So I've had this issue for a while now and it has just about everyone I know stumped. Sorry, this may be long several things have happened with the car since the code.
So the car is a 2005 Honda Civic EX with 5spd transmission. D17A2 motor with 241k miles.
The issue began shortly before my head gasket blew about a year and a half ago. The car will allow me to go past 4k in 1st and 2nd gear the first few minutes of driving, but then the rest of the time it will not go past it again, until the next startup. A code appeared - P2646 - which says "A Rocker Arm Actuator System Performance/ Stuck Off Bank 1".
After it appeared the car was taken into the shop where me and my boyfriend tore down the top end and sent the head off for resurfacing. It was a while before the car was back on the road as we had to wait for the head to come back and I had to buy some other parts to install as well.
Soon we got her back together and the problem was still there. We then started looking into possible causes and going through parts (and my bank account😭). We started with the oil pressure switch on the block. I bought one from Oreilly's and it was an Import Direct brand. When put in my gauge began flickering when my car was idling but it would stop when given gas. This was not the issue with the OEM switch. My boyfriend then took it out and we realized on the new one the hole on the motor end of the switch is smaller than that of the OEM - so we assumed this to be the issue and installed the old one back in.
I had also read that the oil could be low and the filter could be the issue but she had a fresh oil change after the head gasket replacement with ( I believe ) a Wix or Honda filter. So I ignored this possible solution.
Then we got to the "expensiveish" side of things. But I took the cheap route. I ordered a VTec solenoid from EBay and we installed it AFTER we tried cleaning the screen on my original solenoid didn't fix the problem. The new solenoid also did nothing. We took both and my boyfriend wired them up off the car to see if they worked on their own and they did. I also bought an oil pressure switch for the solenoid and that did not work either.
Currently, I am back to believing that the oil may be the issue. Not so much that it's low but maybe the quality of the brand I had been using. I always carry fluids (oil, antifreeze, water, brake fluid, washer fluid) in all my vehicles. So I noticed one day that a quart of oil I kept in my Honda had turned over in the seat and spilled into a clear, clean lid that went on a lil tool set i have in the car and the oil was filled with sandy, gritty stuff and I had just bought it the week before. It was store-brand oil.
I'm thinking of doing another oil change on the car. It's also time for it because she sat for months, because I kept getting faulty clutch hydraulic parts from the stores in my town. (4 clutch master cylinders, 2 slave cylinders, and one clutch line later she moves). I bought some Castrol full synthetic oil and a WIX filter. My boyfriend also agreed to try a oil pressure test before and after the oil change.
I'm really at the end of my rope because I don't want it to be an oil pump issue after having the car taken apart as long as I have for the head gasket and everything else.
Also worried it could be ECM because when I bought the car it had 1st O2 sensor code and after splicing in a new one (store wanted 300+ for correct one just because the harness was longer on it they were also special-order only) it still shows code but when hooked to computer the sensor reads correctly.
Have no clue what else to check out at this point. I'm honestly afraid I will damage this motor continuing to drive it as it is my daily.
Any ideas or avenues I may have missed??
So the car is a 2005 Honda Civic EX with 5spd transmission. D17A2 motor with 241k miles.
The issue began shortly before my head gasket blew about a year and a half ago. The car will allow me to go past 4k in 1st and 2nd gear the first few minutes of driving, but then the rest of the time it will not go past it again, until the next startup. A code appeared - P2646 - which says "A Rocker Arm Actuator System Performance/ Stuck Off Bank 1".
After it appeared the car was taken into the shop where me and my boyfriend tore down the top end and sent the head off for resurfacing. It was a while before the car was back on the road as we had to wait for the head to come back and I had to buy some other parts to install as well.
Soon we got her back together and the problem was still there. We then started looking into possible causes and going through parts (and my bank account😭). We started with the oil pressure switch on the block. I bought one from Oreilly's and it was an Import Direct brand. When put in my gauge began flickering when my car was idling but it would stop when given gas. This was not the issue with the OEM switch. My boyfriend then took it out and we realized on the new one the hole on the motor end of the switch is smaller than that of the OEM - so we assumed this to be the issue and installed the old one back in.
I had also read that the oil could be low and the filter could be the issue but she had a fresh oil change after the head gasket replacement with ( I believe ) a Wix or Honda filter. So I ignored this possible solution.
Then we got to the "expensiveish" side of things. But I took the cheap route. I ordered a VTec solenoid from EBay and we installed it AFTER we tried cleaning the screen on my original solenoid didn't fix the problem. The new solenoid also did nothing. We took both and my boyfriend wired them up off the car to see if they worked on their own and they did. I also bought an oil pressure switch for the solenoid and that did not work either.
Currently, I am back to believing that the oil may be the issue. Not so much that it's low but maybe the quality of the brand I had been using. I always carry fluids (oil, antifreeze, water, brake fluid, washer fluid) in all my vehicles. So I noticed one day that a quart of oil I kept in my Honda had turned over in the seat and spilled into a clear, clean lid that went on a lil tool set i have in the car and the oil was filled with sandy, gritty stuff and I had just bought it the week before. It was store-brand oil.
I'm thinking of doing another oil change on the car. It's also time for it because she sat for months, because I kept getting faulty clutch hydraulic parts from the stores in my town. (4 clutch master cylinders, 2 slave cylinders, and one clutch line later she moves). I bought some Castrol full synthetic oil and a WIX filter. My boyfriend also agreed to try a oil pressure test before and after the oil change.
I'm really at the end of my rope because I don't want it to be an oil pump issue after having the car taken apart as long as I have for the head gasket and everything else.
Also worried it could be ECM because when I bought the car it had 1st O2 sensor code and after splicing in a new one (store wanted 300+ for correct one just because the harness was longer on it they were also special-order only) it still shows code but when hooked to computer the sensor reads correctly.
Have no clue what else to check out at this point. I'm honestly afraid I will damage this motor continuing to drive it as it is my daily.
Any ideas or avenues I may have missed??