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If it were a piston wrist pin, you would think disabling that cylinder from firing (unplug coil), which he tried, would have isolated it.
I once had a weird knock that turned out to be loose flywheel to torque converter bolts (obviously not an S). Point being it could be something else loose.
He said it sounds front of motor, yet not any of the serp belt stuff. Timing chain gear related?
Maybe pull valve cover again and make sure nothing related to cams or timing sprockets are loose.
Alright guys after a myriad of tests I'm leaning towards this being a possible cracked or worn piston wrist pin. I see what you were saying about taking the stress off of the faulty part but I would think the friction of the piston rings against the cylinder wall along with the speed of the crank and rod would still make a pretty audible knock. That being said before I go shell out $430 for just one piston, rod, and wrist pin, does anyone with a blown ap1 have any leftover useable piston/rod assemblies? The condition of the bearings and rings do not matter as long as the rod, wrist pin, and pistons have normal wear.
Also it's hard to know for certain but I'm attributing this wear/failure to a lack of oil in the head. Either from years of subpar flowing oil filters or maybe the recent past owner not putting the correct weight oil in. As most people tend to not follow the oil cap on their cars and just use generic 0w-20, 5w-20, or 5w-30 instead of the specified 10w-40 because the jiffy lube doesn't have 10w-40...
That was my original suspicion. I clearanced the valves 2 days ago before I started this tread. Intake at .08 to .10 in and exhaust at .10 to .12 in. Also new spark plugs torqued to 15 ft/lbs. The plugs in there looked to be the originals from 16 years ago.
Also here's my best pic of the oil filter
It looks to be a protune filter from auto parts international. The brand only sells to shops and not individuals, however I was unable to find anything else about the filter. A search of the filter number on returns the makers website and an Ebay ad. Speaking on that I'm almost 100% certain that this is just some generic filter for Hondas, or worse just a filter the fit the thread size and pitch of the oil filter mount. Going to replace asap with an OEM Honda blue filter provided that the local dealership has one in stock or alternatively I'll go with a k&n filter.
Just by looking at that filter I get scared. It looks whack. You should get the OEM filter specifically made for our cars. Its large, blue and has the part number PCX xxxx.
Alright guys after a myriad of tests I'm leaning towards this being a possible cracked or worn piston wrist pin. I see what you were saying about taking the stress off of the faulty part but I would think the friction of the piston rings against the cylinder wall along with the speed of the crank and rod would still make a pretty audible knock. That being said before I go shell out $430 for just one piston, rod, and wrist pin, does anyone with a blown ap1 have any leftover useable piston/rod assemblies? The condition of the bearings and rings do not matter as long as the rod, wrist pin, and pistons have normal wear.
Also it's hard to know for certain but I'm attributing this wear/failure to a lack of oil in the head. Either from years of subpar flowing oil filters or maybe the recent past owner not putting the correct weight oil in. As most people tend to not follow the oil cap on their cars and just use generic 0w-20, 5w-20, or 5w-30 instead of the specified 10w-40 because the jiffy lube doesn't have 10w-40...
10W40 is not specified for our cars Kurt. 10W30 and 5W40 are (see the manual) however 5W30 is perfectly fine too. You're right, the wrong weights, cheap ass oil, wrong filters, etc all could have contributed to the state your engine is in now. Sad but true...
Its crucial to shell out for high quality full synthetic oil from trusted brands (recommended by many of us here) in the forum in the appropriate weight/viscosity for the Honda S2000 to perform at its best and stay bulletproof forever.
Hello all. To revive this tread of mine with the solution, it turned out to be a loose center bolt on the timing chain/camshaft idler gear. It took the the teeth on my exhaust cam gear shearing off to realize it. While replacing the timing/cam idler combo pulley after removing the tct the bolt was less than finger tight. The entire combo gear could be moved 3/4 in front and back. This part is just speculation but it may have been done when the previous owner installed Billman's tct and likely started to remove the wrong bolt but for got to re-torque it properly. As time went on and the knocking got louder he stopped making payments and gets his car (with a knocking motor) repossessed. Car gets bought by a used lot dealer from auction and enter Me. Even after this ordeal I still say 12.5k for an Ap1 03 MY with 65k miles was a steal. Now the motor runs like a sewing machine and hopefully I'm happy for years to come.
I would like to thank everyone who posted for their knowledge and advice. Truely a great forum to be apart of
I'll attach pictures of the damage below. (Sorry for the image size)
Sheared Teeth on Exhaust Cam Gear Scoring on Exhaust Cam #4 Cam cap Gear Teeth and Shards from Oil Pan
Last edited by Kurt Crafton II; 12-10-2019 at 09:40 AM.
Reason: Added Pictures
03-27-2019, 12:32 PM
