[Classic 本田]

How will you prevent it from happening again?

 

[kickascii2000]

How will you prevent it from happening again?

My direct cause was related to the factory harness that connects to the VTEC solenoid and pressure sensor (2-wire). I bought an aftermarket replacement on amazon and also double downed and sealed the top of the sensors with liquid tape; also on amazon. I originally replaced the sensor with an OEM part and that temp fixed it. However with the oem harness, it let water into the new sensor and it failed after a month. Once a sensor is comprimised with water, you need to replace it.

 

[Classic 本田]

My direct cause was related to the factory harness that connects to the VTEC solenoid and pressure sensor (2-wire). I bought an aftermarket replacement on amazon and also double downed and sealed the top of the sensors with liquid tape; also on amazon. I originally replaced the sensor with an OEM part and that temp fixed it. However with the oem harness, it let water into the new sensor and it failed after a month. Once a sensor is comprimised with water, you need to replace it.

Trust me, I know. That’s why we assemble new Honda Genuine connectors here in the shop.

 

[Jeffro]

sprayed aluminum cleaner

What?

.

 

[psychosocial]

What?

.

Its a connector... has metal terminals inside. Aluminum cleaner cleans metal. The terminals were wet and gunky. The aluminum cleaner cleaned the metal, and the alcohol dries the water. I clean stuff for a living you learn tricks as you go along.

 

[psychosocial]

My direct cause was related to the factory harness that connects to the VTEC solenoid and pressure sensor (2-wire). I bought an aftermarket replacement on amazon and also double downed and sealed the top of the sensors with liquid tape; also on amazon. I originally replaced the sensor with an OEM part and that temp fixed it. However with the oem harness, it let water into the new sensor and it failed after a month. Once a sensor is comprimised with water, you need to replace it.

Dont forget to check the rubber seal that seals the hood. I think they call it a Cawl seal. I searched "hood seal honda element" It was a factory honda part and it was very reasonable. Like $25 maybe?

 

[Jeffro]

Did you catch the bit in David's video where he talks about the windshield washer squirter as another source of leak directly above the connector?

I hate silicone caulk. I would use Sashco Lexel to seal that up.
.

 

[psychosocial]

Trust me, I know. That’s why we assemble new Honda Genuine connectors here in the shop.

Yeah.. I just realized who you are. I sent you an email a couple days before I did mine... I wanted to buy the plugs. You didn't respond back so I kept researching and just cleaned mine. Your YT vids are great BTW. Excellent videos indeed.

 

[Jeffro]

metal terminals inside. Aluminum cleaner cleans metal

I would guess it would. First time I've heard of using it on connector terminals in 50 years though!
I'll typically use an electronic cleaner such as De-Oxit Gold.

Have you heard of Stabilant 22 ?

Tell me a brand, I'll put a bottle on my bench.

I know that some cleaners react with metals, but I believe it's the other way around, like don't use toilet bowl cleaner and some popular degreasers on aluminum parts, wheels and such. I think the damage is mostly cosmetic though, just stains them deeply.

 

[jlshuman]

This code is driving me bananas. Car is a 2003 automatic awd EX with approx 158,500 miles. Various other parts have been replaced since 2022, I just didn't list them all out because I didn't think they were relevant.

First occurence was in November 2023, in pouring rain on the interstate. Did an oil change and the problem stopped.

Second time: June 2024. Shop replaced the engine oil pressure switch, VVT solenoid, and the engine temperature gauge. Also got an oil change.

Third time: January 2025. I topped off the oil and it resolved itself.

Fourth: February 2025. Started after fifteen minutes at ~20mph on the interstate. Oil level normal. Resolved itself with no intervention after 3 weeks.

Fifth: Late March 2025. Came on, then turned itself off after a day, then came back on. Oil change resolved it for six weeks.

Sixth: Thursday, May 22, 2025. I'd taken it in to the shop due to cylinder 3 and 4 misfires, (I had also mysteriously lost coolant overnight) which they diagnosed as a bad head gasket and said they wouldn't fix. I got the CEL when leaving and used my new code reader which confirmed P2646 as well as misfire on 3, misfire on 4, and misc misfire (303, 304, 300).

Took it to Shop2 for a second opinion the next day, and they were able to reproduce p2646 but not the misfire codes. They suspected it was the vtech solenoid. Car passed a pressure test and lost no coolant when hot. Shop2 kept it overnight to do a cold pressure test and it passed that too. I picked it up Saturday and p2646 immediately came back. (As expected.)

Shop1's warranty on the vvt solenoid from last June was still good, so I was getting them to replace it for free rather than shelling out for Shop2 to do it. P2646 was the only code from Sunday until Thursday (the 29th) when it was much cooler (mid 60s) and drizzling rain, and I had visible smoke out the tailpipe upon starting. (Sign of a bad head gasket? Normal in these temps? I have no idea.) Got gas and checked the codes again and it was 300, 303, 304 and p2646. Shop1 replaced the VVT solenoid and cleared the codes and while driving home in the pouring rain, P2646 came back on.

