I am starting to feel like something may be going south on my truck, but I don't know if it is the engine or the tranny. This is my first diesel as well as my first auto tranny so I don't really know what I should be looking or listening for.

What has brought this on is what feels like a loss of power, and pathetic fuel mileage. The transmission has always felt like it has had a problem finding the right gear and shift points and the engine has always knocked. I have 5k miles now.
I have been driving a 35 mile stretch each way lately, mostly flat and speeds around 50 to 60 mph. Empty I am getting an average of about 12 mpg on this run ( 9.9 mpg empty in town), a far cry from others who claim 17 to 21 mpg running 70 mph. Lately, the truck is feeling sllllooowwww and having to drop a gear for some minor inclines. Off the line, I have to get it up around 2300 to 2500 RPMs just so I don't have someone run up my tailpipe when taking off from a stop light. The engine sounds like it is pulling a sled at a truck pull, but the trucks acceleration does not match the engine IMO. If I'm at a dead stop on a hill or boat ramp, I nearly have to redline the truck before it will slowly start to move. The tranny has felt like it has slipped on a couple of occasions under moderate to hard acceleration, but the knock makes me think it could be a leaky injector as well.
I know I complain a lot, but I just want to know what others here suggest before approaching the service writer. Many of you guys know these trucks better than the dealership. I've ask these questions before, but this time the truck is going to the dealer so I want to be prepared. I bought this truck to last me for years, but I feel at times that it is showing bad signs at 5k miles w/ no towing.

 

Wow!! Sounds like you've been thru the wringer.

Engine knock - make them test the injectors. It could explain the knock, poor performance and poor mileage.

2300-1500rpm to get off the line - make them test the torque converter and transmission. That beast should leap off the line (especially when empty). The slipping you describe and difficulty on the boat ramp sure sounds like a torque converter. There are some posts in here regarding torque converter stall speed. You might want to bone up on that before taking it in.

Good luck and let us know what happens.

Neil

 

How many miles and have you changed your fuel filter yet.
Did you check the tranny fluid level? Did you have the TSB for the tranny line done, the one that replaces the line due to a faulty connection to the cooler and MIGHT replace the cooler is it deemed bad?

 

I have a little over 5k miles. I did my first oil/ fuel filter change at 2700 miles. I cruise Dodge forums like a hungry shark, but I have never heard of a TSB on the 04.5 tranny. I have friends that work at the dealership, but they have not mentioned this. I will check first thing in the morning. Thanks for the info.

 

As you have a 04.5... I agree I don't think the tranny tsb applies, but check.

This is kind of off the wall, but did you have the computer recalibrated for those bigger wheels and tires? Might this throw off your shift points and maybe even effect fuel timing, etc.?

I can't see how this would effect your "off the line" performance, nor can I see how this would make your engine knock...(however bad injectors would, and coupled with an auto / 3.73's and oversize tires... could be the reason for your less than thrilling performance!!!)

Just a guess as I have no knowlege on this subject... but there are a whole lot of guys on this forum that do & I'm sure someone will give you the straight scoop, one way or the other!

Defdog2

 

Yep you really need to take it in. My tach has never even budged no matter what size of incline. I'm no expert either but I tend to agree with the torque converter.

 

If I am on a hill I have to goose mine pretty good to get them moving. I don't have the HO's but the TC must slip quite a bit on the SO California editions (235hp).

 

I firmly believe the mileage problems some are experiencing is caused by low fuel quality . I notice a BIG difference between stations in mileage and engine sound . When mileage was lousy truck was very noisy and sounded like detonation under acceleration . I drain my water seperator every few days and add Diesel Kleen (available at Wal Mart ) every fuel stop and what a difference !! Just changed oil at 2500 miles and did a 400 mile trip , running late for party was hammering her real hard 85-90 and averaged 14 mpg . Cummins runs these engines through 25 different tests before they are shipped ,and believe me they will not go out if they don't pass flawlessly !! Mileage woes I think are ..... 1) Poor fuel quality 2) DC install prob 3) Driving habits . I have done the air filter mod and intake baffles and silencer MIA and it has really improved . I also read Marco replaced the IAT sensor and it helped considerably . Just my 2 centavos .

 

Coolslice, take a look at the Transmission oil. If it ain't red looking it is Trany problems. If it looks kinda brown it is burn't. It will also smell funny. Sorry to hear about the problems with your ride. Keep us informed on what service center says.

Sittenbull