DIY: 04-07 STi (includes 02-07 Wrx/04-08Fxt using a STI TMIC) top mount intercooler removal. Take it off baby!

Now that you have your little turbocharged wonder… What will you do with it? Drive it gingerly? Leave it in the garage waiting for it to go up in value? Take every part off of it to see what lies beneath? Yeah… let’s do that third one! It seems like every time I work on either of my cars I am taking my intercooler off for one reason or another.

The reason for your Subaru hood scoop! Feeding air across the intercooler to help lower the incoming air to the engine.

The reason for your Subaru hood scoop! Feeding air across the intercooler to help lower the incoming air to the engine.

Why would you remove it? Let’s explore a few reason you would…

Replacing your factory dog bone with an upgraded mount.

Upgrading your dogbone mount.

Upgrading your dogbone mount.

Checking your intercooler for oil in it to make sure of your turbo and engines health.

Replacing your turbo to intercooler hose, intercooler to throttle body hose, replacing your y-pipe gaskets, and many other items that reside below it.

Replacing the stock 90 degree hose.

Replacing the stock 90 degree hose.

Over time the factory rubber coupler will degrade and can crack and tear from years of use and removal/installation.

Over time the factory rubber coupler will degrade and can crack and tear from years of use and removal/installation.

Stock throttle body unit on the left and upgraded silicone Grimmspeed unit.

Stock throttle body unit on the left and upgraded silicone Grimmspeed unit.

Maybe you purchased a new intercooler and it is time for the old one to retire.

Lastly removing the engine or unbolting the trans is made that much easier by removing the intercooler.

Looking back through my pictures I only have two photos of the Forester with the original intercooler. Apparently, that shows my disdain for this part. The turbo coupler is a piece of plastic that doesn’t like to expand to fit the turbo, thus making it a nightmare to put on unless you have warmed it up recently. This was my main reason for changing it out.

Looking back through my pictures I only have two photos of the Forester with the original intercooler. Apparently, that shows my disdain for this part. The turbo coupler is a piece of plastic that doesn’t like to expand to fit the turbo, thus making it a nightmare to put on unless you have warmed it up recently. This was my main reason for changing it out.

And many more!

Cylinder 4 cooling mod by GetaDometune.

Cylinder 4 cooling mod by GetaDometune.


Tools

Now with those listed off let’s get down to business. Tools we will need for this project. A 3/8th ratchet with a 8 mm, 12 mm and 14mm sockets. A set of pliers can be helpful for stubborn breather hoses. An 3/8ths extension can also make this much easier. A 3/8th electric impact or ratchet can make this a much quicker job.

My go to socket set. I have used these for many years and have yet to have one fail on me. A few have been misplaced and replaced/

My go to socket set. I have used these for many years and have yet to have one fail on me. A few have been misplaced and replaced/

I honestly can’t think of the last job I completed without using this too. Milwaukee 3/8th impact, it is so dang versatile.

I honestly can’t think of the last job I completed without using this too. Milwaukee 3/8th impact, it is so dang versatile.

We will start by popping the hood and locating the top mount intercooler or tmic for short. Now we will start with the breather hoses. One trick to removing these easier is to take a long drive prior to removal and yet another is to use a small torch or lighter to warm them up to let them release that much easier!

08+STi intercooler on the Forester. Added to keep the upgraded VF39 turbo company.

08+STi intercooler on the Forester. Added to keep the upgraded VF39 turbo company.

Install


Looking around at the front of the intercooler you will see the bypass valve(bpv) that is secured by two 14mm bolts. If you are still rocking the stock bolts this is a great upgrade the Company 23 tmic stud kit! Now you will snag the bpv gasket before it gets lost on the top of engine.

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Set this gasket safely out of the way to keep it from falling on to the mess of hoses and cavities on the top of the engine.

Set this gasket safely out of the way to keep it from falling on to the mess of hoses and cavities on the top of the engine.

Now take the BPV and mov it towards the intake manifold. Keeping it out of your way when you go to pulling the intercooler out.

Now take the BPV and mov it towards the intake manifold. Keeping it out of your way when you go to pulling the intercooler out.

We can now head over to the throttle body and 90 degree hose. This is where your 8mm and extension/screwdriver will come in handy. I loosen all three hose clamps to help everything move freely when you start wiggling and fighting to free the tmic from its engine bay prison.

Hoses loosened on the throttle body hose.

Hoses loosened on the throttle body hose.

This is usually the placement of my 90 degree clamp. If you can position it here it will make easy to remove with a screwdriver or 3/8 ratchet.

This is usually the placement of my 90 degree clamp. If you can position it here it will make easy to remove with a screwdriver or 3/8 ratchet.

Preferred placement of the intercooler to throttle body couple. Driver’s side tucked down by the BPV(Bypass valve)

Preferred placement of the intercooler to throttle body couple. Driver’s side tucked down by the BPV(Bypass valve)



The last two bolts we have to remove are the mounting bolts that hold the tmic in place. Both of these will be 14 mm bolts and are located on far left and right of the intercooler. With those remove you can now begin the actually removal part.

Passenger side bolt. Located right above the turbo.

Passenger side bolt. Located right above the turbo.



Driver’s side bolt sometimes it is hidden below the lines that are off to the side.

Driver’s side bolt sometimes it is hidden below the lines that are off to the side.


