About 6 months ago I started noticing that I had a significant shimmy whenever I was stopped with the car in drive, such as stoplights, parking spaces, etc. I took a look under the car and found some rotted vacuum lines and promptly replaced them, expecting that to solve the issue, but it didn't.

I troubleshot the system per the mechanic's guide and believed the Engine Mount Control Solenoid Valve needed a replacement, especially after I discovered that the valve wasn't fully intact (I bought it with 90K in 2007). The top portion of the valve (looks like a small rubber cork) had never been in place from the day I bought it.

This still hasn't seemed to fix the issue. The front and rear mounts are about 3 years old, and I replaced them myself. I don't suspect the mounts because as soon as I apply gas and begin rolling, the car feels normal again. I'm talking only having rolled about a foot before it feels fine.

I've followed the troubleshooting guide and it suggests replacing the control solenoid valve. But I just replaced it 6 months ago. Does anyone suggest checking something else before replacing, again?

 

If the mount's vac control solenoid and hoses were recently replaced, that's hardly the problem. Try plugging the vac line for the solenoid and see if it helps.

Could very well be another issue affecting the low speed idle quality. Things such as a dirty TB intake, IAC valve, or clogged EGR passageways can also cause idle problems. Any "CEL" codes ?

 

No codes and EGR valve/ports are clean and clear. Not sure about the throttle body but it has been cleaned by me several times in the past.

I'll take a look at the IACV. When I troubleshoot, I do get differences in idle roughness when I plug the vac line for the solenoid (this is the line that runs from the solenoid to the upper manifold, right?)

 

Yeah, ya have vac to the solenoid valve. The valve is activated by the computer depending upon the conditions for which it was programmed. Sometimes the Acura technology went a bit too far for a vac assisted smooth ride. Hydraulic mounts are rather common in new cars, but many performance enthusiasts prefer solid mounts.

 

never trust new parts or labor- even your own,,or especially your own!

vac leak at motor mounts-front rear been vac pump/gauge tested?
recheck all the new lines, never know what happens between intent and installation
happens to the best~
You stated lines were rotten so maybe a hidden one is still leaking?

side note: ck the PCV valve- been several ziners with probs related to its clogging and the ball inside sticking,,not really your situation but Im trying to get the word out

 

Make sure the bolts are torqued and nothing is loose.
Also check if theres actually vacuum at the hose of the front mount while the engine is at idle 750-800 RPM.

 

Sorry to dig up old thread. Did you resolve issue OP? Kind of in the same boat with my 04 TL. Car droned and vibrated bad when I got it, replaced all motor/trans mounts with super cheap ones and had some vibration at idle. Replaced them with OEM and anchor and didn't make much difference. A control valve not operating correctly makes sense