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View Full Version : Attn. 2WD/FWD Pilot Owners: valve noise in "eco" mode?


HondaDIY
03-02-2010, 07:01 AM
Greetings ALL!

We have a 2006 Pilot 2WD - the one with the three cylinder "eco" mode - with 64k+ overwhelmingly highway miles and searching the web for some clues as to what I've started experiencing over the last 1500 miles or so.

A little obsessive - I think I've tracked every gas tank's mpg since new - the Pilot settled in to a solid 23-24.5 mpg for tens of thousands of hi-speed highway miles, consistent regardless of temperature/time of year. About 5 weeks ago I noticed the mileage beginning to slowly drop, with my last trip this past weekend being slightly more than 21 mpg.

Looking back, I noticed that sometime during these past weeks I became aware of a very soft, subtle yet audible sound that I can best describe as the valves rattling or knocking - as if I had low octane gas in some older, pre-ECM vehicle - whenever eco-mode is engaged, i.e. 30 mph or more, and disappears if I bring in more gas to engage all 6 cylinders with a push on the pedal. I lose this sound as I approach external wind resistance noise around 60+ mph in eco-mode.

Anyone have similar symptoms?

Thanks in advance.

Rusty_212
03-02-2010, 09:51 AM
When were the valves adjusted?

HondaDIY
03-07-2010, 09:06 AM
When were the valves adjusted?

Thank you for the query, Rusty_212.

A member on the honda-tech.com board was able to come with some information here:

http://www.ht-archive.com/showthread.php?p=41792626#post41792626

I found a 5 page Honda service bulletin from late 2007 entitled "2009-11-30_204854_misfire_tsb.pdf" that someone uploaded to the web that details the problem, diagnosis, parts and repair procedure.

SYMPTOM
When the engine goes into VCM mode, it makes a
loud tapping or rapping noise. In addition, the MIL may
come on with DTC P0301, P0302, P0303, P0304,
P0305, or P0306 (No. 1 thru No. 6 cylinder misfire
detected).
PROBABLE CAUSE
One or more of the rear bank VCM rocker arm pins are
sticking.
CORRECTIVE ACTION
Replace the intake and exhaust rocker arms and all
related parts listed in this service bulletin.

Looks like an early morning visit to the closest dealer tomorrow.