To understand the variable valve timing (VVT) solenoid and associated oil control valve (OCV), it’ll help to understand the history of this device and the way it benefits our cars, SUVs and lightweight trucks today.
The valves within the engine of your car, SUV or truck operate to regulate the flow of air, fuel and exhaust gases through the engine combustion chambers. These valves are pushed open and closed by camshafts.
There could also be as many as four camshafts counting on the engine type in your vehicle. These camshafts are typically chain or belt driven from the engine crankshaft.
The cams in vehicles of decades past provided a hard and fast pattern of valve operation with reference to the position of the pistons. This pattern (called valve timing) was pre-determined and designed into the engine by the manufacturer. Valve timing was set to to realize the simplest performance while yielding acceptable fuel economy.
Variable Cam Timing
Then variable cam timing (VCT) came along. this idea introduced cam timing that varied around a predetermined pattern of valve operation.
Patents for such systems on early engines date as far back because the 1920s. Engineers reasoned that varying the valve operation as engine speed changes could offer both performance and fuel economy benefits.
Alfa Romeo was the primary manufacturer to supply VCT on a production automobile. This feature came standard on the two .0L fuel injected engine within the 1980 Spider. the planning was very basic and provided valve retardation as engine speed increased.
The effect of this mechanism was to feature mid-range power. This one change greatly benefitted this small Alfa engine.
Gradually, variable cam timing began to catch on. Honda incorporated this in their VTEC engines in 1989. Porsche introduced it with the VarioCam within the V8-powered 928 model. Variable cam timing also began to ascertain wide acceptance in motorcycle engines within the early 2000s.
Borg Warner recently developed a VCT system for the 2016 Hyundai Lambda II engine series. this technique incorporated the primary use of a cam mid-position lock to carry the cams at a middle setting when no advance or retard was required.
Today virtually all automobile builders have jumped on board the VCT train. And beyond just performance and fuel economy benefits, VCT has been found to assist reduce vehicle emissions like oxides of nitrogen.
What is an Oil Control Valve (and How Does It Work?)
In latest automobiles engines, varying the valve timing is completed by cam control mechanisms that alter cam position with reference to the engine crankshaft.
These systems utilize the readily available oil be due the engine lubrication system to try to to the work. Here’s how that happens:
You are stopped at an intersection or simply cruising along and you tread on the gas. Signaled by the ECU (electronic control unit), the variable valve timing solenoid opens its integral oil control valve. When this valve opens, oil struggling flows to the cam control mechanism quickly changing cam position with reference to the driving chain or belt.
The cam position are often advanced or retarded counting on the engine speed and throttle (gas pedal) position. When the engine reaches a gentle speed, the OCV closes and therefore the cams return to their initial positions. This activity occurs almost instantly and is invisible to the driving force .
There is a secondary benefit to the present system. The OCV directs endless flow of oil to the timing chain and associated sprockets increasing lubrication and cooling oil flow to those parts.
Bad Oil Control Valve Symptoms
The VVT solenoid and OCV comprise an integrated unit. This unit can malfunction. When it does, any or all of those symptoms can provide you with a warning to problems:
#1 – Rough Idle
Under normal conditions, the VVT system activates at higher RPMs or when under load bearing conditions like driving up a hill. But with a faulty oil control valve or VVT solenoid, excess engine oil could also be introduced into the VVT system which may end in rough idling, stalling, or simply poor engine running generally .
#2 – Poor Acceleration
The engine will accelerate more slowly than normal. Power to accelerate quickly and/or climb hills are going to be lacking. While you’ll think this isn’t that big of a deal, there could also be times where you would like to floor it to stop an accident. When that power isn’t there, there’s not much you’ll do.
#3 – Poor mileage
As already mentioned, one among the advantages of variable valve timing is a rise in fuel economy. But when the oil control valve is faulty, that benefit disappears as intake and exhaust valves may open or close at the wrong times. Over a period of your time , you’ll note a rise in fuel consumption.
#4 – Check Engine Light
Invariably, the check engine light (CEL) will come on. A code are going to be set by the onboard diagnostic system (OBD2). This code will indicate whether the issues you’re noting are associated with the OCV and its related VVT solenoid. DTC P0014 is one such code associated with VVT.
As with all CEL ‘on’ events the car could also be driven for brief distances but must soon be seen by a service technician for corrective action.
What Causes the VVT Solenoid and OCV to travel Bad?
The VVT solenoid is electrically powered as signaled by the ECU. Any fault during this system or circuitry can cause the VVT solenoid to fail to work . Additionally the solenoid itself can have an indoor electrical malfunction and start to work intermittently or not in the least .
The OCV utilizes engine oil and requires clean oil to function normally. If oil and filter changes aren’t conducted periodically as your owner’s manual dictates, sludge and/or varnishes (sticky deposits) may build up during this valve.
This contamination may slow or block its function. Also, though this valve is comparatively simple, an indoor mechanical failure can cause it to fail to work .
Many OCV installations include an inline oil screen before the valve oil inlet. This screen can become partially or completely blocked by dirt or sludge. This blockage can hinder flow to the OCV and will cause it to fail to work .
Again, clean oil is vital . Periodic engine oil and filter changes can help preclude this sort of failure.
Can You Drive With a Faulty Oil Control Valve?
You can drive with this valve malfunctioning, but you shouldn’t drive too far. going to your neighborhood fix-it shop or dealer as soon as possible is strongly recommended.
The reason why is that the OCV or oil screen could also be partially or completely blocked. If this happens, lubrication to the cam sprockets and chains will slow or cease. this will cause rapid cam sprocket and chain wear then failure.
The resulting damage might be quite costly to repair.
VVT Solenoid Replacement Cost
VVT solenoid replacement will involve possibly a diagnostic fee, then labor and therefore the cost of the parts as follows:
If your mechanic charges a diagnostic fee, it could range from $65 to $100. Average parts cost will likely be somewhere between $50 and $250. Labor for the VVT replacement could range from $75 to $200.
All together, you’ll expect to pay somewhere within the range of $210 to $550 for the whole job.
Evidence of contamination and sludge within the oil control valve or filter could require additional work. this is able to contains flushing the engine lubrication system and replacing the engine oil and filter. Additional estimated cost for this work plus oil and a filter would be $125.