Cat 3126 Oil Capacity, Type, and Change Interval (Guide)
The problem is the blow by. This is the term used when you over-fill your oil tank. The excess oil is expelled by the engine and it is called blow by. This expelling does cause a mess which is why many service departments do not fill the 3126 to capacity when the oil is changed.
If your oil change mechanic only fills your oil tank to 19 quarts, then you are running 3 quarts low. The 19-quart level is for the newer C7 motors and not for the 3126. The original 3126 had a 19-quart capacity but was increased to 22 to facilitate longer intervals between oil changes.
To learn more about this topic just continue to read our article. It has the information you want to know about so you can fill your 3126’s oil tank with the right amount of oil. The key is not to overfill it so you do not get the blow by messes.
How Much Oil Does a Cat 3126 Hold?
According to our research, the newer 3126 motors take 22 quarts of oil including the amount in the oil filter. If you have an older 3126 with a shallow oil pan, then you may only need to buy 19 quarts.
If you are not sure about the size of your oil pan, then check your owner’s manual to make sure. That will give you the exact amount you need for the model year of your 3126.
Always double-check when someone gives you a different figure. They may not have the same engine or model year as your motor.
Caterpillar 3126 Engine Oil Capacity
This motor was first introduced n 1997 and these models as well as a few succeeding ones will be considered the older 3126 engine. When you have this motor under your RV’s hood, then you are looking at filling it with only 19 quarts of oil.
The newer models were redesigned and Caterpillar did not want its customers doing frequent oil changes. The cost of that task can turn many customers off and send them to Caterpillar’s competition.
The redesign added 3 quarts to the oil capacity and you will need 22 quarts. However, it has been said that you won’t hurt anything if you only put in 19 quarts in these newer engines.
Cat 3126 Oil Change Interval
The oil change frequency will be determined by the oil pan size. The manual may state that you are to change the oil every 10,000 miles or 250 operating hours when the 3126 has a shallow pan.
If your engine has a deep oil pan, then you can change it every 15,000 miles or 400 operating hours. We recommend that you check your owner’s manual to make sure you get the right interval.
If you run old oil through the engine, you can run into some problems down the road. Make sure to keep a schedule so you know when it is time to change the oil.
What Kind Of Oil Does a Cat 3126 Take?
The most recommended oil we saw at one RV discussion forum was Shell’s Rotella 15W 40 oil. Almost 100% of the owners of the 3126 on that forum use this oil and they all report the same results-- not a lot of problems.
However, one owner ran into problems using this viscosity and had injector troubles that would run about $1600 to fix. If you have a 3126 with an oil rail injector system, you need to run 10W 30 oil instead.
This change did the trick for that owner. While the majority of 3126 owners may say one thing, they may not have the same engine or oil system as you do, and double-check first before buying any oil.
Cat 3126 Oil Fill Location
The general location will be at the top front of your engine. It needs to have easy access to make pouring the oil inside easier and keeps the mess to a minimum.
The specific locations may not be the same on all 3126 engines as one specific location was on the valve cover. Another location may be on the tube at the front and in the middle of the engine
You can’t miss it as it is a 2.5-inch cap and it may lead to the power steering pump. If you can’t find it, ask a mechanic that works on these motors. They should know.
Cat 3126 Oil Filter Number
There are 2 oil filter numbers. Most RVs with this engine will come with the Caterpillar 1R0739 oil filter and that is the regular spin-on filter everyone seems to get.
The second number is Caterpillar 1R1807 and it is the high-efficiency spin-on filter. It seems to fit perfectly but it may be a bit larger than the regular one. You may find that the parts application guide will call for the latter oil filter number which may add to some owner’s confusion.
Cat 3126 Oil Filter Location
The oil filter looks to be on the left side of the motor as you are facing it. It is in a well-exposed area that makes reaching it very simple. If it is not there, just crawl under your engine and look up. You should see it fairly easily.
The key to doing an oil change with this motor is NOT to fill the oil filter with oil before you put the new one on. There are engine models that need to have this done but not the Cat 3126.
Some final words
It is important that you fill your oil tank with the right amount of oil. You do not want to go above capacity as that will cause your engine to expel the lubricant and make a mess of the engine compartment.
It is okay to go 1 to 3 quarts less on the 3126 as that will minimize blow by and it won’t hurt the engine if you do this occasionally. The keyword is occasionally.
