gm 8.1 engine

Some of you are truly amazing. You can diagnose long distance, not even knowing if there is a problem.
The 8.1 using as much as a quart in 1000 miles is not all that unusual, qspecially if it only has 6000 miles total.
He did not state how much is being added, nor at what interval. He also has not stated what lubricant is being used, nor how hard the engine is being worked.
Either some have ESP or must be using PRECISSION GUESSWORK.
Throwing out possible scenarios only serves to confuse the issue without any fedback from the OP.

It would be good to hear back from the OP. Rgatijnet is correct-----an engine whose crankcase is overfull will use oil. The OP needs to do an oil change (with the correct size oil filter being changed) and be very careful of how much oil is used to refill and then check his dipstick. He can also try running a few hundred miles with the oil level at the low mark on the dipstick and see if it continues to go down.

He (and others) can also switch to a 5w-40, a 10w-40, or a 15w-50 oil which will slow oil consumption.

Conventional multi-vis dino oils will also shear down and become lighter oils with use-----especially under heavy engine loads like in a MH. This will increase oil consumption. Synthetic oils will remain much closer to their "higher" number under heavy use.

harold1946 wrote:

I should add that when I fill my crankcase, per the manufacturer's specs, it comes to just slightly(1/8") above the "add oil" mark on my dipstick. After 70,000+ miles on my engine, I usually go 5-6000 miles before I need to add a quart of oil. If I added oil up to the "full" mark on my dip stick, I would have overfilled the crankcase.

When was the last time you saw the dipstick of an 8.1 with the wrong markings? If the required 6.4 quarts are in, it is not over filled.
Sounds like your engine manufacturer has a problem with quality control.

I had noticed the dip stick was wrong when I did my first service on my 8.1L coach. There is no doubt that WH has a quality control problem on several things. That is why I have had three recalls on my coach. The facts are that IF I filled my 8.1L engine crankcase according to the "full" mark on the dip stick, I would be over filling it. Perhaps that is why several people, including the OP, are only getting 1000 miles before they add another quart. Since I do not use the dip stick as a guide as to when to add oil, perhaps this is why I can go 5-6000 miles before I have to add a quart to my engine. Since WH adds the dip stick when they build the chassis, I would say that the problem exists with them and not the GM engine. If you are happy with adding a quart of oil every 1000 miles, good for you. It seems that the OP is not, which is why he asked the question.

rgatijnet1 wrote:

harold1946 wrote:

rgatijnet1 wrote:

harold1946 wrote:

randallb wrote:
My guess is an over filled engine. The OP says he has to add oil every 900 miles but does not say how much. If it is between the marks it does not need oil!
Randy

My guess is you know nothing about the 8.1. :p
Tha actia instrument cluster will alert the operator whenever there is a low oil volum condition.

I guess I missed it where the OP said that his Actia dash was saying that he had low oil. IF the crankcase was overfilled, because of a dip stick error, and the excess oil was forced out, and the OP saw that the oil level was a quart low(by the dip stick) then the Actia dash would say NOTHING. The ACTIA dash will NOT alert the operator IF the system is filled to one quart or so OVER the required oil level.

The OP said neither. Simply stated he was adding oil every 900 miles, so he was getting that information from somewhere, its not important from where.
The fact is,it is not abnormal for the 8.1 to use up to a quart of oil every 1000 miles.

WRONG!!!!! It is very important where the OP is getting his information. If the OP is adding oil because of incorrect dip stick markings, which has happened before, than to continue to add oil over and above what is necessary can eventually cause a seal to fail, as well as plug fouling and other problems. There is a reason why the manufacturer specifies the exact maximum amount of oil to be used in an engine. Using too much, on a regular basis, will eventually cause problems, which is why I had earlier suggested that the OP fill the crankcase with the exact amount of oil needed, per his owner's manual, and see how THAT relates to his dip stick markings.

I should add that when I fill my crankcase, per the manufacturer's specs, it comes to just slightly(1/8") above the "add oil" mark on my dipstick. After 70,000+ miles on my engine, I usually go 5-6000 miles before I need to add a quart of oil. If I added oil up to the "full" mark on my dip stick, I would have overfilled the crankcase.

