Chrisheff

Picked up a 98 civic EX for dirt cheap so obviously it needs some work. Got a code p1259. Need to clean or possibly buy a new vtec valve or solinoid. I'd like to try and clean it first. Just have no clue how. I'm sure it's in this forum somewhere but of course I can't find it. Can someone/ anyone give me the how to link!

ezone

Got oil?


There are published test procedures for that code that could lead to a successful diagnostic conclusion without guessing at expensive parts.
Why this? What kind of symptom does it have?

Chrisheff

Does have oil. Every time I clear the code it comes back on after a few min. Was told to try and clean it before replacing.

ezone

Got Freeze Frame data to post?

If you can just let it idle and the code sets then your computer isn't seeing the state of the pressure switch correctly. Open circuit, broken wire, disconnected switch?

Chrisheff

The light doesn't come on while at idle. As soon as I drive after a few min.

ezone

So you have to get the RPM up over about 3000 before the light comes on?


Have you tested to see if the solenoid works?
That it actually does something when it's activated?
That it is getting a signal from the computer to activate, and that signal is reaching the solenoid?
That the pressure switch changes states immediately (within 5 seconds) after the solenoid is activated, while the engine RPM is sufficiently high to have good oil pressure?
And that change of state signal is also reaching the computer?


The reason I say this is the VTEC solenoids have been fairly reliable, and they are expensive IMHO to just guess at.
The pressure switch is only an occasional failure, and the couple I have witnessed were very random and intermittent when they would fail. Meaning they worked most of the time.
Switch can be purchased without buying the whole VTEC valve.



Big issue in my area is rodents that eat wires just about anywhere on the cars.


To clean, simply unbolt the valve from the side of the cylinder head (3 bolts) and inspect the small filter screen embedded in the rubber gasket. Replace the gasket, it comes with a new screen.

Chrisheff

Yes sir over 3000 light comes back on.
I just tested the solinoid and that works. But that's only by applying voltage
Directly to the solinoid while unplugged. I'm solo working on this so its hard for me to test while at 3000rpm. Guess I better get some help. Other then that do you recommend I pull and attempt to clean?


Also the radiator fan doesn't turn on and car overheats after a while. Tested fan and it works. Tested fan relay also good. Any thoughts on other things to test?

I appreciate all the advice

ezone

Ok if you can operate the solenoid by yourself......

Got your volt/ohm meter too? Connect that to the pressure switch on the VTEC unit. One on each terminal, set on ohms/continuity test.



Run the engine at 3000 (operate throttle by hand) and apply voltage to the solenoid. Listen for the sound of the engine to change as VTEC engages.

Ohmmeter should change within a couple seconds of powering up that solenoid. (zero ohms --> open circuit)


How it works:

Solenoid opens the oil pressure passage to the valvetrain

Oil passage feeds oil pressure to the valve actuator system.

System actuates the valves if there is enough oil pressure (IIRC over 50 PSI).

Pressure switch tells the computer if the system actuated or not, once the oil pressure has made its way throughout the valvetrain.

If it all works manually, then you may be down to testing wiring.
Hard to say. About the only thing you can really clean is the screen (part of the gasket) and since the gasket is rubber it should be replaced if it has any age on it. It can be a huge oil leak when it leaks, and after a few years in the engine the rubber should be hard as a rock.


I personally would test it first, see if it works or not.....If it doesn't work or acts like an oil pressure feed problem then I would pull it....(The testing as described is easy for me especially when I can use a scanner to watch the pressure switch.)

Find the temperature switch (for the fan) in the thermostat housing.
Disconnect the 2 wire connector.
Ignition key: ON
Jumper the 2 terminals in the connector (touch both of the terminals with a paper clip?). That should engage the relay and turn the fan on. If it runs then yo may be down to checking if the temp sensor is any good or if the system has a huge air bubble in it..

HTH