Probably a question that's been answered before but here goes again:

Bought the truck in late June. In September, I changed the oil and filter(Valvoline Premium Blue+Fleetguard) at 2000 miles and then put 5500 miles on it in 2-3 weeks, towing a 6500 pound travel trailer all over the Western USA. Back home I changed the oil and filter again at 7500 miles in early October.

I've been using the truck for short trips around town about four days a week and not putting many miles on it otherwise. I've got a trip (less than 1000 miles roundtrip towing the trailer) coming up in mid-April. I was planning to change the oil before leaving but realized I only have 2500 miles on the oil after nearly 6 months. Seems like a waste to dump out 3 gallons of oil that has had so little use. Checking it, the level is fine. It's no blacker now than it was the day after I changed it in October.

With gas vehicles, I've always changed at 6 month intervals due to the low mileage. Does that hold true for diesels as well or is it reasonable to stick with the recommended 7500 mile changes?

 

I do a lot of short trips and no towing so far since I bought mine. My feeling is that the fuel can get contaminated with unburned fuel if it's started/stopped on short trips a lot so I change it at least once a year no matter what the mileage. You can't see the bad stuff that's in there and the soot doesn't really hurt that much. In fact if you don't see soot it's cause for worry.

I'd say your 6 month/7500 miles interval is about right. If you haven't been 6 months yet and are under 7500 miles then don't change it.

I've been told that since I'm using fully synthetic oil I should be able to go 10,000 miles without a problem but I'm sticking with the 1 year limit since I do a lot of short in-town driving.

Edwin

 

Yeah, I have the same issue. One month I put on 7500 miles, but there are other times when a year probably goes by to get that milage.

I noted that there is no time frame specified in the owners manual or the factory service manual, and I know blow by in diesels doesn't turn to hydrochloric (sp) acid like in a gas engine.

A guy at the dealership said they used to recommend 6 mo minimum for gen 1/2 but could probably go 1 year with common rail.

Personally, I don't go more than about 5 months, regardless of milage. Probably more often than I need, but better that than not often enough.

 

Have you low-milers concidered installing one of the bypass type filters that helps with the removal of the acid forming ingredients that are generated by your short trip/long time situation? I know there is one that uses heat, which makes sense to me, and the Frantz unit with the toilet paper which absorbs quite a bit of water.
Just a thought.

 

There used to be a centrifucal filter that ran off the fan belt. It cleaned the oil so well that it always looked new. Anybody use one of them? My honda SuperHawk had one built in that never got cleaned. I discovered it by accident when I had it apart once. It was buried in the crankcase and ran off a chain.

The one I saw which ran off the fan belt had to be taken off and disassembled to clean but it was good for 50,000 miles or so. I don't know how it did with acids and HC's or other stuff that wasn't a solid particle like metal or carbon.

Edwin

 

The centrifugal bypass filters I'm familiar with run off oil pressure.

 

I recommend that my clients change their oil every time they refuel!





But I have a quick lube business


LOL... I can't even get them to check it!

Oilguy

 

I once had a Fiat with a centrifugal oil filter in the crankshaft pulley. It worked really well with no used filter to dispose of.
- Chris

 

It might just be me, but here is how I have had the oil changes.
Long drives home to Houston TX. 7,500 miles. It was only about 6 weeks.
Now at home mostly short trips, less than 5 miles. 3,000 miles or 3 months.
Everyone has their own way of doing it.
When I had a propane powered van, ran synthetic 25,000 between changes.

Do what ever feels right for your truck and use.
Personaly I would change oil before the trip, then on the return.

 

Hello everyone.

Here is my 2 bits.

If you really want to know what your engine is doing, if your oil change intervals are correct, take an oil sample.

We had our own repair shop for 16 years and the very best place to have a proper oil sample was http://www.metrotechsystems.ca/

We tried Finning and a few other places that did Oil Analysis and MetroTech was the best.

Not sure what a sample costs these days, but it's well worth the cost,why?

