oil consumption

I've used two gallons to an oil change with great success... You can actually run it 100%.

 

You might want to take a sec and pull the discharge line off your compressor and see if your passing oil there.

 

You will get better fuel mileage with less that the recommended amount. I found this out on my own trucks. I started using half a bottle, then the other half when I needed to put oil in.

I also made the mistake of changing axle and transmission fluids, and adding the recommended amount of Lucas there. My truck went from one that would coast on level ground like I had a 50MPH tail wind to one that felt like it was running in sand. My mileage droped almost 1MPG. After one trip to Ca and back, never getting over 5.8 on a truck that always got right at 7, I changed out the fluids again, with a very, very small amount of Lucas, which brought my mileage back.

Don't get me wrong, I like Lucas. I use it in my cars and anything else. But I only use less that half the recommended amount, more like 1/4th in auto engines. You can still feel it on the dipstick, makes the engine quieter, and does not hurt mileage at this amount. The company just wants you to use more so you can buy more.

 

Try Delvac oil, or something else like Vavoline, which I really like. If you are going 5000 miles before using oil, that leads me to think the additives in the oil are breaking down around 5000 miles.

 

Yea I second that...try switching brands of oil for a while and see how it goes...?

 

No one has mentioned this, but take an oil sample and get it checked. It is amazing what you can find out, such as high copper will show an oil cooler going out as well as other things. If that engine is moving towards needing a rebuild, you will see it in the oil samples..... high iron, high lead, high tin, etc. Plus the blow by would be eating away at the additive package in the oil at a pretty high rate. You can get an oil sample done at one of the quick lube places on their machine, but I would take a sample and send it to a lab. The cost is relatively cheap for the information it provides. the lab tech will provide some information about the sample if things are out of whack. They will call you immediately if you have real big problems.

Just a thought.

 

Hi Cowpie1 (and everyone),
I just got an oil analysis back from CAT for a truck I am about to buy. All levels are normal except iron is high at 78 (normal is 37). I am wondering why the iron level seems high and if 78 is something to be concerned about. CAT recommended cutting the filters, checking for debris and changing the oil and monitoring it. Any advice woudld be appreciated.

 

You want to check the air intake, remove it from the turbo and with a wet white towel, wipe the inside. if there is dirt you need to find the leakage and fix it the air cleaner housings and all connections must be clean and tight, If you have air cleaners on the outside of the truck and the dirt goes to the inside then you want to take solvent and wet the connections see if they are leaking.
If the silica number is low then check the oil filters and the magnetic drain plug for abnormal amounts of metal, check the end play of the crank, You may need a bearing roll in, and loose the Lucas. If you are going to do an oil change add a gallon of ATF 50k before you drain it and you are good proof that the motor is made to run with oil nothing extra.

 

Hard to say about the iron without a pattern of oil samples to compare it from. How long ago had the oil been changed? Was the oil in the engine the same brand/type as was previously used? Normally, if only one wear metal is high, it is not a red flag issue. Combinations of wear metals starting to rise give a better picture. Even bearings will show high level combinations of lead, tin, chromium, etc if they are starting to fail. For instance, if lead was the only elevated level, I would suspect a fuel addtive first before suspecting bearings. If the oil was recently changed, and the previous owner was not meticulous about doing services in a timely manner, the new oil could, in fact, be cleaning up residue in engine. It is also not uncommon, if the brand of oil is changed, that there will be a spike in a wear metal or two because of the change and will settle down with subsequent changes. Iron level of 78 is not in critical territory by a long shot. It is elevated, but so many factors could have caused that. Ask questions about what I mentioned regarding the oil and see what you get for answers. Cutting the filter is not a bad idea, and something probably everyone should do from time to time just to see what is being caught by the filter.

Generally, without any more information, I would not lose sleep over the sample if all other numbers are in normal territory. When I purchased the tractor I have now, I had gotten elevated levels of iron and lead early on. Not sure what previous owner used, as they were a fleet, so probably some bulk standard 15w40. I started off using a synthetic blend, and got a lot of weird readings early in the game until the engine got cleaned out and settled down. Synthetics and blends will "scrub out" the junk built up in the engine. After the first few oil changes, I have gotten consistent wear numbers equivalent to engines with half the age of mine.