When was the last time you saw the dipstick of an 8.1 with the wrong markings? If the required 6.4 quarts are in, it is not over filled.
Sounds like your engine manufacturer has a problem with quality control.

I have an Itasca with the 8.1 Vortex, 47,000 miles. It uses about one quart of oil every 1,500 to 2,000 miles. Normal for this engine I believe.

I don't put a lot of miles on mine but change yearly. I use Mobil 1 5W30 and have never had to add oil in 39,000 miles. Yes, I do check it.

harold1946 wrote:

rgatijnet1 wrote:

harold1946 wrote:

randallb wrote:
My guess is an over filled engine. The OP says he has to add oil every 900 miles but does not say how much. If it is between the marks it does not need oil!
Randy

My guess is you know nothing about the 8.1. :p
Tha actia instrument cluster will alert the operator whenever there is a low oil volum condition.

I guess I missed it where the OP said that his Actia dash was saying that he had low oil. IF the crankcase was overfilled, because of a dip stick error, and the excess oil was forced out, and the OP saw that the oil level was a quart low(by the dip stick) then the Actia dash would say NOTHING. The ACTIA dash will NOT alert the operator IF the system is filled to one quart or so OVER the required oil level.

The OP said neither. Simply stated he was adding oil every 900 miles, so he was getting that information from somewhere, its not important from where.
The fact is,it is not abnormal for the 8.1 to use up to a quart of oil every 1000 miles.

WRONG!!!!! It is very important where the OP is getting his information. If the OP is adding oil because of incorrect dip stick markings, which has happened before, than to continue to add oil over and above what is necessary can eventually cause a seal to fail, as well as plug fouling and other problems. There is a reason why the manufacturer specifies the exact maximum amount of oil to be used in an engine. Using too much, on a regular basis, will eventually cause problems, which is why I had earlier suggested that the OP fill the crankcase with the exact amount of oil needed, per his owner's manual, and see how THAT relates to his dip stick markings.

I should add that when I fill my crankcase, per the manufacturer's specs, it comes to just slightly(1/8") above the "add oil" mark on my dipstick. After 70,000+ miles on my engine, I usually go 5-6000 miles before I need to add a quart of oil. If I added oil up to the "full" mark on my dip stick, I would have overfilled the crankcase.

rgatijnet1 wrote:

harold1946 wrote:

randallb wrote:
My guess is an over filled engine. The OP says he has to add oil every 900 miles but does not say how much. If it is between the marks it does not need oil!
Randy

My guess is you know nothing about the 8.1. :p
Tha actia instrument cluster will alert the operator whenever there is a low oil volum condition.

I guess I missed it where the OP said that his Actia dash was saying that he had low oil. IF the crankcase was overfilled, because of a dip stick error, and the excess oil was forced out, and the OP saw that the oil level was a quart low(by the dip stick) then the Actia dash would say NOTHING. The ACTIA dash will NOT alert the operator IF the system is filled to one quart or so OVER the required oil level.

The OP said neither. Simply stated he was adding oil every 900 miles, so he was getting that information from somewhere, its not important from where.
The fact is,it is not abnormal for the 8.1 to use up to a quart of oil every 1000 miles.

harold1946 wrote:

randallb wrote:
My guess is an over filled engine. The OP says he has to add oil every 900 miles but does not say how much. If it is between the marks it does not need oil!
Randy

My guess is you know nothing about the 8.1. :p
Tha actia instrument cluster will alert the operator whenever there is a low oil volum condition.

I guess I missed it where the OP said that his Actia dash was saying that he had low oil. IF the crankcase was overfilled, because of a dip stick error, and the excess oil was forced out, and the OP saw that the oil level was a quart low(by the dip stick) then the Actia dash would say NOTHING. The ACTIA dash will NOT alert the operator IF the system is filled to one quart or so OVER the required oil level.

randallb wrote:
My guess is an over filled engine. The OP says he has to add oil every 900 miles but does not say how much. If it is between the marks it does not need oil!
Randy

My guess is you know nothing about the 8.1. :p
Tha actia instrument cluster will alert the operator whenever there is a low oil volum condition.