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Discussion Starter #1
So quick little story of how this came to happen . My buddy and I did a pull in his 98' wrx sti . We pull back into the parking lot and we notice there is a knocking noise . We drive back to his house a couple blocks away. The knocking or rattling noise only came up at around 2000-3000 rpm . We check fluids in the car and turns out this idiot has barely any oil in his car. We fill it up and run it again . knocking still persists . we decide to replace his filter as well as that was overdue and see if it was a clogged oil filter not getting oil to the engine. We test again and the knocking is still there but now its happening during idle as well. I check the if it was just rattling heat shielding or my downpipe , nope wasn't it. So now I'm wondering what else could I check to see what the cause could be . Plz halp :(
 

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'MURRICA!
Hybrid Camry
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5,700 Posts
Could be.

But it'll be cheaper to replace the engine than to rebuild it.
 

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Premium Member
2001 A.W. L
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13,249 Posts
a knocking engine is caused by a bad bearing, the primary cause for a bearing to let go is a lack of oil.
 

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Premium Member
98 2.5RS - V2 WRX Swap
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1,639 Posts
Its likely that low oil level caused oil starvation at one of the rod bearings. The rod journal probably contacted the bearing and spun it which is preventing oil from reaching the bearing. No oil in journal bearing = knocky knocky.

Whatever you do, do NOT run it anymore. The more you run it, the more metal debris is being pulled into the oil and distributed around the whole engine. This may cause irreparable damage to the engine/turbo.

The guys are probably right, new engine is easiest solution. Sorry bout your luck!
 

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Discussion Starter #8
SO quick question could I be able to change out the bearings with the engine in my car by removing the oil pan ?
 

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Experimenter
Tubaru Pickup
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3,914 Posts
On an oil starve bearing failure, its never just one bearing. The crankshaft is now junk, rods that spun bearing are now out of round and are junk and of course the bearings are junk. Depending on how long you ran the rattle box after it was injured, the bearing material would have spread throughout the oil like others said, this material will score cylinder wall, damage oil pumps, ruin the turbo journal bearings, clog the oil cooler, sometime implode the oil pickup tube, its gets in the lifters, around the cam journals and scores them too.

Can you reuse heads after a spun bearing? Usually. Is the turbo still ok? Maybe.

I've blown a few motors. My advise, get another motor and put it in. After thats done, rebuild whats left of your old motor for next time and to learn some things
 

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95/99 Brighton STi
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2,945 Posts
Oil starvation is not the only cause for rod knock. Pre-ignition due to an aggressive tune, bad gas, etc can lead to a spun rod bearing even with proper oil levels.

Old, thinned out oil or new oil that's too thin can lead to spun beatings/rod knock
 

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My sister gave me her GC8, i drove it 2 weeks ago... Low on oil... Put 2 liters. Today was knocking, carefully went to the gas station, engine went claclaclaclaclaPAK...dead, the oil... Dry as hell.
So i need a new motor.
How do i keep my motor from eating more oil than gasoline?
 

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1995 EZ30 Coupe
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800 Posts
Valve cover gaskets typically leak.
I'm guessing you put the two liters in, then it sat for two weeks, then you drive it and it had no oil? That's a pretty serious leak, more indicative of a loose oil drain plug or a broken oil return hose (if you have a turbo).
If it drank the two liters over a short period of driving, I'd have to guess a combination of the above issues and/or horrifically blown head gaskets and/or completely fried piston rings.
Chances are your new motor won't leak/burn/consume NEARLY as much oil, but check the valve cover gaskets anyway.
 

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Unless you're going to rebuild it yourself 😳 it's time for a new engine , I had a buddy of mine went to look at a subie with the same symptoms and the previous owner told him it was a piston slap, and he bought it😳😳😳 well I told him I should slap you with that same piston 😳😳😳😳
 

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since is my sister's car, she know the guy who rebuilded her engine, personally, i don't know much about him, i gues he fucked up something while rebuilding it.
by the way, she is selling her car for components. and she's looking for something else. we love subaru but these months were a pure pain in the ass. i personally want a subaru but seeing the struggle i give up.
 

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Super Moderator
2000 RSTi
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734 Posts
I'm with Dmljohnson, you can't blame a car company based on a couple used engines.

My old roommate had mk3 supras, he put used turbo engines in his, he'd get anywhere from days to months on those. I helped him install them too. After 3 used engines blowing up (spun bearings and blown head gaskets), he paid a shop that actually had experience with 7mgte's to rebuild his. Well, that engine was awesome, till it's head gasket kept blowing....

My own experience is mostly with Subaru (but I have had a couple blown head gasket 3vz's), you can't trust a used turbo engine. And you can't trust a non-subaru specialist to rebuild a subaru engine, they are way different from most.
 
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