My serpentine belt keeps wearing within a few weeks. Also I have a substance leak, either oil or antifreeze, or both. Any ideas where to start?

The P0420 code in a Honda Accord will often be thrown one of your oxygen sensors are not functioning properly. Typically, the code will be triggered by the upstream oxygen sensor (before the converter).


This link might help: https://www.google.com/search?q=p0420+and+p0011+code+for+2008+honda+accord&hl=en-US&biw=1366&bih=625&ei=128RYczCJprfz7sPyYuk2AY&oq=p0420+and+p0011+code+for+2008+honda+accord&gs_lcp=Cgdnd3Mtd2l6EAM6BwgAEEcQsANKBAhBGABQndwDWP68BGDrwQRoAXACeACAAW6IAagJkgEEMTAuM5gBAKABAcgBCMABAQ&sclient=gws-wiz&ved=0ahUKEwiMitCGxaTyAhWa73MBHckFCWsQ4dUDCA4&uact=5


What the P0011 code means. P0011 is the OBD-II generic code indicating the engine control module (ECM) has determined that the bank 1 intake camshaft is more advanced than what the ECM has commanded it be. This over-advanced condition could be during advancing or retarding of the camshaft timing.


This link might help: https://www.google.com/search?q=+p0011+code+for+2008+honda+accord&hl=en-US&biw=1366&bih=625&ei=InARYdyvH4LC3LUP6NiBgAw&oq=+p0011+code+for+2008+honda+accord&gs_lcp=Cgdnd3Mtd2l6EANKBAhBGABQ75EFWO-RBWCXowVoAHACeACAAXuIAd8BkgEDMC4ymAEAoAEBwAEB&sclient=gws-wiz&ved=0ahUKEwjcyKqqxaTyAhUCIbcAHWhsAMAQ4dUDCA4&uact=5

Remove the serpentine belt and check the pulley from water pump alternator air condition

Sounds like the power steering pump has failed.
You could take the serpentine belt off and check the pump pulley.

If the lower (intake) manifold is leaking, which is very common, then you should either have an external antifreeze leak, or antifreeze into the oil. Oil will not go into the antifreeze. The coolant used in this car (DexCool) does, however, form an oily substance on the surface over time. I would recommend having the antifreeze flushed out, and the reservoir cleaned.

intake gasket might cause it if the coolant froze and broke the seal between the head and intake and is leaking directly into the lifter valley

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Click the link below: ----

http://carbeltrouting.blogspot.in/2012/02/timing-beltdrive-beltserpentine.html
----------This will help. Thanks.

Check the oil fill cap to see if there is any water or antifreeze leaking into the oil through a bad gasket in the engine. To much water getting into the oil will ultimately cause your engine to seize, ruining your engine. A light tan substance on the underside of the oil fill cap also is indicative of water getting into your oil.

lack of service probably the cause try thicker oil or stp engine wear oil has it been stood for a while? if so recomend new oil and filter make sre you flush old oil out with cheap oil then proceed with oil change you can use oil flush too the oil should be golden once started after a week check oil again for signs of emulsification on the cap

Most likely a leaky gasket. The water pump is a likely candidate, but also could be from a bad radiator hose/thermostat connection. Would suggest washing down the engine with a hose connected to the hot water. While the engine is cold use the hose to wash off the oil & grease deposits and old antifreeze. Allow the engine to dry without running the car. Once dry start the car and be prepared to look for the first sign of a leak. Sounds like a dealer issue since there is very little work clearence between the front of the engine and the car body. Barely enough room to be able to change the serpentine belt.

You may have a lower intake manifold gasket leak (or a head gasket leak-slightly less probable) the lower intake can leak onto the serpentine belt and fling oil (and/or antifreeze). The lower intake manifold gasket is usually the culprit here. There is much information about changing it if you are inclined to do it yourself. If not, expect around 800 to 1200 to fix at dealer/mechanic. This is usually accompanied by (but not always) oil in the antifreeze, or antifreeze in the oil...