How to Change EGR Valves on Volvo D12 Diesel Engineby Contributor
If you own a Volvo D12 diesel engine you probably already know the EGR valves are the first thing to go. Let me show you the symptoms for bad valves and the procedure for changing them.
First the symptoms, If you notice a sudden loss of power especially on inclines, excessive smoke from exhaust stack and possibly a check engine light your EGR valves probably just bit the dust. If you change the fuel filters and inspect the turbo and the problem still exist I'm almost sure its your valves.
To replace, first drain the coolant from system and disconnect the battery cables. The valves are located on the right side of engine attached to the exhaust manifold just above the turbo, there are two of them. Remove the air filter housing, intermediate pipe and splash shield for access to valves. Disconnect coolant lines from valves and loosen clamps attaching tubes to valves and valves to manifold. Remove heat shield and follow valve wires to the left side of engine where they plug in behind the alternator. Remove the alternator and unplug the wires. Carefully lift out the valves and wires.
Install the new valves one at a time with the valve closest to the front of the engine being number 1 and the one in the rear number 2. Clamp valves onto manifold and tighten then reattach coolant lines and heat shield. Install new tubes onto valves. Route valve wires across the front of engine to plugs on left side of engine and plug in. Refill coolant to proper level in reservoir. start engine and let coolant temp build to about 150 degrees, if you hear no exhaust leaks the job is done, go ahead and reinstall air filter housing and splash shield and take for a test run.
- If not sure of failed EGR valves, consult a qualified diesel mechanic or tech for further diagnosis and troubleshooting.