Hondata Intake Manifold Gasket (IMG) Installation on the Acura RSX (K20)
Introduction
The factory intake manifold gasket on the aluminum-manifold K20 (Acura RSX, including the Type-S) is a thin metal piece that readily conducts engine heat into the manifold, warming the intake charge. Replacing it with the thicker, insulating Hondata gasket reduces that heat transfer and helps recover power lost during hot-weather or stop-and-go driving; the effect is most pronounced on the all-aluminum Type-S manifold and smaller on the base car's plastic manifold. The job is a straightforward parts swap in principle, but access to the lower manifold bolts is tight and the throttle body must be moved aside to reach them, so patience and the right extensions matter more than mechanical skill. No cooling-system drain is needed and the lower support bracket stays in place. Adapted from a community writeup by victor.s on Club RSX (https://www.clubrsx.com/threads/hondata-intake-manifold-gasket-install.189437/), including corrections from the follow-up discussion.
Reference
Tools Required
- Ratchet set with 10mm and 12mm sockets
- 12mm deep socket
- Socket extensions (3", 6", and 10")
- Universal-joint (swivel) socket adapter
- 12mm wrench
- Phillips or flat-blade screwdriver (to release the intake)
- Torque wrench
- Soft/rubber mallet (to break the throttle-body seal)
- Long needle-nose pliers
- Magnetic bolt retriever (recommended)
- Shop rag
Parts Required
-
Hondata intake manifold gasket (IMG)
Safety Warnings
- ⚠ Torque the manifold and throttle-body bolts to 16 ft-lb. Over-tightening has cracked and warped owners' aluminum manifolds; this corrected value comes from the follow-up replies.
- ⚠ Work only on a fully cooled engine to avoid burns from the hot manifold and throttle body.
- ⚠ The throttle-body coolant hoses remain connected during the job; support the throttle body and do not yank on the hoses.
- ⚠ Reconnect every sensor and electrical connector before starting the engine to avoid triggering a check-engine light.
Step-by-Step Instructions
1 Let the engine cool completely
Park the car and allow the engine to return to ambient temperature before beginning. A hot manifold and throttle body are difficult and unpleasant to handle, and everything comes apart more easily cold. There is no need to drain the coolant for this procedure.
2 Remove the engine cover
Open the hood and take off the plastic trim panel over the manifold (the one labeled i-VTEC) by unthreading its two retaining bolts with a 10mm socket. Set the cover and its hardware aside.
3 Remove the intake assembly
Detach whichever intake is fitted, whether the factory airbox, a short-ram, or a cold-air setup. A screwdriver handles the clamp or bracket fastener; the exact type depends on your intake. Clearing the intake opens up working room around the throttle body.
4 Detach the throttle body
The throttle body is fastened to the manifold with two nuts and two bolts. Remove all four using a 12mm socket on a 3-inch or 6-inch extension. Unplug the electrical connectors so the unit can be moved freely. Leave the coolant hoses attached; they only need enough slack to let the throttle body swing aside, so they do not have to come off.
5 Break the throttle-body seal and swing it clear
The throttle body is usually stuck to the manifold by its gasket. Rest a soft mallet or other non-marring tool against it and tap to crack the seal rather than trying to wrestle it loose by hand. If it catches on the remaining studs, rotate the lower coolant fitting so its clamp bracket clears the way. Place a rag between the throttle body and manifold to protect both sealing faces, and support the unit so its still-connected coolant hoses are never strained.
6 Remove the manifold support braces
Two metal braces that the engine cover was bolted to remain on the manifold. Unbolt them (a 10mm or 12mm socket fits, depending on the fastener) and set them aside. The lower support bracket beneath the manifold stays in place: it does not need to come off to change the gasket, and removing it is far more trouble than it is worth.
7 Remove the five manifold bolts
Five bolts hold the manifold to the head: two across the top and three along the bottom. Start with the two upper bolts and the lower-left bolt using a 12mm socket on a 6-inch or 10-inch extension. For the bottom-center and bottom-right bolts, add a universal-joint adapter and reposition the throttle body to find a workable angle. The bottom-right bolt is the most awkward of the group. Work carefully, because a bolt dropped into this area is hard to recover; a magnetic retriever is worth keeping on hand.
8 Back out the two upper studs
Two studs remain at the top. Spin their nuts off with a 12mm deep socket and extension. To extract each stud, thread one nut on reversed and a second nut on normally, then tighten the pair against each other until their faces lock together. Turn the reversed nut counterclockwise with a 12mm wrench to walk the stud out. If both nuts merely spin while the stud stays put, they are not clamped tightly enough against one another; snug them harder and try again. Leave the nut pair on each stud so you can drive it back in during reassembly.
9 Remove the old gasket
With all five bolts and both studs out, ease the manifold back from the head. A helper makes this much easier: one person holds the manifold away while the other frees the thin factory gasket with needle-nose pliers and a flat screwdriver. Note precisely how the original sits before pulling it out so the replacement can be installed the same way.
10 Install the Hondata gasket
Fit the Hondata gasket in the same orientation as the one you removed. Guide it into place and align its bolt and stud holes; passing a small screwdriver through the holes helps register everything correctly. Once the holes line up, the manifold is ready to be drawn back against the head.
11 Reassemble and torque to specification
Reverse the teardown: drive the studs back in and remove the double-nut pairs, refit the five manifold bolts, reinstall the braces, reseat the throttle body, and reconnect the intake. A new throttle-body gasket is not required; the original is reusable. Tighten the manifold and throttle-body fasteners to 16 ft-lb using a torque wrench rather than by feel. This corrected value comes from the follow-up discussion, and exceeding it can crack or warp the aluminum manifold.
12 Reconnect everything and verify
Before cranking the engine, confirm that every electrical connector and coolant hose disturbed during the job is reattached; a forgotten sensor plug is the usual cause of a check-engine light afterward. Start the car, let it idle, and check for a steady idle with no warning lights. After a short drive the manifold should feel noticeably cooler to the touch than it did with the factory gasket.
Pro Tips
- 💡 If a coolant hose will not release, push it off instead of pulling: work a flat screwdriver under the end to break the seal, and twist the hose with pliers to unstick it from the fitting before pushing it free.
- 💡 A magnetic bolt retriever guards against losing a dropped manifold bolt deep in the engine bay.
- 💡 If the underside braces are too hard to reach, removing the upper radiator support can open up enough room to get a socket on them.
- 💡 No coolant drain is needed, and the lower manifold support bracket can stay bolted in place throughout.
- 💡 Bypassing the throttle-body coolant loop is optional and debated: it can slightly lower intake temperature but has caused rough idle for some owners in cold, damp weather. Only reroute those hoses if you understand the tradeoff, and in cold climates leave them connected.
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