Owning A Diesel...educate Me?

jkski · April 1, 2008

It is looking more and more like the diesel will be my next truck, so I've got a couple of questions, having never owned one:

1) In the winter, do I have to keep it plugged in overnight, etc.? We do a good bit of snowmobiling in the UP where the truck will sit for 3 days while we ride.

2) How often do you change the oil? Avg. cost?

3) How often do you change the fuel filter? Avg. cost?

Any other routine maintenance items, feel free to let me know.

Thanks in advance.

cc1999 · April 1, 2008

Oil changes can be anywhere from 65-100 bucks.

We run our diesel trucks 8-10K between service

We change fuel filters every 16-20k

Fuel filter with service has been 120-150.00

I am in Kansas, it never gets cold enough here to need to plug in the late model Diesels.

RCH · April 1, 2008

It is looking more and more like the diesel will be my next truck, so I've got a couple of questions, having never owned one:
1) In the winter, do I have to keep it plugged in overnight, etc.? We do a good bit of snowmobiling in the UP where the truck will sit for 3 days while we ride.

2) How often do you change the oil? Avg. cost?

3) How often do you change the fuel filter? Avg. cost?

Any other routine maintenance items, feel free to let me know.

Thanks in advance.

1) I live in southern California so I don't know about that.

2) Every 10,000 miles with a good synthetic. I used Amsoil for my first change at 3,000. Just changed it again at 13,000 with Mobile 1 synthetic 5w- 40 made for turbo diesels.

3)Every 10,000 miles. The manual says it will go 15,000, but I cut the old one open and it looked pretty bad after 10,000 miles. I use shell with 10% biodiesel and 10 oz. of Power service from the gray bottle. If you live where it is cold you may want to use the white bottle as it has an anti-gelling ingredient.

You also want to change the external spin-on transmission filter every 10,000 miles. You can get them at any Allison dealer for about $10. If you get it from GM it will cost around $40 to $45. If you go to the Allison web site you can find a dealer near you. Dealer locator is in the upper right corner.

A lot of guys have been running 3qts. 0f 5w-30 synthetic motor oil in the transfer case, I switched as well and it runs much smoother. The oil has better lubricity than atf and a higher flash point so it will not vaporize and destroy your T/C because it was ran dry.

You might consider switching to transynd in your transmission if you live in a cold climate.

Check the gear oil levels in the front and rear differentials to be sure they are not low.

Have fun with your new truck, these trucks are awesome.

One last thing, these transfer cases have 1 flaw. There is a clip that holds the oil pump from rubbing against the case, sometimes these clips fall out of position. There is a fix for it and I posted the link so you can check it out. Or you can do a search for "Pump Rub" and find lots of information on it. I purchased the plate from the link, but have not installed it yet. Some have had the pump rub issue as early as 30,000-40,000 miles.

http://adaptacase.com/TC236CBRNY.html

Shaners · April 1, 2008

I drive my truck about 6K miles per year. So I only change the oil once a year and the fuel filter every other year.

An oil change, lube and state inspection just cost me $80 at my dealer...

BlackSilver · April 2, 2008

I've owned diesels for several years, using them for pulling a 14,000# GVWR 5th wheel RV.

I live in Minnesota, my truck sits outside (wifey's car owns the garage!) and have never plugged in --- never failed to start on the coldest mornings.

The Duramax holds 10 quarts of oil --- I use Rotella T (dinosaur) oil and best quality WIX filter I can find. Change it myself around 10,000 miles (or a little earlier if going on an RV trip). Cost around $45 depending on where I buy the oil. The "quick lube" guys will typically charge around $70.00.

Fuel filter every 15,000 miles. Cost of filter from GM Parts online about $35.00, more if you have it done at the dealer. Don't skimp and try to do this one "on the cheap" --- use only the GM oem filter.

