Engine had a rough idle, Check Engine Light intermittent, then always on as it got colder, scanner reads Misfire codes for cylinders 1,2 and 3.
The scanner crank angle readings. Negative rad/s for cyl 1,2,3, but +12 to 17 rad/s for cyl 4,5,6. This is where I suspected cam timing issues.
Checked compression showed 140lbs in each cylinder. O2 sensors bank 1, +0.89, bank 2, +1.0.
Timing belt listed as being changed 15 Jun 2017 at 106,000 miles. Vehicle now at 162,000.
Ran through Nail Grease checklist except for MAF cleaner spray. New plugs (Ruthenium), air filter, new upper O2 sensors, new PCV and EGR valve, swapped coils front to back. Tested for air leaks with carb spray.
Placed engine at TDC with upper timing covers removed and found rear cam one tooth retarded. The cam timing mark lines up with the black mark to the left of the timing mark on the head. The white mark on the back of the belt is one tooth forward.
Started a timing belt replacement.
This plastic fell out of the lower cover upon removal. It appears to be part of the plastic lip from the lower timing cover that slots into the upper cover. Looks like it went through the timing belt and sprockets from the indentations on both sides. This may
have caused the belt to skip a tooth on the rear cam and cause the misfire codes.
It’s a shame this happened. The parts removed are AISIN and all are in good shape. Anyone want these used parts?
I was expecting a failed tensioner, loose idler bolt, or cheap belt that allowed the belt to slip.
Installed the new AISIN kit with the cams properly located and this resolved the misfire codes and smoothed out the idle. Scanner showed smooth positive RAD/s across the cylinders.
My timing belt replacement experience.
Total time was eight hours. (AISIN instruction sheet states 2.5hrs to replace - ha!) I spent time cleaning the Engine Mount bolts with a wire wheel. The small bolt on the side of the chassis was stripped and I cleaned up the threads with a hack saw blade. I didn’t have a tap that size. I used anti-seize on those bolts. I replaced the engine mount with a new OEM one. I had to use a low profile 17mm socket and wobble on the engine mount small bolt and the one to the rear of the vehicle or I would have had to remove the computer. Previous access issues probably ended up with the small bolt getting stripped.
Power Steering pump. I did not disconnect any power steering hoses. I could not lift the pump onto the intake manifold, but I worked around it while it sat loose above the engine mounting area.
Coolant drain. Used the valve on the back of the block “around the corner” from the oil filter. I put a hose on it to drain into a bucket. When removing the water pump, very little coolant spilled out. Not even a shot glass worth.
Rear Cam. It did suddenly jump backward or forward and I had to hold it steady with a breaker bar while installing the belt. I also had to use the technique of rotating the cam slightly forward, not even a whole tooth, to get the belt onto the cam.
Caution. I now know why its called a “breaker bar”. With the breaker bar on the cam nut, the cam sprung forward and the breaker bar struck the Bypass Valve Assembly Actuator smashing it right off the intake manifold. I had to buy a new one to replace it. Luckily it didn’t break the gear inside the manifold.
Tensioner pully. As others have reported, I could not get the belt over the rear cam even with the tensioner pully bolt really loose and the tensioner pully hanging very loosely. I removed the tensioner pulley assembly altogether and the belt went on. It was easy to mount the tensioner pully back in place under the belt.
Cost: AISIN Kit $195, Bauer Impact $89, Lisle 19mm Heavy Impact socket $30, EOM Engine mount $52 shipped, Coolant 21, Coolant funnel kit $21. = $408.
Local Indy Honda shop estimate was $1,070 with mount, but timing kit was GATES at $279. Stealer? Didn't even ask.
DIY Saving $662. There is a lot of satisfaction doing it yourself and seeing it work out. It’s not difficult, just time consuming and fiddly accesses.