Acura RSX Energy Suspension Motor Mount (ESMM) Insert Install
Introduction
Energy Suspension motor mount (ESMM) inserts are polyurethane fillers that pack the voids in the factory front and rear mount bushings, stiffening the link between the engine and subframe. The payoff is less fore-and-aft engine movement and noticeably reduced wheel hop off the line, at the cost of some extra cabin vibration. This guide covers the 2002-2005 Acura RSX and RSX Type-S (Honda Integra DC5) and centers on the garage-friendly subframe-drop approach: rather than unbolting the front mount from the block, whose three bolts are notorious for stripping, you loosen and tilt the subframe down to reach each mount in place. Budget a couple of hours, longer if a race header has to come off first, and work only on a car held up by jack stands. The rear mount is the fussiest part of the job, so leave yourself time and patience for it. Adapted from a community writeup by Randeezle on Club RSX (https://www.clubrsx.com/threads/official-esmm-install-guide-20-steps.269589/), including corrections from the follow-up discussion.
Reference
Tools Required
- Floor jack
- Jack stands (rated for vehicle weight)
- 1/2-inch drive ratchet or breaker bar
- 17mm socket (subframe and mount bolts)
- 14mm socket (sway bar bushing bolts)
- 12mm socket, deep 12-point preferred (exhaust spring bolts)
- Flat-head screwdriver (to wedge/align the rear mount)
- Penetrating oil / liquid wrench
- Optional: silicone or wheel-bearing grease for the bushings
Parts Required
-
Energy Suspension motor mount insert kit (ESMM) - 4 polyurethane inserts, 2 for the front mount and 2 for the rear (fits 2002-2005 RSX)
-
Optional: bushing grease (roughly $13 CAD for 8 oz)
Safety Warnings
- ⚠ Support the car on jack stands and never work under it on the jack alone; the suspension must hang freely, so ramps are not an option here.
- ⚠ Keep your eyes and mouth clear when releasing the wheel-well clips, as road grime falls out when they let go.
- ⚠ Solid inserts increase noise, vibration, and harshness; this is expected, not a fault.
Step-by-Step Instructions
1 Raise and support the front of the car
Lift the front with a floor jack and set it on jack stands rated for the weight. The front suspension must hang unloaded, so ramps will not work for this job; the subframe can only droop away from the body once the wheels are off the ground. Give yourself enough clearance to reach the mounts and swing a ratchet underneath.
2 Release the wheel-well clips and free the undertray
Pop the plastic fasteners holding the front section of the undertray, concentrating on the two clips tucked up inside each wheel well; those are the ones that let the panel drop away with the subframe later. Turn your face away as you release them, because accumulated road grit tends to fall out. The rest of the tray can stay attached.
3 Break the exhaust loose at the header
Undo the two spring-loaded bolts (12mm) that join the header to the downpipe/cat so the exhaust can shift aside later. Soak them first with penetrating oil, as they are commonly seized. A deep 12-point socket reaches the more buried of the pair, and a few firm tugs should crack it free. If a one-piece race header is fitted there are no spring bolts; instead loosen the five bolts securing it to the cylinder head so it can drop far enough to clear the rear mount bolt.
4 Loosen the subframe bolts
Back the rear subframe bolts (17mm) out roughly three-quarters of the way but leave them threaded in. Use a 1/2-inch drive ratchet or a breaker bar here; a 3/8-inch drive is easily overwhelmed by how tight these are. Penetrating oil and steady pressure help with any that are corroded.
5 Drop the front of the subframe
From below, remove the through-bolt in the front mount (17mm), then take the two front subframe bolts out completely. The front of the subframe now tilts down at an angle, carrying the loosened undertray with it, and cannot fall on you because the rear bolts still hold it. If it barely moves, the rear bolts are not loose enough; back them out further until the front swings down and the mount is exposed.
6 Seat the front mount inserts
With the front mount open, press the two polyurethane halves into the gaps on the left and right of the bushing. Orient each front insert so its thicker, longer end points downward. The inserts are dense, so pinch them together with your fingers as you guide the subframe back up; a light smear of grease makes them slide in more willingly, though it is not strictly required.
7 Reattach the front mount and refit the clips
Push the subframe back into position, reinsert the front mount through-bolt and tighten it. Refit the wheel-well clips now rather than at the end, since they are easy to lose or crush underfoot once you move on. Thread the two front subframe bolts back in only about a quarter of the way for now, then snug the rear subframe bolts down.
8 Swing the sway bar down
Remove the four bolts (14mm) that hold the sway bar bushing brackets and let the bar drop out of the way. This opens up access to the rear mount and the long bolt that passes through it.
9 Free and drop the rear mount
With the exhaust now loose, nudge the downpipe aside and remove the rear mount bolt; it is noticeably long, which is why the exhaust has to move first. Then take out the rear subframe bolts so the back of the subframe tilts down the same way the front did.
10 Fit the rear mount inserts
Peel off the thin rubber flap that covers one side of the rear mount; it serves no purpose here. Press the rear inserts into place. They are symmetrical, so if one resists going in, swap the two around and try the other orientation.
11 Realign and reinstall the rear mount bolt
The rear mount's bolt hole sits off-center, and coaxing it back into line is the trickiest part of the whole job. Start the bolt in a short way, then wedge the mount upward with a screwdriver or the bolt tip while pushing up on the subframe with your forearm to bring the holes into register. If it will not line up, the front subframe bolts may be sitting too high and pulling the hole forward, so make sure they are loose enough; a floor jack under the subframe can also nudge it into place. It takes some trial and error, but it will seat.
12 Reassemble everything and lower the car
Swing the sway bar back up and refit its four bushing bolts. Run all four subframe bolts home and tighten the fronts and rears fully, then lower the car off the stands. Expect a firmer, more direct engine feel and much less wheel hop when launching, along with a bit more vibration; nudging idle up a couple hundred rpm smooths that out if it bothers you.
Pro Tips
- 💡 Soak every fastener in penetrating oil and keep a breaker bar handy; the subframe and exhaust bolts are notoriously tight and often rusted.
- 💡 Drive the subframe bolts with 1/2-inch drive sockets, not 3/8-inch, which tends to get overpowered.
- 💡 Bushing grease (silicone or an ES-type, about $13 CAD for 8 oz) is optional but eases insert fitment and may help the bushings last.
- 💡 Alternative approach: instead of dropping the subframe you can unbolt both mounts entirely and swap the inserts, pulling the battery and battery tray so a breaker bar can reach two of those front fasteners from above. The tradeoff is that the front mount's three bolts are the ones prone to stripping, which the subframe-drop method sidesteps.
- 💡 The 2002-2004 inserts also fit the 2005 RSX, as the mount pattern is unchanged. Note that the separate Ingalls torque damper is NOT listed for the 05 Type-S, so do not assume the damper carries over just because the mounts do.
- 💡 Telling the mounts apart: the front one resembles a 'U' marked with a single central dot, while the rear looks like a big 'U' with a little 'u' nested inside it.
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