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well....crap. please help


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Well, in his case, he also got lower compression results after installing his head gasket. Engine did start though, but ran poorly according to him. As you saw, he put another head gasket on it, and the car ran fine after that. Not sure if your head gasket is the reason why you have low compression. But at this point, I am not sure what else to check.
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I will also add this piece of info I found from the Internets :rolleyes:

 

Title of thread: Will a Leak Down test always show a blown head gasket?

 

Answer from a Nasioc forum member:

to answer your question, craig, no.

 

leakdown tests are in the 100 psi range.

 

combustion chamber pressures under load are many times that, in the 500-1k psi range easily.

 

as you can imagine it is possible to have a HG leak that only manifests itself under load.

 

 

I have never really thought about that before, but that sounds right to me. In any case, I hope it won't come down to tearing down the engine once again...

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Kind of hard to do on a S-AVCS.

 

OK, stranger things have happened sometimes, so I wouldn't rule out anything at the moment.

 

On the positive side the leakdown test indicates that there's no expensive mechanical stuff going on.

 

Considering that the compression figures varies so much my guess would still be that it's a timing issue.

 

And no chance that you did mix up the intake sprockets? Since I have never removed them I'm not even sure if it's possible or not. Or if the AVCS was incorrectly installed on the sprocket?

 

I just try to raise questions that may seem stupid, but it's all the pesky details that can lead to a stupid error that can be the culprit in these cases.

 

Looking at the service manual it states:

NOTE:

Do not confuse the cam sprockets (LH) and (RH)

during installation.

So it's probably possible to mix them up.

 

See page 1756 here: http://www.bedug.com/pics/Subaru/2005/2005.pdf

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Are the compression tests being done with the throttle plate "verified" wide open?

 

Pull your Throttle Body hose and have someone sit in the driver's seat, with the key "on" and then floor the accelerator pedal. The TP should open. If not, then that's what I'd check. Alternatively, with no one available, you could use your phone's camera, positioned to video the TB area while you do it from the seat.

 

Limited air to compress, reduced compression numbers.

 

Have you tried to start it, or just doing diagnostics on it?

- Pro amore Dei et patriam et populum -
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Verified the correct cam sprockets are installed on their respective sides. The left side sprockets are physically smaller in width than the right side. Impossible to swap intake and exhaust cams since the intake,cam is longer due to the presence of the cam position sensor. The intake cam just wouldn't fit in the exhaust slot.

 

I habe not physically verified the throttle position in the open position, but i can hear the the plate amd tps turn when I apply the pedal. Typically. Open throttle only changes compression numbers by 10psi or so, so i wouldn't expect to see a significant change anyway

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I still have the feeling that it's something off with the timing and that it has something to do with the sprockets and their mounting on the camshafts or possibly crankshaft - was the crankshaft sprocket ever removed?

 

There's a far fetched thought that the key locking the crankshaft sprocket to the right position is missing.

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Leak-down is showing good numbers, so rings, and HGs (somewhat) all appear good.

 

Cannot imagine the rings are failing on the compression.

 

Timing seems to be right, because LDT #s are good and the valves would have to be closed for that to happen.

 

And you LDT'd using the timing marks, so I'd rule out timing issues based on that test. Unless it's 180* out, which, again, everything lines up, so that makes no sense.

 

That said, your cranking video is definitely sounding like compression is off in at least two, possibly three cylinders.

 

So, if timing is right, fuel is available and spark is present, there should at be some form of engine firing, even if rough.

 

That there's not, seems to point to the ECU not receiving proper sensor inputs; the ECU is not getting what it needs to send the "fire" signal.

- Pro amore Dei et patriam et populum -
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Yep! But...

Leak-down is showing good numbers, so rings, and HGs (somewhat) all appear good.

 

Cannot imagine the rings are failing on the compression.

 

Timing seems to be right, because LDT #s are good and the valves would have to be closed for that to happen.

 

And you LDT'd using the timing marks, so I'd rule out timing issues based on that test. Unless it's 180* out, which, again, everything lines up, so that makes no sense.

 

So, it's not firing even once, which it would even with low compression...it wouldn't be happy, but it would fire unless the ECU is not getting the data it needs.

 

Are the "position" sensors new, or just R&R'd?

- Pro amore Dei et patriam et populum -
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After i got it to fire over, I immediately shut it off since I know the coolant still needed to be filled and burped. I also needed to hook up the power steering, alternator, and AC. Put everything back together and fired it up so i could burp the coolant. The,engine,sounded,pretty good at idle but as soon as I gave it a little gas, after the rpms came,down, the,motor bogged way down and started missing on cyl2&4. Code present as well for the,misfire. It's also making a weird ticking noise that I'm not so sure is valves, but kinda sounds like a TOB.
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Usually, it will bog down a little bit right after an ecu reset at idle (if you give it a little gas), unless you let the car idle for a pretty long time.

And misfires occuring on a given bank is also a sign of timing issue, most of the time. Are you able to log the misfire count live? Or are you just being able to check CEL codes?

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