Accord 2.4 Vtec
Ellyn Krucke
I have a 94 Honda accord Ex (F22B1). When I bought it a few days ago the previous owner mentioned a few of the issues that he could remember. Since I've only ever owned Honda's and have worked on them for some time I figured there wasn't a problem I couldn't fix. This one has me a little perplexed. I started it up and noticed that valve ?tapets? (sorry don't know what they are really called) were all loose and making noise. That night after the engine had a good chance to cool down I took the valve cover off and used my old trick of a 1/4 turn loosen on all the valves from full tightness. (Side note: This wasn't a blind un-thought out process. if you want to know more we can chat about it)
Put it all back together and it went from a full on clickity clakity motor to much quieter engine. However one of the valves is still making noise. I figured that because I did it sorta late and in a hurry that I didn't do as good of a job as I should have. So after driving it 120 miles the past few days and a much needed oil change I figured it was a good enough time to let the valves settle to their new clearance and decided to tighten them up again today but this time take more time doing it. Get it back together and one of them is still making noise. I'm fairly certain it is the #1 cyclinder's valves but I am still kinda guessing on that. Anywho I've just never had that happen to me before where it was still making noise after adjusting all of the valves. Any suggestions?
Last question: How do I know it's not the rod bearings? I used to think it was speed between clicking noises, but when I put my head in different areas of the engine bay it sounds like it's coming from the front of the engine and gets louder when I put my head closer to the exhaust manifold instead of next to the valve cover.
Set the valve clearance with feeler gauges. Exhaust .012" Intake .010". 30 yrs of Honda and I still do not trust any other method. If one of my employees does not use gauges we will be having a chat...
Possible causes of valve train tick. Worn camshaft lobe. Sticking valve. Sticking rocker arm bearing. Loose timing belt sprocket bolt. Worn cam bearings.If this has the V-tec system then that opens up other possibilities.
The Accord is available in two bodystyles: a sporty Coupe and an elegant four-door Sedan. Five different trim levels are available: DX (Sedan only), LX, EX, V-6 LX and V-6 EX. Both the Coupe and Sedan bodies are completely new, with distinctive styling that distinguishes each from the other. Each body provides even greater structural rigidity, and has been designed to meet current U.S. safety standards for occupant protection. In addition to front-, rear- and side-impact protection, the new body features extensive offset-frontal impact protection. Lap/Shoulder seat belts are used at all seating positions, including the middle-rear position, and dual airbags are standard.
3.0-LITER, V-6 ENGINE
A 200-horsepower, aluminum-alloy, 3.0-liter, V-6 engine is available in LX and EX sedans and coupes. Its 60-degree V angle and extensive noise and vibration engineering make it exceptionally smooth. In addition, the V-6 is quiet and the most compact and powerful V-6 in its class.
2.3-LITER ENGINE
A 2.3-liter, aluminum-alloy, in-line 4-cylinder engine with a VTEC cylinder head is standard on the Accord LX and EX models. (DX models retain the non-VTEC 16-valve head.) This is the first time VTEC has been used on LX models.
The 2.3-liter engine is a complete redesign and boasts more power, less vibration and better fuel efficiency than its predecessor. In addition, the VTEC LX and EX versions meet California's LEV (Low-Emission Vehicle) standards.
5-LINK DOUBLE WISHBONE REAR SUSPENSION
The Accord's chassis gives it an exceptionally smooth ride and precise, stable handling. The chassis features a 5-link double wishbone rear suspension and a redesigned double wishbone front suspension, combined with innovative front and rear subfrarnes that yield a high degree of isolation from vibration.
Three engines are available for the Accord: There is 3.0-liter, 200-horsepower, 24-valve V-6 and two 2.3-liter 4-cylinder engines. A 5-speed manual transmission is standard on 4-cylinder models and a 4-speed automatic transmission is available for the 4-cylinder engines and standard on V-6 models.
The 3.0-liter, 200-horsepower, 24-valve V-6 is the first V-6 engine to use VTEC (Honda Variable valve Timing and valve Lift Electronic Control system), Honda's variable valve timing system. VTEC helps give the V-6 a broader, more powerful torque curve. All engines and transmissions are built at Honda facilities in Ohio.
The Accord's 2.3-liter, in-line 4-cylinder engine is shared by DX, LX and EX models and features a 16-valve cylinder head and a vibration-canceling second-order balance system. Both LX and EX engines receive California Low-Emission Vehicle (LEV) certification, thanks in part to the application of VTEC technology.
Accord V-6 sedans and coupes are powered by an aluminum-alloy, transversely mounted, 3.0-liter, 200-hp V-6 engine. The engine features 4 valves per cylinder (24 total), single overhead camshafts and VTEC.
