Intake Manifold Gasket replacement / Radiator Flush

[Ace03corolla08sienna]

I have a 2003 Corolla and recently replaced intake manifold gasket to resolve an idle issue (one that seems to plague many with 9th gen corolla's). I have limited experience and only had the TSB as a reference for the repair, which didn't help nearly as much as I'd hoped. So I decided to take pictures to show my experience and help others. FYI - I also flushed my radiator at the same time being that it needed it and the TSB called out to drain the fluid anyway.
The Intake Manifold cost me $11 from O'Reilly Auto as I wanted it next day, otherwise it would have cost $6.

I started by draining the radiator. I waited until I was confident the engine had cooled down enough to remove the radiator cap:


The drain plug on my 2003 Corolla is located driver side/engine side contrary to what I've read elsewhere, it's basically a little plastic winged screw that I could screw/unscrew with my hands:



I just stuck a small container underneath to catch most of the coolant/water:


Next I removed the large air hose:



Removed the engine cover on top, 2 black tabs and 2 screws (10mm socket) (I accidentally broke off the black tabs!)



There are 4 or 5 hoses coming to/from the throttle body (on left in picture) that I removed. I removed as many as I could to clear the way when I needed to lift the intake manifold:





There were also 1 or 2 wires that I needed to unclip from the throttle body:


I unclipped the big wiring harness, 2 clips:

Using a screwdriver:

And unclipped a couple more clips holding the wire harness:


Now there was access to the nuts and bolts holding the intake manifold in place:

I think there 2 nuts and 5 bolts (including the bolt holding the throttle body). Using a 12mm socket did the trick on all these:




Now I could pull the manifold away to expose the gasket!:


I was unable to get a couple of the hoses off the throttle body so I simply tilted the manifold as needed to get to the gasket:



I definitely needed to clean things up after removing the old gasket and prior to installing the new gasket:



Installed new gasket:


From here I simply worked backwards, bolted everything up and put hoses back the way they belonged.
I then moved on to finishing the radiator flush and fill...
I left the hose shown below unclipped, it's on the drivers side/engine side towards top of radiator:


With the drain plug in, and the hose unclipped as previously mentioned, I filled the radiator with distilled water until it was coming out clear from this hose:



Next I removed the drain plug again to empty everything out:


Once again screwing in the drain plug, I filled the radiator with distilled water until it started coming out the upper hose, at which point I opened up the drain plug to empty it.
I screwed in the drain plug for the last time and clipped the hose back in place. The Corolla repair manual I have states a capacity of 6.5 liters (6.9 US qts, 5.7 lmp. qts). I found this not to be true unless I did something wrong. I was just going to use a gallon of coolant and 3/4 gallon distilled water to have a good ratio. It did not take nearly this much before being completely full, even filling the reservoir. Maybe somebody else can shed some light on this? This completed everything!
The idle great now, runs well. Engine light has not come back on after resetting it.

[invader]

You should've got Toyota's new revised intake manifold gasket. # 17171-22030 List Price: $7.78
Your Price: $5.84 Shipping in USA: $8.50: https://www.cstoyotaparts.com/oemtoyotaparts.html

There was no need to drain the coolant since you were able to replace gasket without removing throttle body. You were able to do it without even seperating the throttle body from the intake manifold. Although there's no need for it, you could remove coolant lines from the throttle body to remove it, without losing much coolant when engine is cold... I bypassed my throttle body coolant lines.
You're supposed to also drain the engine block by opening the valve at the back to get all the coolant out, as stated in service manual.

[Phlingwinger]

Good day! (well, not for me...)
I had this comparable low idle problem, read this posting, and decided to give this fix a shot. Long story short, my 04 rolla now runs very hard at idle. I followed the steps listed above, with the exception of draining the coolant. I used a small amount of CRC throttle body cleaner to clean up the mating surface of the engine and the intake manifold, and torqued my bolts in a diametrically opposing fashion. On initial start up the car turns over and fires, but then the idle drops down, and after about thirty seconds the engine finally stalls. I only disconnected the hoses on top of the throttle body and the main feed from the air filter box. They are all back in place, and I did not disconnect any of the electrical plugs on the throttle. At the exhaust pipe it sounds almost like there is a small misfire occuring...
What could I have possibly screwed up?

[Ace03corolla08sienna]

Originally Posted by invader

You should've got Toyota's new revised intake manifold gasket. # 17171-22030 List Price: $7.78
Your Price: $5.84 Shipping in USA: $8.50: https://www.cstoyotaparts.com/oemtoyotaparts.html

There was no need to drain the coolant since you were able to replace gasket without removing throttle body. You were able to do it without even seperating the throttle body from the intake manifold. Although there's no need for it, you could remove coolant lines from the throttle body to remove it, without losing much coolant when engine is cold... I bypassed my throttle body coolant lines.
You're supposed to also drain the engine block by opening the valve at the back to get all the coolant out, as stated in service manual.

Invader,

I needed to do a radiator flush anyways so I thought I'd take care of both at the same time. Thanks for the heads up on the valve at the back, I was unaware of this.

[Ace03corolla08sienna]

Originally Posted by Phlingwinger

Good day! (well, not for me...)
I had this comparable low idle problem, read this posting, and decided to give this fix a shot. Long story short, my 04 rolla now runs very hard at idle. I followed the steps listed above, with the exception of draining the coolant. I used a small amount of CRC throttle body cleaner to clean up the mating surface of the engine and the intake manifold, and torqued my bolts in a diametrically opposing fashion. On initial start up the car turns over and fires, but then the idle drops down, and after about thirty seconds the engine finally stalls. I only disconnected the hoses on top of the throttle body and the main feed from the air filter box. They are all back in place, and I did not disconnect any of the electrical plugs on the throttle. At the exhaust pipe it sounds almost like there is a small misfire occuring...
What could I have possibly screwed up?

Phlingwinger,

I'm sorry to hear about this being unsuccessful, did you find any resolution? Did everything get reassembled correctly?

[Ohiowa]

Originally Posted by Phlingwinger

Good day! (well, not for me...)
I had this comparable low idle problem, read this posting, and decided to give this fix a shot. Long story short, my 04 rolla now runs very hard at idle. I followed the steps listed above, with the exception of draining the coolant. I used a small amount of CRC throttle body cleaner to clean up the mating surface of the engine and the intake manifold, and torqued my bolts in a diametrically opposing fashion. On initial start up the car turns over and fires, but then the idle drops down, and after about thirty seconds the engine finally stalls. I only disconnected the hoses on top of the throttle body and the main feed from the air filter box. They are all back in place, and I did not disconnect any of the electrical plugs on the throttle. At the exhaust pipe it sounds almost like there is a small misfire occuring...
What could I have possibly screwed up?

I just completed mine on Sunday and disconnected all hoses but the coolant lines from the throttle body. Put it all back together and it runs like a champ. I just used isopropyl alcohol to clean the mating surface.

Unless you misplaced a line when reconnecting them, the alcohol seems to be the only difference.

Did you torque to Toyota specs (22lb. ft.)?

<EDIT>
While I had the manifold off and had access, I took out the OCV strainer and cleaned it. After 99,000ish miles, it wasn't clogged at all. Cleaned it with some carb cleaner, let it dry and put it back in. Better to do it during this job than have to take off the alternator and accessory drive belt to do it later (assuming of course that you need this repair in the first place).
</EDIT>