Shop1 isn't open on the weekends (M-F 7-6) and I have a 9-5 job during the week, so I really cannot afford to do more of this back and forth. I understand there is no one size fits most answer to this error but:

1. what can I do as a non-mechanic to troubleshoot?
2. what questions do I need to be asking the mechanic next time I have to go back?
3. will replacing the engine solve this problem?

any help is greatly appreciated. Thanks in advance!

I had the same issue. My main problem is the vehicle hadn't been driven in a year. Should have changed the oil and other fluids before resurrecting it as a daily driver. Anyway:

1. Replaced VTEC spool valve assembly (AKA VVT) including new filter.
2. A few hundred miles later P2646 code returned.
3. Changed oil. Removed VVT filter and cleaned. Couple of weeks later error code returned. Hmmm.
4. Did some interwebs searching. Discovered there is another VTEC strainer on these k24 engines. It is located right next to the power steering pump. And unfortunately it requires removing the serpentine belt and steering pump assembly to access the 2nd VTEC filter.
5. Have not had any issues since.

The random misfires and loss of coolant does sound like a head gasket is in your future. Here is a pic of the part from RockAuto.

And a youtube vid on how to do it. It isn't too bad a DIY project and doesn't require any special tools.

This code is driving me bananas. Car is a 2003 automatic awd EX with approx 158,500 miles. Various other parts have been replaced since 2022, I just didn't list them all out because I didn't think they were relevant.

First occurence was in November 2023, in pouring rain on the interstate. Did an oil change and the problem stopped.

Second time: June 2024. Shop replaced the engine oil pressure switch, VVT solenoid, and the engine temperature gauge. Also got an oil change.

Third time: January 2025. I topped off the oil and it resolved itself.

Fourth: February 2025. Started after fifteen minutes at ~20mph on the interstate. Oil level normal. Resolved itself with no intervention after 3 weeks.

Fifth: Late March 2025. Came on, then turned itself off after a day, then came back on. Oil change resolved it for six weeks.

Sixth: Thursday, May 22, 2025. I'd taken it in to the shop due to cylinder 3 and 4 misfires, (I had also mysteriously lost coolant overnight) which they diagnosed as a bad head gasket and said they wouldn't fix. I got the CEL when leaving and used my new code reader which confirmed P2646 as well as misfire on 3, misfire on 4, and misc misfire (303, 304, 300).

Took it to Shop2 for a second opinion the next day, and they were able to reproduce p2646 but not the misfire codes. They suspected it was the vtech solenoid. Car passed a pressure test and lost no coolant when hot. Shop2 kept it overnight to do a cold pressure test and it passed that too. I picked it up Saturday and p2646 immediately came back. (As expected.)

Shop1's warranty on the vvt solenoid from last June was still good, so I was getting them to replace it for free rather than shelling out for Shop2 to do it. P2646 was the only code from Sunday until Thursday (the 29th) when it was much cooler (mid 60s) and drizzling rain, and I had visible smoke out the tailpipe upon starting. (Sign of a bad head gasket? Normal in these temps? I have no idea.) Got gas and checked the codes again and it was 300, 303, 304 and p2646. Shop1 replaced the VVT solenoid and cleared the codes and while driving home in the pouring rain, P2646 came back on.

Shop1 isn't open on the weekends (M-F 7-6) and I have a 9-5 job during the week, so I really cannot afford to do more of this back and forth. I understand there is no one size fits most answer to this error but:

1. what can I do as a non-mechanic to troubleshoot?
2. what questions do I need to be asking the mechanic next time I have to go back?
3. will replacing the engine solve this problem?

any help is greatly appreciated. Thanks in advance!

I had the same issue. My main problem was the vehicle hadn't been driven in a year. Should have changed the oil and other fluids before resurrecting it as a daily driver. Anyway:

1. Replaced VTEC spool valve assembly (AKA VVT) including new filter.
2. A few hundred miles later P2646 code returned.
3. Changed oil. Removed VVT filter and cleaned. Couple of weeks later error code returned. Hmmm.
4. Did some interwebs searching. Discovered there is another VTEC strainer on these k24 engines. It is located right next to the power steering pump. And unfortunately it requires removing the serpentine belt and steering pump assembly to access the 2nd VTEC filter.
5. Have not had any issues since.

The random misfires and loss of coolant does sound like a head gasket is in your future. Here is a pic of the part from RockAuto.

And a youtube vid on how to do it. It isn't too bad a DIY project and doesn't require any special tools.

 

[sonicbutslow]

Not sure if this warrants another P2647 post so I will add to this thread.

Preface: Gas cap error light comes on intermittently a week or so prior. Clean it off and it goes off and comes back and goes off and then stays off.

