JLT Oil Catch Can Separator Install and Review for 5th Gen 4Runner

JLT Oil Separator Install and Review for 5th Gen 4Runner

JLT Oil Separator and Catch Can – Complete Step By Step Install and Review

What is the purpose of an Oil Separator you ask?

To understand what we need to understand why. When the engine goes through the suck, squeeze, bang, blow cycle process, that’s known as the “combustion cycle”. With this combustion cycle, combustion gasses, gas, and oil get passed over the piston rings and into the crankcase.

This phenomenon is known as “blow-by” or blow-by gases. Now the pressure will eventually build up in the crankcase from the blow-by, and eventually, this pressure will have to be vented somewhere and this is where the Positive Crankcase Ventilation (PCV) valve comes in.

The PCV valve vents the blow-by from the crankcase into the intake manifold to be fed back into the combustion chamber to be burned off. The PCV valve does this so that these blow-by gases don’t mix with the oil, causing sludge build-up and oil degradation over time. One of the problems with the PCV system is that the oil and unspent fuel will eventually build up in the intake valves and over time reduce engine efficiency. Basically, the PCV valve doesn’t catch everything. It’s designed to catch a lot of blow-by gasses but misses quite a bit over time.

This is where the JLT Oil Separator comes in.

JLT Catch Can Install and Overview

JLT 3.0 Oil Separator

JLT Oil Separator for 5th Gen 4Runner

The JLT Oil Separator sits between the PCV valve and the intake manifold. It consists of two parts: the filter housing and the oil catch can.

JLT Oil Separator Features

  • 3oz capacity
  • Machined from billet aluminum
  • Multi-stage filter system
  • Made in the USA

The filter housing filters the blow-by from the PCV valve through a fine mesh stainless steel screen that traps the oil vapor so it condenses into tiny oil droplets and in turn gathers into a bigger droplet in an aluminum honeycomb filter below.

Once the droplets are large enough, it then falls into the oil catch can. Meanwhile, the gasses from the blow-by are passed back into the intake manifold without the sludge building oil and fuel.

What’s in the Box?

JLT Oil Separator What's Included for 5th Gen 4Runner

What’s Included

  • JLT Oil Separator (aka catch can)
  • Mounting bracket and M4 screws
  • PCV valve hose (Long)
  • Intake manifold hose (Short)

Find it Online:

Tools & Materials:

Step 1. Remove Plastic Engine Cover

Toyota 4Runner 4.0L Engine Cover

Pretty simple start, lift up on the plastic engine cover and then pull it towards you.

Step 2. Locate and Remove the PCV Hose

5th Gen Toyota 4Runner PCV Hose

With the cover removed, locate the PCV hose on the driver’s side of the engine. The PCV hose is connected to the intake manifold and the PCV valve on the valve cover. Locate the two spring clips at both ends of the hose and slide them towards the center of the hose. Once the spring clips are no longer clamping down on the connectors, gently pull and remove the hose from their connectors.

5th Gen Toyota 4Runner PCV Hose on Driver Side Valve Cover

The PCV valve on the valve cover is harder to get to, but if you follow the hose from the intake manifold side, it should be right there.

Step 3. Install PCV Valve and Intake Manifold Hoses

5th Gen 4Runner PCV Hose Removal

Remove both spring clips from the PCV hose and transfer them to the short section of the PCV Valve Hose and Intake Manifold Hose.

5th Gen 4Runner 4.0L PCV Hose Location

Starting with the PCV Valve Hose (Long) route the hose from back to front and connect the short end of the hose to the PCV valve. I put blue painter’s tape on the PCV Valve Hose to make identifying the hoses easier. Then, lightly grease the intake manifold connector.

Route the Intake Manifold Hose (short) from back to front and connect the short end of the hose to the intake manifold connector. I found the intake manifold connector was the more difficult one to insert, greasing the connector really helped.

