Toyota 2.5L (152 cu in) I4 firing order — diagram & guide

As one of the last resorts of a four-cylinder naturally aspirated engine, Toyota developed a 2.5-litre AR-FE motor for the base models of its passenger cars. Turbocharged engines followed right after, so this one is special in many ways and one of them is surely the longevity and reliability.

If you are a proud owner of a car with this engine, the least we can do to help you keep it this way is to guide you on the Toyota 2.5L (152 cu in) I4 firing order. We’ve got a lot of things to address, starting with the firing pattern of the engine and its cylinders, and moving on to the differences compared with a 2JZ engine of the same capacity, so let’s get to it.

Toyota 2.5L four-cylinder firing order

First, let’s focus on the most important thing – the Toyota 2.5L four-cylinder firing order is 1-3-4-2. This is a common thing for Toyota’s four-cylinder engines, so it’s easy to lean back and say that’s it, the problem is solved.

However, we’ve seen where the confusion comes from regarding the drivers’ inquiries related to this engine. There’s another 2.5-litre engine with a 2JZ codename, and that’s where all the mess comes from. The best thing we can do to help you differentiate between the two is to get into the specs, and the key difference is that the 2JZ is a six-cylinder one.

So, it has the firing order 1-5-3-6-2-4, so you can probably see the major difference between these two engines. As long as you are certain that your car uses a four-cylinder one, you’ll be all right in terms of maintenance by using the firing order outlined above.

Toyota 2.5L cylinder diagram

The next important thing is to determine the cylinder pattern of the engine so you can focus on using the firing order to its fullest. This means checking each cylinder one by one through the firing order, so it would mean finding the first cylinder and then proceeding to check the cylinder number 4.

Well, at least that is easy with this engine since it’s a four-cylinder and the first cylinder is at the front of the engine on the left side if you are standing right in front looking at the engine. The cylinders go from 1 to 4 in a straight cylinder configuration, which is what makes it so simple to apply the firing order.

Toyota 2.5L four-cylinder vehicle applications

To help you diagnose misfires and replace the spark plugs and coil packs, we’ll also give you a full list of cars that use this engine. This should make it easier to avoid confusion with the 2.5-liter 2jZ, so here’s what it looks like:

• Toyota Camry
• Toyota RAV4
• Toyota Vellfire
• Toyota Avalon Hybrid
• Toyota Crown

The same engine has also been used in the Scion TC and a few Lexus models including the GS300h, IS 300h, and RC300h.

Our take

Well, that settles it for our guide on the Toyota 2.5L four-cylinder firing order. Thanks to this guide, we hope that you will be able to properly maintain the engine and keep it running for a while longer.

Just make sure that you’ve used the proper firing order compared to the 2jZ engine, and you’ll be good to go.