My name is Craig Nelson and I've owned my Pilot for 5 years. I bought it at 53,000 miles and now have 140,200 miles.

I want to directly consult with a senior Honda dealer technician or service manager by phone or e-mail to compare answers to what I have found as well as 2 Honda dealers and 2 independent shops. I have questions that may go beyond the dealership level, but need someone at a dealer with inside access to Honda of America to address my questions.

At 100,000 miles, the J35A4 engine developed a singular deep knocking sound at half engine RPM speed. It is the loudest when the engine and air temp is cold. When the engine is warm and the air temp is warmer, the noise is there but quieter. It's been slowly getting worse and am now getting more concerned about potential engine failure. Until then, I plan to drive the engine normally until something happens, which hopefully is not at the least opportune time.

Based on my stethoscope sessions and from one dealer diagnosis, I am 90% certain it is somewhere in the shortblock such as piston slap, wrist pin, or rod knock. It is isolated to the #5 cylinder in the front bank. The engine runs perfectly otherwise except for fuel economy consistently at about 15 city and 17-18 highway. Since I owned it, I've never had check engine lights, stored codes, and its never overheated. I've done all timing belt and other maintenance using genuine Honda parts. My only deviation from the factory maintenance is using a K&N drop in replacement air filter, and Royal Purple 5W-20 synthetic oil. I do use a Spoon Sports oil drain plug with the longer magnetic stem. I always wipe away gray ferrous sludge (ferrous dust). This could mean the bearing babbiting material has worn off meaning the crank and rod journals are now directly riding on the steel bearing shells. This would also support the rod knock theory.

My credentials:

I retired from the US Navy 3 years ago and have plenty of shadetree private automotive experience (1995 Civic EJ1 coupe in the October 2009 issue of Honda Tuning magazine), but no formal field experience. Since I left the Navy, I sold cars at a Kia dealership, I earned the associates degree from Wyotech, and am now earning a bachelors degree in Automotive Restoration from McPherson College in McPherson Kansas. I will graduate in May 2015.

Thanks!!!

 

Craig, I own a 2006 Honda Pilot and a 2008 Honda Ridgeline. The information I have is that the K&N drop in will not filter as well as the OEM paper. Take that for what it's worth. Otherwise, I can't see that your use of RP or that oil drain plug could have any possible effect on your engine health, as long as the oil meets the Honda spec.

Have you checked your spark plugs yet? The J35 is somewhat notorious for developing loose plugs and melting the coil pack and plug itself, with oftentimes catastrophic results for the engine. (you can search the issue over at Piloteers or the Ridgelineownersclub).

Regarding overheating, the temp gauge is buffered... ergo, I've seen 50*F temp swings and the gauge has never budged from its "normal" position. (~160*F-212*F). I have an OBD2 device which provides info from the OBD2 data stream to get that info.

I honestly don't know what temp it would take for the gauge to indicate an overtemp scenario.

Side note: one thing I would advise you to do is check your radiator/tranny fittings for excessive corrosion where the Belleville washer attaches to the radiator (two places near the bottom of the radiator). That's a known point of failure which results in the SMOD (strawberry milkshake of death) when tranny fluid and coolant mix... to the detriment of the tranny. This has been found on Pilots, Ridgelines, early MDXs, and other brands besides Honda. You can also search this issue on the above referenced sites.

My credentials? Wanna-be shade-tree mechanic. Sorry, I don't quite meet your requested expertise level, but I hope you find the info helpful.

 

pull the top intake runner and pull your valve cover and check the conditions of your cam loves , if there is some scratches replace cams , almost a $850JOB ,

 

How would scratched camshaft lobes cause my noise problem? Are we talking little or big scratches? Camshafts list for $290 each and can get them for $203 each. I can do the job myself. However shop labor should be $600 to $800 depending on dealer or shop rates, then the cost of parts for $400-$500. I don't know where your $850 number comes from.

My noise sounds very deep and hollow and it is coming from the bottom end, not from anywhere in the cylinder heads.

 

I've personally seen a few hydro timing belt tensioners fail causing the belt to slap the timing covers causing a noise similar to your description. Can you upload an audio file?

 

I don't have an audio file. However, the noise is most prevalent from the front of the engine block at #5 cylinder. It is not coming from the area of the hydro tensioner.

I changed the timing belt at 94,000 miles using brand new OEM Honda parts including the hydro tensioner, pulleys, the belt, and water pump. The noise was present before and after the timing belt change. Although it was a bit quieter then versus now.