Pushing/pulling the intercooler towards the windshield will release the tmic to throttle body hose. Moving to the driver’s side of the car you will gain a bit of leverage on the intercooler. Pulling it towards yourself and slightly upwards seems to be the best way to release the tmic from the engine bay. Setting it off to the side you can now pat yourself on the back and enjoy a beverage of your choice!

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Standing at the driver’s side just start pulling towards yourself. The 90 degree hose will slide right off.

Standing at the driver’s side just start pulling towards yourself. The 90 degree hose will slide right off.

You can now check the inside of the intercooler for oil. A slightly film of oil is a-ok but if you have oil dripping out of the intercooler you will need to check your turbo inlet tube and turbo for starters. Finding the source of the oil will help you figure out your issue. Otherwise, you can continue on to your further repairs or installations.

Looking into the hoses will show no oil, a light film of oil or fair amount of oil. Hopefully you will have a fairly clean intercooler.

Looking into the hoses will show no oil, a light film of oil or fair amount of oil. Hopefully you will have a fairly clean intercooler.

With this all complete you can now gaze upon your large open area covered with wires, hose and brackets. You can now replace the parts you have, add an aos or anything else that tickles your fancy. For those curious of how to easily reinstall your intercooler lets go ahead and get to it.


This is never an easy task. I honestly upgraded my Forester xt’s turbo and intercooler because the factory intercooler is so awful to put back on. Instead of a silicone hose you have a plastic fitting which after many years of heat cycles, with that the plastic shrinks down and is so hard to reinstall when cold. A protip for that are using a heat source to help the plastic relax prior to reinstalling it.



I always start on the driver’s side when installing my intercooler. Making sure to move you a/c lines and brake booster hose out of the way. It loves to move over the driver side mount causing you trouble when installing it. Now you will try to do your best to get the 90 degree hose to start it’s way on the coldside of the turbo.

This is my starting position. The 90 degree hose is aimed towards the turbo outlet and the throttle body hose is laying against the throttle body. Passenger side of the TMIC tilted down and the Driver’s side on top of the bracket.

This is my starting position. The 90 degree hose is aimed towards the turbo outlet and the throttle body hose is laying against the throttle body. Passenger side of the TMIC tilted down and the Driver’s side on top of the bracket.

Having the 90 degree hose starting on the turbo inlet, give the intercooler a push towards help slide it on. You may need to wiggle it back and forth but it should start to go on. If the 90 degree hose doesn’t fully engage the turbo outlet, use a 1/4 extension to push down any bunched up areas.

Not easy to see in this photo but the hose isn’t sliding right over. The bottom of it has caught on the lip of the turbo. Taking a small thin blunt tool(1/4th extension you can easily push the fold down and help it sit right.  With the 90 degree now sliding down the turbo inlet you can now stand in front of the tmic and start pulling the intercooler down on the throttle body. The same issue is common on the throttle body hose, it may not slide over the opening and bunch up below. Use the same technique to help it slide on.

Not easy to see in this photo but the hose isn’t sliding right over. The bottom of it has caught on the lip of the turbo. Taking a small thin blunt tool(1/4th extension you can easily push the fold down and help it sit right.

With the 90 degree now sliding down the turbo inlet you can now stand in front of the tmic and start pulling the intercooler down on the throttle body. The same issue is common on the throttle body hose, it may not slide over the opening and bunch up below. Use the same technique to help it slide on.

Both hoses now fully engaged on their outlets/inlets.

Both hoses now fully engaged on their outlets/inlets.

Now you will take the BPV gasket and replace it on the intercooler and add the bolts/nuts to bolt it on.

I can’t say enough about these Company 23 tmic studs. They make this job so much easier and you will no longer worry about stripping out the tmic aluminum threads for the factory bolts.

I can’t say enough about these Company 23 tmic studs. They make this job so much easier and you will no longer worry about stripping out the tmic aluminum threads for the factory bolts.

Bolting the Bpv down to move on to the tmic bracket bolts.

Bolting the Bpv down to move on to the tmic bracket bolts.

Now the only bolts that connect the tmic to the engine are ready to go on. Make sure to start these by hand, with the deep bushings and force exerted by the intercooler couplers it’s very easy to strip the threads out on one of these brackets. Once they have started run them down snugly.

Bolted up but left a bit loose to adhere the silicone couplers.

Bolted up but left a bit loose to adhere the silicone couplers.

Your final steps will be situating your clamps on the 90 degree hose and throttle body. Take care when locating the clamp making sure they are raised sections, also referred to as a bead, of either throttle body or turbo outlet. These will keep the hose on by not allowing the tightened clamp to slide off.

Shown above: The bead located on the throttle body and turbo help the clamps hold the silicone/rubber hoses on.

Shown above: The bead located on the throttle body and turbo help the clamps hold the silicone/rubber hoses on.

All done! You can now idle the car and double check your connections visually, while listening for whooshing/hissing air to signify leaks.

All done! You can now idle the car and double check your connections visually, while listening for whooshing/hissing air to signify leaks.

Congratulations, you have successfully removed and reinstalled your intercooler. Listening for air leaks and watching your idle for odd fluctuations. Time to celebrate with a short drive to check that everything is connected properly. These are key to identify that all your connections are tight and good to go.

Amazon links:

Generic colored 90 degree hoses

Grimmspeed Y-pipe and coupler kit

Subaru genuine throttle body hose 21869AA121

Subaru Genuine 90 degree coupler hose (No idea why this is $400

3/8th extension set

Dan EngstromComment