JLT Oil Separator PCV Hose Install for 5th Gen 4Runner

The other end of the hoses should come out next to the oil cap.

Step 4. Install JLT Oil Separator and Bracket

JLT Oil Separator Bracket Install for 5th Gen 4Runner

Using a 10mm extended socket and ratchet, remove the ball stud from the intake manifold.

JLT Oil Separator Install and Lube for 5th Gen 4Runner

Lightly grease the two connectors on the JLT Oil Separator

JLT Oil Separator Hose to Intake and From PCV Install

Connect the PCV Valve Hose to the “J” side of the Oil Separator.

JLT Oil Separator Install Bracket for 5th Gen 4Runner

Connect the Intake Manifold hose to the “T” side of the Oil Separator. Next, mount the Bracket to the JLT Oil Separator using the 2 M4 screws. And finally, using the previously removed ball stud, mount the Bracket onto the Intake Manifold. Do not fully tighten the ball stud.

Step 5. Position JLT Oil Separator

JLT Oil Separator Install for 5th Gen 4Runner

Reinstall the engine cover and position the Oil Separator so the engine cover doesn’t excessively push down on the bracket and oil separator. Once you have the position figured out, check and make sure that the bracket isn’t hitting any hoses, and then tighten down on the ball stud by hand.

The engine cover will rest on the top of the Oil Separator Bracket and according to JLT, this is normal.

Final Thoughts

5th Gen 4Runner Oil Catch Can Install on 4.0L

Oil separators and catch cans in general are one of those modifications that don’t really have a downside. It will keep oil and unspent fuel out of your intake manifold and maintain engine efficiency. An oil separator is definitely a good modification to invest in if you plan on keeping your 4Runner for miles to come.

Check back for an update after 3,000 miles to see how much oil has been accumulated.


JLT Oil Catch Can Separator Install and Review for 5th Gen 4Runner

@ +1,214 miles: The catch can collected 0.6 oz of oil/fuel.

@ +2,005 miles: The catch can collected 1.1 oz of oil/fuel.

@ +3,278 miles: The catch can collected 1.8 oz of oil/fuel.

*Always recycle used motor oil accordingly.

JLT Oil Catch Can Separator Install and Review for 5th Gen 4Runner

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3 months ago

I installed one a few months back. Didn’t expect it to fill up so fast. After remembering to check after two months it was full to the top. Checked it again after 3 weeks and it was already halfway full. Granted, I do put a lot of miles on.

7 months ago

I installed this a while back and have noticed a number of improvements after putting a fair number of miles. First, I’ve noticed better gas mileage in the city. The overall power and throttle response seems to have improved. My truck feels more responsive. The stance, and the lift have also improved as well as the overall off road capability. It handles much better on the trails and washboards. I was thinking about re-gearing my truck but this upgrade basically negated that need.

Brenan Greene(@brenan-greene)
5 months ago
Reply to  OverlandingUSA

The stance, and the lift have also improved? With a catch can???

Angel Garcia
Angel Garcia
7 months ago

I have just ordered mine. I do have a couple questions.
1. How often do you check the catch can? 2. What do you do with the oil that is in the catch can when you empty it?


7 months ago

Seems like an answer to a problem no one is having.

7 months ago

The PCV system is there to help protect the environment. Using this system defeats that purpose. If you do use this system, please dispose of the waste responsibly.

7 months ago
Reply to  RayC

Preach to China and India. Most Americans are responsible.

David M Williams
David M Williams
7 months ago

I did a similar thing on an exotic engine and had “mayonnaise” build up on the lines, how are the lines doing on yours in that 3k, and build up on the tubes?

Chris K
Chris K
8 months ago

Thanks for posting, I bought one and can’t wait to install it. I’ve been debating getting one for a while.

8 months ago

Says they wont even ship to a CA address… bummer….

8 months ago

The only downside is that if you live in California this can cause you to fail smog due to tampering with the emissions system. That is the only reason I haven’t installed one on my 4runner

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