I am new to the diesel truck world. I just purchased a 2014 Laramie with the 6.7. Love it so far. I don't know what is normal and what is not with these trucks and engines so here are the questions. Truck has 36,000 miles
1. When the engine is in 6th gear and I'm traveling at a moderate speed(30-40 mph) and I give it enough gas to get it moving, but not enough to downshift, the engine makes a knocking sound like when you put crappy gas in a car. Is this a normal Diesel engine noise? It seems to lessen when it warms up but doesn't go away entirely.
2. If I accelerate moderately, the truck seems to run through the gears really quickly and get bogged down top gear. It can also feel a little like the tranny is slipping if I give a little extra gas.
3. The front end gives a little clunk when turning left or right at slow speeds. Not loud, but noticeable.
Taking it to the dealer this week to have it checked out. I just wanted some baseline knowledge before I get their response. It was a certified truck so I want to make sure everything works properly before the warranty is up.
A lot of these may be answered with more info. What Trans do you have? How many miles have you put on it? What gears are you running? etc.
1.) The knock is not normal.
2.) The newer trans do seem to move through the gears very fast. They tend to bog in high gear instead of downshifting. that's normal. With that said the trans will "learn" based on your driving habits.
3.) the clunk in the front is probably the suspension linkage, that seems to be normal, but it wouldn't hurt to have the dealer look if its going to be there anyway.
Engine rattle at low boost is normal. Try running around the city with the tow/haul
mode active. It will hold the gears back a little more and reduce the rattling.
I have the 68RFE trans. I have put about 400 highway miles on it. It has the 3.42 gears. Is some diesel fuel better than other? I got this tank at a truck stop.
The engine knock is most pronounced when I'm in 5th or 6th gear and the engine is bogged down a little. It is the loudest right before it downshifts. Once it's in a better gear, the knock seems to go away.
In my opinion the knock is trans re engaging from a coast when you hit the throttle. Mine did the same thing for a while. seemed "jumpy" until I settle into the truck and I got used to the vehicle, the so called "learn" will adjust and the shifts will be smoother after a while as well.
I have the same setup and it gradually went away.
I would give it around 1000 miles or so and see if it gets better.
As far a fuel goes you should be fine at any truck stop or station where the fuel is cycled frequently.
The knock sounds like injector rattle. Like the gear is too high and rpms aren't. It's not that anything is wrong with your truck, just wrong gear for the rpm. Run with 5/6 locked out around town
Has all the computer updates been done along with all recalls completed, being a 2014 model???
With 36k miles on it has all the 30k mile maintainence been completed including the tranny fluid change???
There has been computer updates for the tranny shift pattern also. Has the fuel filters been replaced, they should have been replaced twice by now with 36k miles on it.
Lock out 6th and even 5th if you need to while driving around town until all of the above mentioned item are completed. There is a long list of maintenance items that should have been done to it by now. Look thru your book to verify what's needed, there's more than an oil change needed. Ask selling dealer for any maintenance records.
Other than tire rotations, oil changes and fuel filter changes, there is no maintenance required by 30k for a non-aisin truck, assuming that's what the OP has.
I was or still am new to the diesel. If you hear a knocking in the laramie with the windows up, that does not sound normal.
I have gotten use to the engine bogging down because it quickly shift to such a high gear, but going down the rural road here it get 32 MPG at 35 MPH 100% flat road, I would much rather get less MPG going 50. A lot of people say drive around in tow haul mode or lock out the upper gears, to it seems to only make it get much worse MPG and override the RPM Ram and Cummins engineers decided what was best for those conditions. I think I am going to trust Ram and Cummins and just let it lug down the road, it seems happy cruising at 1k RPM, and it is not a gasser so it should not be turning the same RPM's as a gasser. I actually posted that same related question here a month ago. Now I do not even notice the lugging feeling, guess I am used to it.
Are you sure the clunk if the front end, letting off the gas in these can cause a clunk, does it clunk if you have cruise control on when going around the turn, you could be letting off the gas to quick causing it. Mine does not do it nearly as much anymore, I guess it learned my driving habits and I learned to let off the gas a little more gently, but I noticed it on straight roads also at first.
... A lot of people say drive around in tow haul mode or lock out the upper gears, to it seems to only make it get much worse MPG and override the RPM Ram and Cummins engineers decided what was best for those conditions. I think I am going to trust Ram and Cummins and just let it lug down the road, it seems happy cruising at 1k RPM, and it is not a gasser so it should not be turning the same RPM's as a gasser. I actually posted that same related question here a month ago. Now I do not even notice the lugging feeling, guess I am used to it.
I assume that since the truck was certified when I bought it that the recalls would have been completed and the computer updated. How would I know for sure that they were done?
Highly unlikely! Contact the dealer for more info.
Better yet, take it in and have them update the systems.
Dealers don't update PCM's without Recalls or related faults
with TSB's.
You would probably find a few updates available
as they come out all the time. Make them check it!
Also make them document the updates applied on your
copy of the RO.
Diesel engines.... Especially when fueled up a little in 5th or 6th will produce a sound very similar to a gas engines that is having pre ignition. A sharp pinging noise. My first diesel I had was a '99.... And man did it make some noises!!!! Especially when the hood was open at idle and you're lurking around... And if you went underneath the truck while running you would've thought there was definitely something wrong with the truck.... But she just kept going and going and making noise. To me.... These 6.7 engines are just fantastic when compared to any 5.9 when we are talking noise. The 6.7 has a sound all their own... In my opinion ...at times they don't even sound like Diesel engines... They're so quiet...but at the same time.. You can hear all the weird diesel noises too.. Like timing advance under fueling before boost is present. My advice is just to keep a open ear... If a sound is present, has always been present,and is not getting worse...then it's most likely normal.
Just picked up my 3500 two days ago so I probably still have a bag over my head when asking an "intelligent" question about the 6.7. So I'm not sure how to recognize lugging. Currently when it goes into 6th gear at about 55 mph and if I don't keep increasing speed it levels out just over 1000 rpm and I'm tempted to force it back into 5th gear. Of course I'm not towing and on level roads. 68RFE trans and about 200 miles on it.
Any concerns here? Not lugging?
Lugging is when you mash the throttle at low rpms and the rpms stay the same and the engine can not gain speed. It's about impossible to actually lug a Cummins with a automatic transmission because the transmission will downshift before lugging occurs. Lugging happens mostly in manual transmission truck...
Definitely a thumb activated shifter for those with a right thumb. Gear up, gear down, go where ya wanna go at the correct speed and RPM's for conditions.
If I push the up shift button, it will up shift whenever the trans decides to do it, not the moment I press it. If I'm in say 6th and decide I want 5th and press it down, it drops a gear immediately.
My wife's Durango has paddle shifters and if use them I can up shift immediately and even lug the engine like a manual. Our trucks do not work like that.
If I push the up shift button, it will up shift whenever the trans decides to do it, not the moment I press it. If I'm in say 6th and decide I want 5th and press it down, it drops a gear immediately.
Yep, with an automatic there is no way to up shift and force the RPM lower then what Ram and Cummins chose to program, all I can do is allow it to up shift when it thinks is appropriate or prevent it.
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