The Story: Driving home and starts bucking after taking off from an intersection, I slow up and it stops while throwing VSA, !, and CEL. Awesome. Drove fine but would buck and lose power at 2700+ rpms/never made it past 3000. Drove for an hour. Let car cool off. Started it and in P could rev well past 3000. Only CEL on at this point. Shut off VSA and drove with no issues, exceeding 3000 rpms. Stopped after an hour. Checked out a venue (still getting home at some point). Drove with VSA on and only the CEL on with no bucking and no problems accelerating. No issues minus CEL which I tested when I got home and checked the CEL. The wiper sprayer is still leaking. I had put silicone sauce around it but it has all gone away. What should I seal that with?

ELE: 2007 FWD, 154,444 miles

Symptoms: Bucking and power loss around 2700 rpms, gas cap light (possibly irrelevant) Code: P2647

Steps toward solution:
0.5. Seal windshield wiper sprayer
1. Clean connections/seal connections
2. Clean/replace VVT Screen
3. Clean/replace the other screen? (This one doesn't look fun)
4. Replace connections
5. Rebuild Vtec (according to Clint on Youtube)
6. Replace Vtec with OEM Is this the correct path?

Really not looking to take it to a shop. Should I reset the code and see if it comes back. The severity of my code is 2 of 3 so I don't want to mess my car up.

 

[Jeffro]

Gas cap error light

I don't think my '08 has any such thing.

Tell me what this is please.

.

 

[sonicbutslow]

I don't think my '08 has any such thing.

Tell me what this is please.

.

Its not a light but it displays where your odometer is and it is cleared the same way you would clear a trip. I don't know what it should be called. My bad. I don't even recall what it says but it says something about gas cap error or something like that. Mine is a 2007

 

[Jeffro]

Its not a light but it displays where your odometer is and it is cleared the same way you would clear a trip. I don't know what it should be called. My bad. I don't even recall what it says but it says something about gas cap error or something like that. Mine is a 2007

Hmmm... can't recall ever seeing that! I'll have to look tomorrow!

.

 

[sonicbutslow]

Not sure if this warrants another P2647 post so I will add to this thread.

Preface: Gas cap error light comes on intermittently a week or so prior. Clean it off and it goes off and comes back and goes off and then stays off.

The Story: Driving home and starts bucking after taking off from an intersection, I slow up and it stops while throwing VSA, !, and CEL. Awesome. Drove fine but would buck and lose power at 2700+ rpms/never made it past 3000. Drove for an hour. Let car cool off. Started it and in P could rev well past 3000. Only CEL on at this point. Shut off VSA and drove with no issues, exceeding 3000 rpms. Stopped after an hour. Checked out a venue (still getting home at some point). Drove with VSA on and only the CEL on with no bucking and no problems accelerating. No issues minus CEL which I tested when I got home and checked the CEL. The wiper sprayer is still leaking. I had put silicone sauce around it but it has all gone away. What should I seal that with?

ELE: 2007 FWD, 154,444 miles

Symptoms: Bucking and power loss around 2700 rpms, gas cap light (possibly irrelevant) Code: P2647

Steps toward solution:
0.5. Seal windshield wiper sprayer
1. Clean connections/seal connections
2. Clean/replace VVT Screen
3. Clean/replace the other screen? (This one doesn't look fun)
4. Replace connections
5. Rebuild Vtec (according to Clint on Youtube)
6. Replace Vtec with OEM Is this the correct path?

Really not looking to take it to a shop. Should I reset the code and see if it comes back. The severity of my code is 2 of 3 so I don't want to mess my car up.

Update:

1. Sealed the windshield wiper sprayer with gasket maker (couldn't find high temp silicone sealant)
2. sprayed the two connections that got dripped on with electrical cleaner
3. coated the connector side and wired back with dielectric grease once they were cleaned out
4. Drove it for hmmmmm 40 miles or so with no issues (over an hour of driving in town and highway)

Currently believing the issue is resolved for now, I figure there will be a time to replace the connectors in the future.

 

[hphil300]

same prob...

I've had the same problem and they said the code showed that it was the vtec sensor, so they replaced the switch/sensor. Did the same thing after the replacement, so they said it was the fuel pump, replaced that. Still doing the same thing. Now they say it may just be a bad connection or cylanoid.....hit and miss sure hurts the pocket book. Of course min's out of warranty

mine did the same thing, changed vtech valve checked wiring, found that leaving the small code reader that i bought from walmart for 20 bucks, plugged in solved the problem.but if the car is left for a few weeks without use ,the battery runs down. I think the true fix would be replace ecm but too much money runs great as is , just have to mess with it a little ie plug in/unplug code reader

 

[BumbleBee]

the two things that i've seen cause this code are low oil level, and a bad vtec pressure switch. 9 times out of 10, it's a customer who's 2000 miles overdue for an oil change, and they're over a quart low.

i've also seen a few leaky vtec solenoid gaskets aka spool valve gasket. check that too.

Hie!! I’ve gotten this code over and over!! The first time I changed the solenoid and screens! Fixed it for a while and it came back on…then I changed the oil pressure switch itself… and it fixed for less than a day. It will not go over 3000 rpm’s or 65 MPH before it bucks. I’ve done NUMEROUS oil changes and it still comes on! Any suggestions?