode or knock shifter over to put in 5th so MDS does not kick in. Then get a tuner and shut it off completely !

 

Manual says it is fine, my experience says it runs fine using it. Given that the manual states it is ok to run 87 octane I'm not worried about my warranty.

In any event, the piddly little load he was hauling for 24 miles is not likely to be a factor in whatever his problems are.

And as for the compression = octane requirements, that may be true of old fashioned engines, but not modern engines. AT 10.5:1 the Ram has the lowest compression of any car I own. Little jap/korean motors are closer to 12:1 and are also rated to run on 87 octane. (example - our 2011 Kia Optima 11.3:1 compression - 87 octane is what they call for as well)

 

so, you think hauling 1700 lbs. in a vehicle that is rated for a MAXIMIM 1850 lb. payload capacity (including passengers and other cargo) is a "piddly little load".

C'mon man!!!

 

thats pretty much true the only real way to tell if pinging is causing damage is to look.

not exactly but close. all rams starting with the 1994 model will track pinging and store it. the 12/16/08 update has nothing to do with recording the knocks. it is TSB 18-040-08 which deals with predetonation which was happening constantly in the 2009 hemis between 1800-2400 rpm when mds kicks in when using 87 octane gas. originally we just told people to buy 89 octane but the pcm update detunes the engine so it doesnt ping under normal operation. the horsepower and compression is reduced slightly so 87 is ok unless you are pulling hills or towing or hauling. if you are hauling more than about 500 pounds in the bed id probably be running 89 same with towing much over 2500 pounds.

if the engine has the update you should have an authorized modification label that says part number 04275086AB stuck near the VECI label.

excessive pinging is looked at as abuse and the dealership where i worked has declined warranty compensation for engines that showed abuse. chrysler has sided with the dealership and the discretion of the service department manager each time.

 

AS far as the engine is concerned, there is no difference between having the 1700 in the bed or towing it.

 

I think its TSB 18-041-08. SO I have a question, if my truck does not have the symptoms described below, should I still ask for the reprogram?

TSB #18-041-08 Some customers may experience:
· NVH (noise, vibration and harshness) issues while the vehicle is operating in the MDS mode.
· Spark Knock between 1800 to 2500 RPM. This involves a PCM/TCM reprogram.