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LoBuk FTW
00 RS
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680 Posts
Discussion Starter #1 (Edited)
Edit: Pistons hit the valves! Help!

Okay, so... What Subaru has determined is that the piston actually comes out of the block 'too' far and smacks the valves. Is this a normally occuring thing or what? Would thicker head gaskets solve this? (See B1Bflyers post below)

Thoughts?
 

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Registered
1998 Forester on Orange 57F
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4,129 Posts
MeanBaby013 said:
Just rebuilt the damn thing.. Leave it to Subaru to not fix something properly..
The bearings might have went out from knock. Is your car tuned properly? The other option is when it was rebuilt it was not cleaned properly. Like if the block failed before there is metal bits that end up everywhere. And they hide in the oilpump and turbo and bearings. Could cause premature failure. The only way to tell now is to disassemble. The problem is if a shop screwed up they will be looking to blame it on you.
 

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LoBuk FTW
00 RS
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680 Posts
Discussion Starter #7
Well, here's an update for anyone that may have been following, or trying to help.

We started the car up again today, and drove it around for a bit. The noise is no longer prominent at idle, but begins to become apparent around 2500 rpm.
 

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LoBuk FTW
00 RS
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680 Posts
Discussion Starter #9
Each flywheel bolt was torque to 52 lbs per subaru specs. Dont think those woulda come loose with that amount of torque. We did the screwdriver trick, but really couldnt pinpoint anything; never done that before, so it was a little tricky.
 

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LoBuk FTW
00 RS
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680 Posts
Discussion Starter #11
Another update for those who care:

Subaru pulled my valve cover and let the engine run and it was loud as all hell. They determined it to be head noise, and are 95% sure its not rod knock or piston slap.

They will be pulling the head tomorrow, and going through each valve. They 'think' it is a bent valve or two. Hence why the noise is not really there at idle, because the valves are not put under too much stress. Once stress is added, the bent valve starts binding up, and clattering.

I'll keep you all updated.
 

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Never-Ending Project
Type R Project
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511 Posts
The sound in the video is of the pistons on the passenger side striking the bottom of the head. Subaru pulled the head and noticed the "stamp" from the top of the pistons indented into the bottom of the head.

Here's my questions for you JDM pros out there. (keep in mind I am poor at using the proper names for engine components so I'll probably be overly descriptive)

The Subie tech said he's never seen a Subaru engine with pistons that cleared the top of the deck on the block. Meaning when these pistons are at the top of their stroke, they are beyond the plane of the deck. This means that when they put the stock 02 wrx headgaskets on with the EJ20G heads, there wasn't enough clearance for the piston. Is this normal for the JDM EJ20h block? If it were only one piston doing it, I'd say a bad bearing is allowing it to travel too far, but its both #1 and #3. They didn't take the other side off since the passenger side is where the noise was coming from. I don't know what we'll see if we pull the other side, but if we need new head gaskets, it's got to come off anyway.

Even the EJ20G pistons stop about 1/8 of an inch below the deck, so any advice or ideas on what is wrong, or how to fix this would be greatly appreciated.

Ryan
 
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