nauticare94

First of all, thank you all for sharing your previous posts! I'd been going through them to get a game plan formed for my daughters Accord. It'd been misfiring randomly, and it would sometimes almost seem to go into limp home mode. A shut down - restart would cure that every time. It spit codes P0740, P1399 and P0300 through P0306. The P0300's were random though. Sometimes P0301, sometimes a different cylinder, sometimes 3 different cylinders. You get the gist of it. It was also shifting very hard going into any gear from Park, whether cold or hot, and wasn't the smoothest thing while driving either. With 231k on the clock I wasn't sure it was worth fixing... but it's a clean car otherwise with cold AC, and it's paid for. I finally had some time off work, she was out of town and left her car, so I went after it.

First up was checking valve train condition. While disassembling I discovered the previous owner had installed multiple brands and types of spark plugs. Only 2 were the proper NGK Platinum. The other 4 were mismatched non-platinum. It was like he grabbed whatever he had on hand at the time and stuck them in. Plug cavities 1 and 2 were full of oil, ironically that's where the 2 NGK's were located. Also, one of the small vacuum lines on the back of the intake was disconnected. After valve covers came off I discovered a VERY clean valve train, looked like brand new actually. With all these little things adding up that weren't quite right, I decided to dig in.

Valve lash check showed all were very close to perfect except an intake valve on cylinder #5. Slight adjustment needed there, maybe 3/4 of a turn. Replaced plugs with NGK Iridium and resealed both valve covers. I also checked the EGR passages on the intake manifold, they were clear. Double checked all vacuum lines and cleaned the throttle body.

Next up was the EGR valve. Removed it and cleaned thoroughly with throttle body cleaner. Much carbon came out, but no chunks or anything. Gasket and valve looked new otherwise, so I reused both.

It was time for the timing belt due to not knowing when it was last changed. Also, I was suspect of the crank sensor being a culprit. Upon disassembly I discovered the lower timing belt cover had a seal out of place which allowed for much road grime and gunk to build up on top of the crank sensor. The gunk was almost touching the timing belt. How it ever got a reading I'll never know. Cleaned the sensor and reused. The belt was holding on by a thread, and the water pump was also very worn. So glad I went after that job!

Transmission time. I drained the fluid and replaced the 3 quarts I'd removed. I ended up doing this again after 50 miles, and probably will again next month. The solenoid valve body on top of the tranny was pulled out so I could clean it. There are 4 transfer tubes in there as well, 3 of which have mesh filter screens. Mine were all plugged up. Sprayed them with throttle body cleaner and allowed to air dry, then reinstalled.

The first drive was frustrating at first. Ran and shifted like garbage. Throughout the drive it did get better. Lots better. Only went about 7 miles, but by the time I'd returned it seemed to run pretty smooth, and was it shifting better. It was like the computer was relearning the car, and the tranny was cleaning itself of gunk. Still threw a P0740 code, however. I put about 50 miles on it then dropped more tranny fluid out. After that it was like night and day. Silky smooth, lots of power, no hard shifting at any point. It's actually driving like a new car again!

After all the work I've driven 150 miles of mixed use over 3 days. I can confidently say it's fixed, aside from the P0740 for the transmission. I'm pretty sure the only fix for that is going to be a rebuild or replace, but I'll swap more fluid out in a little while just in case.

In the meantime, I'm considering it job done!

Thanks again to everyone else that posted ideas, tricks and tips! It was well worth the effort.