oh the joys of a knocking engine

[lord flashheart]

so i got the car back from the shop and a week later what happens? yes. im sitting at a light at 4 in the morning and the car begins to shutter.
the light turns green and i begin to pull thru the intersection and as the RPMs come up i can start to hear the light knocking noise. im a block away from home so i coast to my home. the shuttering has gone. and at an idle there is no knocking to be herd.
as the RPMs come up around 2k-3k the knock becomes clear. opon closer inspection of the car i discover the oil is low.. and there is a leaking seal under the car. (but i havent had any oil on the ground under my parking spot except just the past few days, so i assumed someone else had been parking in my spot while i was at school on account of there being no reserved parking. but i usually get the same spot.) the knock is not terribly loud. ive herd much MUCH worse. but its still a knock. so i pulled codes and i got the P0021 (intake camshaft position timing over-advanced). i cleared the code, put some more oil in it, started it up and let it run for a few minutes. still getting a knock at about 3k. i haven't had the time to really dig into this yet but so far my thoughts are:
1 the timing had a temporary malfunction and advanced the timing to far and bent a valve and now the timing has corrected itself but because the valve is bent it wont close all the way. causing the knock.

2 the low oil press is causing the VVT to not be able to correct it self and in the upper RPMs the valve is hitting the piston.

3 the OCV (oil control valve) is malfunctioning causing the VVT to malfuction.

4 the vvt cam itself is having issues.

5 the oil line for the VVT is clogged.

6 im completely wrong and its something worse.

am i missing something?

im planning on grabbing a timing light and checking to see if it is advanced or not. cuz if its not the i suspect scenario #1
anyone got some ideas/thoughts?

[Cervantes]

i just had this happen to me...i ended up having to get a new engine...

[lord flashheart]

yeah im looking in to a new motor right now.
im curious about my options.
EJ255 rebuild vs.
EZ30D swap vs.
EJ253 swap vs.
POSSIBLE EJ257
anyone got pro vs cons on these options.

[httrdd]

H6= Instant torque! ;)

[lord flashheart]

i know right! im talking about the time/money/reliability pros and cons. power is on the back burner.

[darryl]

the shop you took it to did they do anything that would cause this problem because if they did i would take it back and make them fix it right you know

[lord flashheart]

the shop you took it to did they do anything that would cause this problem because if they did i would take it back and make them fix it right you know

Nah.. i wish i could blame them. it was a auto body shop from when my car got rear ended. (although they did screw up the paint job and im spose to take it in next week so they can fix it.)
on a side note, i think i am going to try and get rid of this car. cuz progressive said they will compensate me for the amount my
vehicle has depreciated due to the accident. (it says on carfax that it had frame damage due to a little dent that was repaired.)

[02_Legacy]

I was just thinking, could the knock sensor think that rod knock or whatever you are hearing is knock caused by advanced timing and then set the code.
Instead of the way you are figuring it (the code messed something up causing the knock) could it be opposite, (the knock occured causing the code.)
I do not know if the is plausible or not but I was just throwing it out there.

[TGX4776]

If it was a circut malfuntion or some sort like that then it is just the sensor.

[lord flashheart]

well i thought about that, however i doubt that the knock would cause that particular code. that code comes from the timing it self.
the computer is constantly changing it if the knock caused that code it probably be more like a P0325 knock sensor.
but the i called my buddy at the dealer and he says most of the time knocks come from the bottom end. and he says he thinks its a rod bearing.

[TGX4776]

I bad knock sensor can cause your car to knock my improperly changing the mixture. My knock sensor went yesterday do o did some research on it.

[lord flashheart]

interesting... when it stops raining i will probably go drain the oil to see if there is metal in it.

[TGX4776]

Damn phone spelling.

[lord flashheart]

haha i understood what u were getting at.
i talked to the local subie dealer, he says the ez30 wont bolt up to the trans in my car.

[Reuben]

EZ30's plug in man, yes there's some difference, the biggest though will be having to find a radiator that will fit.

But it's a full converision, you need to re-loom and buy a standalone aftermarket ECU. (I recomend link G3's or G4's, as one of the locals down here has worked with link to get them to properly support AVLS)

Go to Clubsub.org.nz, there's some info there on the conversion.

[lord flashheart]

hmmm interesting. wha do u think a ez30 swap would cost in contrast to the ej253?

[Reuben]

If you're in NZ, it can be done for $6000NZD, which is $5000NZD more than converting to single turbo.

But as you're not in NZ, and you don't have twin turbo, these numbers are useless to yah. And no, nobody turbo converts their N/A's here, as it makes as much sense as putting your balls in a vice. So i can't even say "going EZ30 will be X% more or less than a standard turbo swap"

I'm going to guess the turbo swap will be cheaper and easier though. Easier to buy parts, don't need to custom make exhausts and radiator stuff, you can run a turbo engine on it's factory ECU etc. etc. etc.

[lord flashheart]

can the EJ255 ECU run a EJ257?

[Reuben]

It'll plug in and run, but the compression will be way out. Just get whatever ECU matches your engine.

[lord flashheart]

what about the wiring harness? would i need to swap that? i just REALLY dont wanna do a ton of wiring.

[lord flashheart]

i want something as close to plug-n-play as possible. i hate wiring.....

[chuckthefuk]

Pros and Cons huuuu...

What about down-time.. EG/EZ motors are fun but they are projects not "rebuilds/repairs"

Why bother rebuilding the EJ255 when you can just grab a EJ257 block and run that with the EJ255 heads and accessories. Less downtime and very reliable. Simple-plug-n-play. The block itself has very few sensors so it should be a snap to install.

I would still do more research but I have personally seen this done on many 06' WRX who want to upgrade to a stronger block.

EJ255 vs EJ257
http://forums.nasioc.org/forums/showthr ... ?t=1667168 (http://forums.nasioc.org/forums/showthread.php?t=1667168)

EJ257 parts and upgrade info
http://forums.nasioc.com/forums/showthr ... ?t=1887375 (http://forums.nasioc.com/forums/showthread.php?t=1887375)

There are many compression debates about EJ257 block w/ EJ255 heads... some argue some don't.. no one has real world issues.

-Chuck

[lord flashheart]

down time isn't as big of deal. i have my truck and i use my girlfriends car as well.
yeah i talked to a engine builder/tuner company (metric motors) in town and they sell STi short blocks with upgraded pistions and rod bearings for $1800 and they tell me its good for about 400HP
but, im still wondering how much it would cost me to rebuild it.. i imagine a good 1000 bucks.
cuz this repair is cutting DEEP into my already small rally car budget....