Well for those that don't know, here is the skinny:

Many things break down the additive package that are put into oil by oil companies. Heat, friction etc. Probably the biggest worry in my mind anyway is acid. Oil has sulpher in it. There are additives to combat this, but over time they get used up. Everytime you run your engine and then shut it off for a period of time, say overnight, the moisture in the air condenses. This mixes with the sulpher in the oil and makes sulphuric acid. (yes you get some sulpher from fuel too) The additives fight this, but as the additives wear out, the acid starts to accumulate.

The only way to know the level of this acid buildup is Oil Analysis, (unless you really stretch your oil change intervals, at which time engine damage will tell you the acid was built up too much!!)

Anyway back to oil samples. If you get a sample bottle, send it to Metrotech, they will tell you if your oil was still good for continued use? If it was, you might want to stretch your time and or mileage out farther. If they tell you it was all used up, then you might want to shorten your oil change intervals?

When you get a proper oil sample done, you can also see what condition your engine is in? The sample will give you parts per million etc of all the different metals from your engine. It will also give you other things not from your engine. This will tell you if you need better air filtration etc.

Another thing is if you are interested in Off the shelf additives (snake oil )

We did a fair bit of research on teflon based crap and many other "new engine in a can" products. One that actually worked as it was intended was BG Products.

Nope they didn't use teflon of some other magic. They used the regular additives that the big oil companies used, just in a way that made the additive package last longer. So?? Well the base oil doesn't wear out. The additives that are put in it wear out and the base oil gets full of contaminents. What the BG Products did was extend the time before the additive package wore out. So you got less wear, less contamination and longer oil life. This extended oil change intervals, so it saved money.

In testing, combined with oil samples showing oil condition and wear particles in the oil, we found we could increase oil change intervals by 50% and still have a better oil sample result come back, compared to oil by itself. This was using BG Products "Diesel Oil Conditioner".

I don't know if BG still make this stuff, but it is something to check out along with oil samples??

I guess that's a little more than 2 bits eh??

Mike.

PS: anyone needing more info on oil samples etc. can e mail me....

 

I change my oil, oil filter, and fuel filter every 6000 miles regardless of how I drive it.

 

[QUOTE=ijeepbc]
Many things break down the additive package that are put into oil by oil companies. Heat, friction etc. Probably the biggest worry in my mind anyway is acid. Oil has sulpher in it. There are additives to combat this, but over time they get used up. Everytime you run your engine and then shut it off for a period of time, say overnight, the moisture in the air condenses. This mixes with the sulpher in the oil and makes sulphuric acid. (yes you get some sulpher from fuel too) The additives fight this, but as the additives wear out, the acid starts to accumulate. [QUOTE]

The water forming problem in the first place is due to the condensation of humidity in the air upon cooling and then reacting with sulfur compounds in fuel and oil that are present in the crankcase. Over time from numerous engine shut offs the accumulated condensed humidity forms a significant amount of water in the oil to react with significant amounts of sulfur to form strong engine part damaging acid.

A means of preventing water build up is to heat the engine up on each run enough to vaporize the water out of the oil. The long periods of heat is why crappy grey looking water ladden oil will become shinny and new looking after a long trip over a number of days involving extended hours of driving. I also always fuel up my truck after a days driving before I park the unit. On short trips I top up the fuel after the tank level is down a quarter tank. Keeping the top of the fuel tank full as possible minimizes the amount of himid air present in the tank to condense. To help my engine oil get rid of water, I plug my block heater in for about four hours before I use the truck even in the summer to make sure the engine comes up to operating temperature quickly and has the longest time at operating temperature to boil the water out. I use a winter front over the radiator in winter. My truck is a work truck and not a daily driver. I also have an engine coolant heater to heat the engine coolant when no plug-in is available. I am thinking of installing an engine oil heater to plug-in before starting the engine, but the majority of my trips are long so it may not be worth bothering with. A load for the engine to labor against for a long period of time is good for the oil from heat developed in the oil refining the oil somewhat. Mileage does not deteriorate oil, it is the contamination in the oil that will destroy the protective additives.

 

since you guys are talking about oil changes Ive got a question. I have 2 gal of delo 400 and several gal rotello would there be any prob mixing on a oil change or two,both are 15w40.