On 4 wheel drive models, a groaning noise from the rear differential heard while going through turns can be caused by differential fluid break down. Servicing the rear differential will generally correct this concern.Google+
Car Problem Reports
Honda Element Groaning Noise on Turns Due to Differential Fluid Breakdown
Honda Element Problem
Drive Trains Affected: 2WD, 4WD, Automatic Transmission, Manual Transmission
Average Mileage: 80,827 mi (33,000 mi - 150,000 mi)
Visitor, 2004 Honda Element, 2WD
same problem, groaning noise
Visitor, 2006 Honda Element, 4WD, 60,100 mi
Groaning noise when turning
Loud grinding noise when turning left or right...mostly right hard turns...change differential fluid myself and it stopped for about 3 or 4 days...then it started up again. Will drain the differential Dual Pump II fluid again and add another qt.
Visitor, 2007 Honda Element, Manual Transmission, 46,000 mi
Makes noise during sharper turns. Today Honda suggested new differential fluid.
Visitor, 2004 Honda Element, 4WD, 97,000 mi
My dealer changed the rear differential fluid, that fixed it but is only a short term solution.
Groaning noise when turning at low speeds
Visitor, 2004 Honda Element, 4WD, 85,000 mi
squeaking/groaning noise at low speeds and on turns. Mechanic changed out the differential fluid seems to have fixed the problem... well mostly still happens some but very infrequently and not as loud.