Riverjet502 · April 2, 2008

I live in Iowa and have owned a Dodge Cummins for 16yrs. I use 15-40 Rotella Dino oil. I change my oil & filter myself for @ $30. I change oil at 2500-3000 miles. This was a lot of town driving and ideling. I ave 8500 miles a year. Diesel fuel is a dirty fuel. I change fuel & air filter once a year. 1st weekend in Oct. This way I head into winter with a clean fuel filter. During winter cold weather the fuel filter can plug due to the fuel waxing up or geling or just plain crappy fuel which makes it hard for the lift pump to pump the fuel through the filter. Cummins does put a heater prob in the base of the fuel filter to help prevent this. (Not sure if GM does this or not). As far as starting in cold weather never had a problem. (The starter on my 6.0L 3500 cranks longer) I would plugg it in when it got down to 30 or so just to have some warm air coming out of the defrost when it started. I do the same with the gas 3500. These diesels have big cooling systems and can take a while to warm up. They hold a lot of crank case oil too, so you want to let the engine run a bit to get things circulated before take off. If it was to drop below -15 degrees for a period of say a week, I would put 1/4 tank of No 1 fuel then fill the rest of the tank with No.2 just to help the fuel from geling. This will help lower the fuels pour point some. If you are looking to purchase a used diesel I would buy a 06 or early 07 that is pre blue tec. On Jan 1st 07 all new diesel engines have to burn Ultra Low Sulfer Diesel. Because of this all 3 manufactures are having troubles with the new emmisions crap that is installed on the new trucks, several people I have spoken with are cussing their new ride because of this issue. The emmisions requirements are mandated for 2010 and everyone is srambling to meet this requirement. They are not perfected in this dept yet.

chrisb1 · April 2, 2008

I have a 2008 GMC LMM Diesel. No emissions issues at all. When running the clean cycle, the mileage drops from 16MPG to 9MPG for only about 20 minutes of driving. Does not enter the

clean cycle very often. Normal mileage around town, country roads is 16MPG. On the highway at 60MPH, I get almost 20MPG and I have only owned the truck since 2/28/2008. In Oregon we never use a radiator cover. Never gets cold enough. We ofter run from high 20 degrees and up. Never an issue with the diesel at such temperatures.

Dealers here charge about $75 for a normal oil change. $70 more if the transmission filter is changed. Fuel filter replacement is about $73 installed.

gwrace · April 5, 2008

I have a 2008 GMC LMM Diesel. No emissions issues at all. When running the clean cycle, the mileage drops from 16MPG to 9MPG for only about 20 minutes of driving. Does not enter the
clean cycle very often. Normal mileage around town, country roads is 16MPG. On the highway at 60MPH, I get almost 20MPG and I have only owned the truck since 2/28/2008. In Oregon we never use a radiator cover. Never gets cold enough. We ofter run from high 20 degrees and up. Never an issue with the diesel at such temperatures.

Dealers here charge about $75 for a normal oil change. $70 more if the transmission filter is changed. Fuel filter replacement is about $73 installed.

I can't speak for a GM diesel but I have owned a 2004 Ford Excursion 4x4 PSD for the last 4.5 years. I only have about 25000 miles on the truck but so far reliability has been great. I bought enough bulk oil 4 years ago to cover the twice a year oil changes. I change the oil about every 5000 miles. I do run an after market intake, custom tune and 4 inch exhaust. Never had to change any fuel filters but it does take 15 quarts of oil and a $15 dollar filter with each change. I'm running about 425HP and 700lbs torque. I also have 285 size tires. Mileage in the city is 15-17 and about 20 fully loaded on the highway. Not bad for an 8000lb SUV/Truck. I pull a 10K travel trailer and average 12-14mpg

It's just to bad diesel fuel prices are so high. When I bought the truck diesel was 1.25 gallon and the sales incentives more than paid for the diesel upgrade and 5 speed transmission. With the new EPA regs enforced on the new diesel engines and fuel it's virtually impossible to justify the purchase of a diesel anymore. Check out the mileage of the new diesels compared with the older engines. Mileage has suffered as a result of the additional pollution controls.

Costs:

Engine-Allison 7-8K

Added cost of maint. oil, filters, upgrades

Diesel fuel almost $4 a gallon

Additional interest on a loan

Duramax mileage 15-17?

Gas 6.0L 12-14

Here in south Texas gas is about .50 cheaper per gallon than diesel.

We plan to buy a 2500hd this year but no matter which way I run the numbers I can no longer justify the purchase of the diesel.

BlackSilver · April 5, 2008

We plan to buy a 2500hd this year but no matter which way I run the numbers I can no longer justify the purchase of the diesel.

Then you've made the right decision. There are good reasons for buying diesel, but none of them are about running the numbers. Diesel ownership is more expensive than gas ownership, and you can only justify it if your truck works for a living pulling/hauling heavy stuff.