Replacing VTEC Spool Valve Assembly Filter on the 2003 Accord

The featured image says it all. My VTEC spool valve assembly was leaking oil and I figured to change this. This procedure explains how to change the spool valve assembly filter (PN:15810-RAA-A02). This will also double for the replacement of the VTEC spool valve assembly. The oil was leaking onto my oil filter giving the impression that there was a problem from there.

Leak form VTEC Spool Valve Assembly

Wetness on the VTEC Spool Valve Assembly

Materials: 10mm wrench and replacement spool valve filter.


New OEM VTEC spool valve filter

1. Locate the VTEC spool valve assembly. This can be found on the top left rear of the cylinder head. Just follow the power steering high pressure  line as it descends, the assembly is in front of it as some point.

2. To create space remove the single 10mm bolt mounting the power steering high pressure line to the valve cover.

3. Remove the electrical connector to the VTEC oil pressure switch (aka valve timing oil pressure switch) and the 2nd connector to the spool valve assembly.

Connectors removed from VTEC spool valve assembly

Connectors removed from VTEC spool valve assembly

4. Remove the three 10mm bolts mounting the spool valve assembly to the cylinder head. This you will need to do mostly by feel due to the location of the 3 bolts (posterior surface of the assembly). Once these bolts are removed the VTEC spool valve assembly should come loose.

5. Remove the old filter from the assembly. On mine, although the assembly came off quite nicely, the caked filter was glued to the mating surface on the cylinder head. I had to pry off by hand.

VTEC Spool Valve Assembly Filter

VTEC Spool Valve Filter removed from the assembly

spool valve assembly filter

Old and new VTEC spool valve assembly filter compared

6. Due to the oily murk on the assembly I decided to give it a thorough bath with electronic contacts cleaner. Note that carb cleaner makes plastic brittle. Therefore if you must use carb cleaner, shield the plastic connectors from the blast. To clean effectively, I removed the single 10mm bolt holding the bracket to the spool valve assembly.

Bolt on mounting bracket

Bolt on mounting bracket

Cleaned up VTEC spool valve assembly!

Cleaned up VTEC spool valve assembly!


7. Place the new filter in the spool valve assembly. It will only fit one way so you wouldn’t have to worry which way the pouched metal mesh should face.

VTEC Solenoid Spool Valve Filter

Filter replaced in groove of VTEC Spool Valve

8. Clean the mating surface on the cylinder head with a clean rag, refit the VTEC spool valve assembly, and follow reverse steps.

NB: Torque on the 3 mounting bolts is 9.8Nm (4cyl). If you do not own a torque wrench this is a bit past hand tight. Torque on V6 models is 22Nm.


  • Ray

    It’s good to note that you should replace the front filter also called the vtc filter. It is in front just behind the belt tensioner which will have to be removed. This, including the vtec filter and o-ring, along with the vtc oil valve o-ring should be checked and replaced. These are usually always the culprits in leaks.

    • Thanks.
      I had replaced the VTC filter previously. The leak from there is quite classical;it will splash over the serpentine belt and also degrade the belt, forming tiny bits of rubbery black stuff. Quite messy.

  • Julie

    Just changed out the entire spool assembly with a brand new Honda unit from the Honda dealer after getting a Code P2646. Also had an oil leak from the unit (cracked and flattened gasket) anyway, the check engine light is still on after starting. What’s up here?

    • Hello Julie,
      Thanks for reaching out. Kindly note that the CEL will NOT immediately go off after replacing a faulty vtec switch. It will take a couple drive cycles.
      If I may ask, what oil weight do you use and how regular are oil change intervals? Thicker oil weights, low oil level or prolonged oil changes are some of the common causes of a P2646. Is the car still in limp mode?

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