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Hey guys,

So I've got a little bit of a problem. About a month ago, I had a Honda dealer replace my head gasket, as I've had overheating problems several months before hand. Not twenty miles out of the dealer, I get a check engine light, this being P2646. The car falls right on it's face when I hit 4K RPM, but only when the car is really warmed up and the oil runs thin. Plus my MPG dropped significantly.

I've replaced the VTEC solenoid, changed the oil the factory (which is 5W-20 for my car) and still nothing. Maybe there's debris in the oil passages from when they changed the gasket but I have no idea what else I can do. I've already put in like 1500 bucks into the car, I can't spend much more on it. I've looked all over the web and they all tell me the same things but those don't work.

Also occasionally my CEL would randomly go away for 15-20 minutes and then come back on. When it turns off, the symptoms go away. I'm thinking it might be a faulty connection. Does anyone know of any and all connectors that are related to VTEC other than the sensor switch?

Any help would be much appreciated!

Thanks.

EDIT: Here's a list of things I've already done:
*Replaced VTEC solenoid and cleaned VTEC screen
*Replaced the VTEC oil pressure switch
*Oil change with 5W-20 synthetic and genuine oil filter
*Checked wiring from VTEC oil pressure switch connector all the way to ECU

 
Rep Power: 518

What did the dealership say about the problem when you took the car back the following day to be rechecked?

 
Rep Power: 518

Did you search this forum for your code?

You should have found threads like this:
https://www.civicforums.com/forums/3...ml#post4694759

 
Rep Power: 0

I took it to them four times and never got a definite answer. The first time (the day after the CEL came on), they said it was probably a loose wire or a connector that was forgotten. That wasn't the case. The second time they just cleared the codes, topped off the oil, and told me other unrelated problems, which I have fixed. Then the last two times were exactly the same :they topped off the oil and just suggested a new VTEC solenoid (which didn't work) and eventually a new engine because they didn't bother looking for more than a half hour.

 
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Yeah, I saw those links. I removed the valve cover and unfortunately the bolt was still there. Occasionally the light would just go away from 15 minutes and then come back on, which I don't think a bolt would cause that.

 
Rep Power: 518

Well.....that makes it sound like you may have an oil pressure problem.
50 PSI @ 3000 RPM is the minimum spec.


FIRST question: Does the engine have a genuine Honda oil filter on it?
More than once I've seen VTEC faults corrected with a genuine Honda oil filter on several different engines.


A real VTEC oil pressure test could be done which would involve some time and effort, and if it comes down to unusually low pressure then an engine replacement may be the correct fix.

HOWEVER......If oil pressure is too low.......you could try switching to a heavier oil just to see what happens.


Another thought: If someone had all the rocker shafts and arms off of the head when it was sent to the machine shop, if ANY of those little bitty pistons and springs popped out of any of the rocker arms and got lost, that would be a place for the VTEC system lose hydraulic oil pressure and cause for a fault code.

 
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So I've been using a FRAM oil filter ever since I've owned the car, which has been about two years now and I've never had a problem. Before this mess, I used 10w-40 oil without any problems. Only after my CEL came on, I bumped down to 5W-20, as using the wrong oil viscosity may cause a CEL to be shown. That wasn't the case. The only way to check if those springs are missing is taking the whole engine apart, huh? Should I bump up the a thicker oil than 5w-20 but lower than 10w-40? Just to see what happens. Or borrow an OBD scanner to get live readings from the sensors?

 
Rep Power: 518

You said the dealer did a head gasket job, as far as I'm concerned an oil change is part of any head gasket job I do.
So what oil filter is on it right now?

Famous last words.



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Did you set this same VTEC code while using 10w40, and was that before the head gasket job?

IDK....I'd want to run pressure checks before deciding to pull the valve cover, but I bet you could use a real thin feeler gauge to check if the pistons are all present in the rocker arms, or maybe even be able to see all of them.
I don't know if an average scanner would be able to read these, or be fast enough to read them without a lot of lag. the system is simple enough to use 2 test lights to watch the operation though, one to see the ON command for the solenoid, and another to read if the pressure switch changed states when the solenoid was activated.
Oil pressure would have to be read with a mechanical gauge.

 
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Yes the dealer did the gasket job and I opted out of an oil change because i was tring to cut costs down. I did it myself the same day. It's still on a FRAM oil filter. I changed it about 300 miles ago, before the problems arose.

Yes, I did get the VTEC code with 10w-40 but that was after the head gasket job. My only problem before they replaced it was overheating, which has been fixed after the job. Before the job, I ran 10W-40 without any problems.

And how would I be able to wire the lights to the solenoid and the switch?

Thanks so much for suggesting all these things.

 
Rep Power: 142

When a new employee starts at the dealership I tell them all the same thing. I state very clearly and repeatedly that if I say the sentence "I've never had a problem with this before" or I've never had a problem doing it this way before." I tell them that if I say either of those things that I am NOT serious. I have worked with a lot of hacks that use those phrases to justify hack repair.

A couple weeks ago we had a customer buy a new battery. Cost is $130 or so, no sure exactly. The tech working on the car was going to drive a nail in between the negative terminal and the brand new battery post to get it to tighten up instead of using a proper battery terminal shim. His response was that he has always done it that way and that his aunts van had been like that for years. Just because it has worked in the past doesn't mean that it is good or proper.

just saying.

 
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I mean, do you think that using the wrong oil and oil filter put lots of stress on everything and eventually broke it down to where it is now? Cause I've definitely considered that.