this is complicated, but if you know what im talking about you will understand...

a while back i got my car running great, no leaks, misses, or problems.

i took it for a tune, and somewhere in between me arriving and the car being put on the dyno something happened. the tuner started to do a small pull and as soon as he hits boost, this horrible rattle noise comes from the car...

we look at some numbers, and the knock sensor was knocking max and pulling all the timing. so i was sent home till i figure this out. its been months and im still stumped...

but i have it narroed down, so please help. there is a mivec oil control valve/solenoid located below the intake manifold above the alternator. its about 3-1/2 inches long. it has one bolt holding it in. about two inches of the valve goes into the motor while the solenoid part sticks outside obviously.

if i unplug this sensor, the car runs great.

but with this sensor plugged in ,this is what i think is happening. something is making the solenoid/valve freak out and chatter loudly, causing the knock sensor to pick up the foreign noise and pull all the timing.

so i replaced this mivec oil control valve/sensor with no luck. i also changed my mass air flow sensor with no luck....

PLEASE help me figure this out, so i can get a proper tune. thanks in advance...josh

 

If the knock sensor was out, did you properly torque it?

May not be a terrible idea to check for pinched or damaged wires near the sensor.

 

i did not take the knock sensor out, i replaced the mivec oil control valve...
i was thinking last night, maybe i could trace the wires, but does anyone know what controls this valve? how does it work?

 

i dont even know where to look to educate myself on how it operates. where do you guys look when you dont know how something works?

 

Shop manual would help you out. You can get them on CD pretty cheap. Or someone may be able to get you one if they had an email address

 

well if anyone can help me out i would appreciate it... considering i spent 700 bucks and didnt fix a thing yet.

stoshevo@gmail.com

so nobody has any ideas on my issuses???

 

bump

 

that valve it controlled by the ecu. it feeds oil pressure to the cam gear to move it. first thing that comes to mind is piston to valve contact. second is a loose timing chain but that wouldnt explain why you unplug it and it runs better. if the motor sounds like hell under boost then i doubt its a little solonoid. you can hardly hear them working when the engine is not running let alone when the engine is reved up. reset the ecu and install the tune again.

 

i just fowarded you a copy of the fsm, i think its all there... hope this helps

 

nevermind, it might just be the engine mechanical.. the full version is on my laptop getting repaired, if you still need it in a few days pm me and ill email you the full fsm

 

Maybe if it controls the Mivec cam gear, maybe that assy is faulty. When it gets oil pressure maybe its loose or something
Check the Mivec cam gear

 

well none of that sounds minor, haha i hope i dont hurt anything else... but remember plugged in it acts up with brief times of running good. but if i unplug it, everything is great...

 

Does it sound like it misses at all, idle, cruise or WOT? Who did the cam install?

 

as soon as i hit boost it pulls all the timing. its kinda hard to explain what thats like. it will run full boost but have no power and you can feel the car holding itself back... thats the best i can explain it...

on a second note in neutral i can take the rpms up SLOW all the way with no issues.

and i installed the cams 2 years ago, the problem started within the last six months...

 

I have seen bad lifters do this. Generally they'll cause issues even out of boost, sometimes hang a valve and miss, etc.