The V-6 is quite compact and incorporates several innovative features that help minimize its size, weight, friction and vibration. The block is heat-treated, die-cast aluminum and is very compact and rigid, with a high natural frequency and minimal resonant vibration. In addition, its 60-degree V angle serves to minimize vibration. Bore and stroke are "square," each measuring 86 mm, for a total displacement of 2997 cc. The cylinder liners are cast-iron.
The V-6's narrow 98-mm bore spacing contributes to the engine's short over-all dimensions. The block-deck height (and piston compression height) is minimized by the use of ultra-short skirt pistons. The com-pression ratio is 9.4:1 and regular unleaded fuel is specified.
The pistons are 51.5 mm tall and use ultra-short skirts. In addition, the skirts are thicker and more rigid than those used on the previous engine, which helps to further minimize vibration and friction.The piston pins are a full-floating design whose small clearances result in less noise, especially during engine warm-up.
The pursuit of a lightweight, compact design mandated special care in crank-shaft and connecting-rod engineering. The engine's connecting rods don't use conventional nut-and-bolt type fasteners, but instead employ lighter bolts (without nuts) called plastic-region fasteners. These bolts are designed to operate in the plastic, not elastic, region of the steel material, unlike conventional fasteners. This allows downsized rod bolts to maintain relatively greater clamping force and handle operating stresses with normal strength margins. It also uses a special dual-mode crankshaft damper pulley. Overall engine width is 485.5 mm (as transversely installed in the car). That makes the power-plant narrower than the 3.0-liter V-6s in the Toyota Camry or Nissan Maxima.
Pressure-cast of aluminum alloy, the Accord's cylinder heads echo efforts visible throughout the engine to minimize weight and size. In the interest of simplicity, the single overhead cams are installed in the heads from the end, instead of being clamped in place from above with bolt-down caps.
The 4-valve-per-cylinder design offers several advantages over 2-valve arrangements, most notably the reduced reciprocating mass, which allows the engine to safely reach higher rpm and develop greater horsepower. Additionally, valve area is increased with the use of four valves, relative to conventional 2-valve systems, resulting in improved air flow. Remarkably, the Accord V-6 has comparable or better horsepower, and competitive fuel economy with other engines in its class, and meets California's strict standards -- all while burning regular unleaded fuel.
The Accord V-6's valves are actuated by roller followers and a single camshaft per cylinder bank. The U.S.-sourced camshafts are constructed of ductile iron, flame-hardened, then quenched to achieve the necessary hardness. The cams are turned by a glass-fiber reinforced, toothed belt, which is driven by the camshaft. An automatic tensioner compensates for belt-stress fluctuation.
The Accord V-6 engine uses Honda-programmed, sequential fuel injection. Air induction is via a cast-aluminum intake manifold with individual, tuned-intake runners. A tuned plenum and throttle body connect to the upper end of the manifold.
Emissions of Non-Methane Organic Gases (NMOG), also known as unburned hydrocarbons, produced during engine warm-up are considerably lower. The LX and EX engines produce less than 0.0075 grams per mile, qualifying them for California LEV (Low-Emission Vehicle) status. In California, the Accord EX with the available automatic transmission will produce less than 0.003 grams per mile of NMOG, qualifying it as the first gasoline-powered vehicle to reach ULEV (Ultra-Low Emission Vehicle) status.
The five-main bearing block is high-pressure die-cast from aluminum alloy. The walls of the block extend below the centerline of the crankshaft, which helps stiffen the bottom end. FEM (Finite Element Method) computer analysis was used to arrive at optimum thicknesses for the block ribs and walls in order to minimize engine vibration.
An aluminum-alloy stiffener has been added between the transmission case and the block, just behind the bearing carrier. The stiffener serves to tie the block and transmission together into a single, reinforced unit. FEM was also used to design this stiffener so that it would not only stiffen the area, but also help minimize high-frequency engine vibration.
Finite-element analysis of the Accord's piston design by Honda engineers yielded a new ultra-short, lightweight skirt design, which is very rigid and resistant to vibration and piston slap. Like the V-6 engine the pistons are gravity-cast aluminum alloy and utilize full-floating wrist pins in order to minimize noise.
The I-section, drop-forged steel connecting rods have a completely new design and are considerably lighter than their predecessors (475 g vs. 578 g), which helps to minimize vibration. Pin-journal (big end-bearing journal) diameter has been reduced from 48 mm to 45 mm. Rod thickness is down from 24 mm to 20 mm and the bolt size is smaller. Like the V-6 rod bolts, those of the 4-cylinder engine are torqued to the plastic region of the bolt material in order to ensure a solid union between the bearing cap and the connecting rod.
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