1030 ratings
Big Oil - Step by Step (noobfriendly)
By cpt.chaos
So, many people are trying to solve the Big Oil Heist, and failed to find the right Engine.
We want to help you out with a Step by Step Introduction.
This Introduction is based on the Overkill difficulty, so you may not consider all Points on lower Difficulty.

Step 1: Day 1
You have to go in silent or very fast, if you don't, they will burn the intel.
If you fail, and they do burn them, you can continue the heist, but it makes Day 2 harder to finish.
The most important target, the intel, is in a Titan safe.

Step 2: Day 2 - Find the server room
Okey, now we come to the difficult part, figuring out what the right engine is.
First of all you have to find the server room. There are three rooms where the servers can randomly spawn.
One of them is visible from the outside, if you have a good eye and a lucky spawn you can spot it. (picture below)
If it isn't the one visible from the outside, you know that there are two more possible rooms to drill into.
Find the server room, overrid the data and open the lab door.

I really recommend that you go silent, that way you have no cops to shoot you and you can be more focused on finding the right engine.

Step 3 : Solve the Puzzle and find the right Engine
You are so close to finishing now!
There's a whiteboard in the lab that shows you what color gascan each of the gasses will be.
You now have to search for two clipboards. (They spawn randomly, sometimes in the lab, sometimes you have to search about the house.)

One clipboard shows us what gascan we have to use, in our case, it is Helium.

Now we go back to the table and there we can read that Helium is a green can.
So our engine must have a green gascan.

The second clipboard shows us how many cables are going to the Hydrogen can.
The Hydrogen is ALWAYS the colour blue.
In our case the clipboard says 3x H. This means that we have to search for a Hydrogen can with three cables, the cables are random, so for instance, the clipboard could say 2x H, which would mean you would have to search for a Hydrogen can with two cables.

Okey, we already know that our engine must have a green gas can and a Hydrogen can with three cables. But we have to know what pressure our engine has.
You have to search for a computer in the lab, on it shows the pressure in psi (pounds/square inch).

In our case it says <5812 psi. You now have to convert the psi into Bar, because we can only see Bar on the engine.
If you don't know how to calculate psi into Bar, let Google do the work for you ;)
5812 psi is ~ 400 Bar. <5812 psi means lesser than 5812 psi, so smaller than 400 Bar.

Our Engine must have a pressure smaller than 400 bar!
(This picture does not fit with the screen on this heist, it's from another heist)

We found the right engine! We know the color of the gas can, how many cables lead from the Hydrogen can and how much bar it has. There is only one engine which meets all the requirements.
Now bag the engine and go to the Airfield.
Step 4: The Escape
This last part might be the hardest yet.
After throwing the bag into the chopper, the police are on their way. You can't circumvent that!
They come from all sides, and you need a place to take cover.
The moat area near the airplane is a great place for camping.
After you get the confirmation that you gave the right engine, you can escape with the airplane
(if you found the keys on the table in day 1) or you can escape with the chopper.

I hope I could help you with this guide so you can enjoy the heist as much as we do!

Big thanks go out to Craylink, KWAID, Cuenoa and Zodan for trying hard
to solve the puzzle and to Amixtra, who corrected my terrible english!

Overkill, thank you so much for such an amazing heist!
We love secrets.
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Fergus Mar 20 @ 11:57pm 
i need walter for this shit
[tks] LtKaiden Mar 16 @ 2:10am 
thx, lifesaver mate.
Darthpizzaroll Jan 1 @ 11:33pm 

It means the engine only has 1 cable.
iibeohC Dec 8, 2014 @ 12:28am 
but there is this thing H then a infinite sign below what does that mean?
MrLeafZONE Dec 7, 2014 @ 6:11am 
Thanks for the help
[ILL1] Docteur.Stup Nov 30, 2014 @ 11:21am 
Are you kidding me, how many body bags you have on day 1 ?
Gnorrk Nov 18, 2014 @ 10:52am 
henza Nov 18, 2014 @ 2:01am 
This guide's a life saver! great work
Rokk Nov 5, 2014 @ 11:51am 
Could you perhaps show us some locations where the clipboards can be?
Doctor Sky Sep 8, 2014 @ 9:41am 
Firing an unsilenced weapon/saw will alarm the police, even if all enemies on the map are dead.