engine knocking at 2500+ rams
Please forgive me if I misname some parts. I am marginally knowledgeable about these things. I like to say I know just enough to be dangerous.
I purchased my 2009 Pilot LX, V6 3.5, used from a private party with ~65K. I take great pride in my vehicles and performing proper maintenance. I have the oil changed every 3K with a synthetic blend of 5W30. I used a very good and trusted local mechanic with many years of experience on all kinds of vehicles with engines, but mostly cars and trucks. He is the most trusted mechanic in the county.
I have owned it for two years. Recently, at about 85K I noticed a loud knocking noise when accelerating, starting at 2500+rpms. It mostly dissipates at 3000+rpms. The noise is extremely faint at idle and all other rpms.
My mechanic and I did some research and checked service bulletins. We discovered that this is a known issue, at least to some. There was a similar posting on a website called piloteers.org. In layman's terms, apparently the shafts the rocker arms pivot on were outsourced by Honda in 2009-2010 engines, and these tubes/shafts have developed too much slack and are shifting, causing misalignment between the rockers and cam.
My mechanic said that at this time this is only occurring on the "back" set of cylinders (1, 2, 3?). He followed service bulletin recommendations to remove and re-torque the rocker arm shafts, and adjusted the valves. Apparently this resolved the issue for some owners. Unfortunately, it has not for me.
Now, he is going to have to dig back into it. Replacing the rocker arm shafts may resolve it, but it is too difficult to determine if there has been damaging wear and tear on the camshaft and rockers, so we are replacing those as well. The repair also requires the removal of the timing belt, which isn't recommended for this vehicle until it reaches 105K. I am going to go ahead replace the timing belt now, however. I am frustrated to experience such a significant engine issue before I even have to replace the timing belt. To me, this is uncharacteristic of Honda's reputation for quality engineering.
Apparently Honda has not yet acknowledged it, accept responsibility, or offer mitigation for repair. When I call the local dealer they claimed not knowledge of this issue. I contacted Honda USA Customer Service. They, too, denied knowledge of this problem. It sounds like it may take a class-action lawsuit, much like their "Honda Engine Misfire Settlement" did. A judge in this case forced a warranty extension. See Honda Service Bulletin #13-082.
Once the repair is complete I will report back with additional details.
Update from Aug 2, 2016: The noise continued to worsen. My mechanic did some more digging around and now thinks the seals/bearings on the crankshaft are shot. He recommended replacing the engine, as he said replacing these requires a near complee engine dismantle, there is not guarantee the repair will hold, and for that kind of money and risk I am better off buying a good used junkyard engine or a re-manufactured engine.
engine knocking at 2500+ rams Please forgive me if I misname some parts. I am marginally knowledgeable about these things. I like to say I know just enough to be dangerous. I purchased my 2009 Pilot LX, V6 3.5, used from a private party with ~65K. I take great pride in my vehicles and performing proper maintenance. I have the oil changed every 3K with a synthetic blend of 5W30. I used a very good and trusted local mechanic with many years of experience on all kinds of vehicles with engines, but mostly cars and trucks. He is the most trusted mechanic in the county. I have owned it for two years. Recently, at about 85K I noticed a loud knocking noise when accelerating, starting at 2500+rpms. It mostly dissipates at 3000+rpms. The noise is extremely faint at idle and all other rpms. My mechanic and I did some research and checked service bulletins. We discovered that this is a known issue, at least to some. There was a similar posting on a website called piloteers.org. In layman's terms, apparently the shafts the rocker arms pivot on were outsourced by Honda in 2009-2010 engines, and these tubes/shafts have developed too much slack and are shifting, causing misalignment between the rockers and cam. My mechanic said that at this time this is only occurring on the "back" set of cylinders (1, 2, 3?). He followed service bulletin recommendations to remove and re-torque the rocker arm shafts, and adjusted the valves. Apparently this resolved the issue for some owners. Unfortunately, it has not for me. Now, he is going to have to dig back into it. Replacing the rocker arm shafts may resolve it, but it is too difficult to determine if there has been damaging wear and tear on the camshaft and rockers, so we are replacing those as well. The repair also requires the removal of the timing belt, which isn't recommended for this vehicle until it reaches 105K. I am going to go ahead replace the timing belt now, however. I am frustrated to experience such a significant engine issue before I even have to replace the timing belt. To me, this is uncharacteristic of Honda's reputation for quality engineering. Apparently Honda has not yet acknowledged it, accept responsibility, or offer mitigation for repair. When I call the local dealer they claimed not knowledge of this issue. I contacted Honda USA Customer Service. They, too, denied knowledge of this problem. It sounds like it may take a class-action lawsuit, much like their "Honda Engine Misfire Settlement" did. A judge in this case forced a warranty extension. See Honda Service Bulletin #13-082. Once the repair is complete I will report back with additional details.
Update from Aug 2, 2016: The noise continued to worsen. My mechanic did some more digging around and now thinks the seals/bearings on the crankshaft are shot. He recommended replacing the engine, as he said replacing these requires a near complee engine dismantle, there is not guarantee the repair will hold, and for that kind of money and risk I am better off buying a good used junkyard engine or a re-manufactured engine.
- jkw0376, Coralville, IA, US