2007 IMPORT TECH REPORT

Motor,  Dec 2006  by Weissler, Paul

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The Fits on-board diagnostics include Hondas no-trouble-code algorithm to detect a carbonized throttle body. With your scan tool connected, run the engine at 3000 rpm no-load until the radiator fan comes on. Then let the engine idle and check the throttle position sensor, which should read under 2.6°. If it reads higher, the throttle body needs to be cleaned.

The engine block has a coolant drain plug, which is partly hidden by the oil filter. Even with the plug out and the radiator drained, it's a tough cooling system to empty-almost 30% of the coolant will remain in the system.

Power steering is fully electrical/electronic-no hydraulic pump or lines.

The CR-V sport/ute (and the mechanically similar Element) was redesigned completely for 2007, including the spare tire moved inside and the tailgate flipping up instead of opening from die side. The 2.4L dual overhead-cam Four remains the only engine, and although it's up 10 hp to 166 (161 ft.-lbs. of torque), its biggest change is the switch from a cable to an electronic throttle and retuning for a flatter torque curve. The 2.4 is a long-stroke engine (87mm bore x 99mm stroke), which contributes to good launch.

The engine mounting system also has been completely changed. Instead of four lower mounts (including the transmission mount) to the body and subframe, the 2007 model has an upper front torque strut (with integrated mount) attached to the body, a rear lower torque strut mounted to the subframe and a transmission mount. The torque struts are intended to reduce idle vibration and engine noises during acceleration.

The CR-V continues with its optional all-mechanical Real-Time 4WD system; there's not an electronic module in sight. The propeller shaft drives one oil pump, the rear axle drives another and the differential pressure modulates application of a multidisc clutch pack in the torque transfer coupling.

The Acura line adds the RDX, a new, smaller SUV apparently based on the same platform as the CR-V, but with Acura's first turbocharged/air-to-air intercooled engine. It's a 2.3L engine that produces 240 hp and 260 ftlbs. of torque, and although the bore and stroke are 87x89mm, the engine is a version of the 2.4L DOHC used in the CR-V

The turbo, which has a peak boost of 13.5 psi, is integrated with the exhaust manifold, which is bolted to the rear side of the transversely mounted engine. It's a variable-flow design (like many turbos), with a valve that partly restricts exhaust gas flow at low rpm, to accelerate flow to the turbo impeller, so it runs faster to reduce turbo lag. On cold starts, timing is retarded for emissions control, which also reduces engine vacuum (a real problem for braking, particularly at high altitude). So the car has an auxiliary vacuum pump connected to the brake booster.

The opening above the Acura badge is functional; it's the air inlet to the turbo.

Acura's latest Super-Handling AllWheel-Drive system, adapted from the RL, is standard on the MDX and RDX. Torque going to the rear wheels is distributed side-to-side according to demand. However, if the vehicle is in a turn, it speeds up the outside wheel to help pull the car through the turn, rather than apply the inside wheel brake.