The cylinder layout in the engines of VW cars produced between 1992 and 2010 was the row-shifted or VR-type. In these engines, the cylinders are mounted in the same block, but not in a row, but at an angle of 15º relative to each other’s center. The intake passages are on the left and the exhaust passages on the right. This makes VR engines similar to single-row motors. VW engines were equipped with 5 or 6 cylinders with a working volume of 2.3-3.6 liters.
Technical specifications
| Characteristics | Value |
|---|---|
| Exact volume | 2324 cm³ |
| Power system | Injector |
| Engine power | 150 hp |
| Torque | 205 Nm |
| Cylinder block | Cast-iron VR5 |
| Cylinder head | Aluminum 10v |
| Cylinder diameter | 81 mm |
| Piston stroke | 90.2 mm |
| Compression ratio | 10.1 |
| Engine Features | No |
| Hydrocompensators | Yes |
| Transmission timing | Chain |
| Fasor regulator | No |
| Turbocharger | No |
| Oil | 4.0 liter 5W-30 |
| Environmental class | Euro 2/3 |
| Example service life | 275,000 km |
This time we evaluate the VR5 2.3 engine with the index AGZ. This engine is one of the simplest in the VR range from VW. Under the cast iron block cover there are 5 cylinders with 2 valves on each, controlled by two camshafts of different sizes. At the rear of the engine is a dual chain timing drive. VR5 2.3 engines used variable geometry intake manifold. The VR5 10-valve engine was installed in 1997-2001 on the following Volkswagen models:
- Bora;
- Golf;
- Passat.
Seat Toledo cars were also equipped with the same engine. The successor of the 10-valve VR5 was a 20-valve engine. The working volume has not changed.
Resource of VR5 2.3 engine
VR5 is quite reliable and durable motor. The average resource of such an engine reaches 500,000 km and more. True, maintenance of VR5 is not cheap. Especially it concerns timing chains. Their replacement is also quite labor-intensive. The price for the dual-mass flywheel of this engine also bites. It is impossible to find such spare part cheaper than for 715$. However, with proper, timely maintenance and professional service, cars with VR5 engine do not cause any special problems to the owner.
Problems.
Oil leakage on the valve cover seal
Almost all VR5 engines eventually started leaking valve cover due to gasket wear. The gasket is not sold separately, only in a set with the original cover, (price 220$). Analogs for VR5 engines are not produced.
Idle idle problems
Unstable idling is a common disease of VR5 engines. The main cause of floating rpm is air leakage outside the flow sensor (flow meter). The easiest way to determine the location of depressurization is to use a smoke generator to pressurize the intake manifold. Air usually passes through the crankcase ventilation valve body, the intake manifold geometry change system or the throttle body seal.
Racing or high idle speeds also occur if the throttle plate is dirty or if the “flute” of the intake manifold geometry change mechanism is wedged.
Also, the engine can noticeably vibrate with failures in the ignition system.
VAC valve
Inside the valve of the VKG system, located next to the throttle valve, there is a diaphragm. Over time, it wears out and allows oil vapor to pass through, clogging the air flow sensor and air filter. The problem is corrected by completely replacing the crankcase ventilation valve (part number 3B0128101).
Leaks in the thermostat housing, coolant temperature sensor, and cooling pump
There is a cooling system flange with the thermostat inside (thermostat housing) on the rear end of the VR5 engine. On cars with significant mileage between this splitter and the motor there is a leak, the plastic of the housing is cracked. It is not easy to replace because of its location.
In addition to the thermostat in the splitter is installed and antifreeze temperature sensor. Not infrequently, when his case was covered with cracks. This is another of the causes of coolant leaks.
Antifreeze leakage can also be a consequence of damage to the housing of the cooling system pump, which works from the belt of the attachment. The pump has to be replaced completely.
For the circulation of antifreeze after the engine stops, an additional pump installed in the rear of the engine is responsible. It is driven by an electric motor. Failure of this pump can cause the coolant to boil in the cylinder head and, as a consequence, deformation of the head itself. Usually, after stopping the engine, the electric pump hums for a while. If the sound of its work is not heard, you can check the performance by applying 12 V to the pump contacts. If the part has failed, it will be necessary to install a new one.
The coil and switch ignition system
Ignition in VR5 engines with 10 valves is represented by a commutator and a coil module. The spark plugs are connected to the ignition coil by high voltage wiring.
As mileage increases, the ignition coil housing cracks and crumbles, and the contact stud may break. Because of this, in some cylinders the fuel is ignited late or not ignited at all. The problem is eliminated by replacing the module.
If after this ignition skipping is still observed, it makes sense to check the ignition switch by dialing contacts 2-6. If there is no response from one or more of them, the commutator is also necessarily changed.
Pistons and fuel system
The fuel injectors installed on the 10-valve VR5 engines are virtually trouble free. Owners of cars with high mileage in order to increase the power of the motor sometimes resort to cleaning the injectors. Indeed, the speed increases, but for the procedure it is necessary to use only special liquids used in the usual spillage.
Rarely, but it happens that one of the injectors fails, provoking a skip of ignition in one of the cylinders. A short circuit is observed in the problem injector when diagnosed.
Over time, the VR5 engine may not operate at full power under heavy loads. This may be due to a decrease in pressure in the fuel ramp. The normal value with a serviceable pump and regulator is ≥ 3 bar.
Timing Chains
Timing chains have a service life of approximately 250,000 km. When they are stretched, a distinctive rumbling noise is heard from the rear of the engine. When the upper chain is stretched, the chain breakers can crack. The rumble is then heard more clearly.
If the upper chain is significantly stretched, it can “skip” one tooth of the short camshaft. This usually happens if the car is in gear and at the same time rolls backwards a little.
Another cause of chain overshoot is when an inexperienced auto mechanic turns the crankshaft counterclockwise during service. The chain pushes the hydraulic tensioner back a little and slips when the engine is turned on.
Such a situation most often does not entail serious problems. But an error on the camshaft sensor pops up, the engine starts to malfunction, fuel consumption increases, and the exhaust clearly smells of gasoline. The problem is eliminated by rechecking the timing marks and correct adjustment of camshafts.
If the chains are stretched, the entire timing set may be replaced. For VR5 (AGZ) engines are produced analogs (about 250$). The price of the original is an order of magnitude higher. Changing chains after removing the gearbox, hanging the engine on the crosshead.
Oil
The VR5 engine has not been noticed in oil overspending, but after about 300 000 km of mileage it “goes away” about 200 g for every 1000 km. The reason is the wear of the valve seals. Their replacement helps to return oil consumption to normal.
To prevent oil vaporization in the intake tract, it is necessary to periodically check the “fungus” (VKG valve). As for the CPG, oil is consumed here only in case of serious wear of rings and liners due to untimely refilling.