[Maddtvguy86]

So my local tuner told me I had rods let go from cyl 2 and cyl 4! They said at first sight the turbo looked good while removing my engine. They said they can't see the inlet tho yet. Today I called and they said my turbo was garbage that there were metal shavings in it and it cost as much to rebuild as a new one. I have been reading other posts in this and I found this ......

"I saw a lubrication diagram for the EJ series engines awhile back. If memory serves me correct, the heads/turbo are on the same oil circuit and the bottom end is a separate circuit.

Any garbage that the bearings spit up will get dropped back into the sump and screened by the pickup/filter.

Even if a small amount of particulates got into the turbo itself... anything small enough to not cause immediate turbo bearing failure is no worse than metal shavings that get introduced during normal engine break in.

I think the mechanic
a) has no idea what he's talking about
b) is trying to make some more $ off ya
c) all of the above

All the spun bearings I have seen are due to the motor being doomed since day one (improper assembly, poor clearances, etc.) or due to oil starvation or excessive RPM.

Particulates in an engine spin bearings when they get BEHIND the bearing (during assembly) and mess up oiling clearances.

The easiest way to see if it is noise in the short block or valve train is to beg/borrow/steal a timing light.

Move the light around to each plug wire until you get a flash as close to the noise as possible. If you get one flash per noise, it's most likely something in the valvetrain. If you get two noises per flash it is in the short block.

If the noise turns out to be something in the valvetrain you most definately have particulates in the turbo bearings. See my above statement about particulates in the turbo bearings.


So could shavings get in my turbo or is it screened and they are just taking me for a ride ?


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

I'm asking more about the anatomy of
The engine and if shavings are caught before the turbo by any filter


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

Ok, so your not answering my question of if my rods letting go creating metal will or will not in fact spread metal to my turbo. My turbo didn't die from a spun bearing.


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

1) Two rod failures points toward oiling problems. Not for sure, since one bearing being damaged (not necessarily "spun") could have put enough babbitt into the oil that the second bearing suffered, but I would still bet on a failed oil pump, failed/stuck open oil pump bypass valve, or just plain low oil level.

2) Re the turbo, an ounce of data trumps a pound of theory. Why don't you take a look at the thing and see if it spins OK or not? That will tell you a lot. And, yes, a bunch of babbitt in the oil could have messed up the turbo bearing oil flow as well.

3) Cut open the oil filter and see what you have. That will be educational, at least, if not useful in further diagnosis. If there is metal, a magnet will tell you whether it is babbitt or not.

I was running with knock for hundreds of miles before it let go,(oil level was topped off) I was suprised to hear that BOTH driver side rods broke... after reading that there's a filter before the turbo it makes me suspicious that shop is upselling me. First inspection of the turbo was fine on the exhaust side.


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

I guess head work is $750


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

Turbo is good!


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

The turbo has a bearing in it that if dry will make shavings. What happens elsewhere is beside the fact.

Sent from my SAMSUNG-SM-G935A using Tapatalk

What do you think about $5100 in parts alone for a OEM STi shortblock ?


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

Oooo .... Bad idea. But you know that now.

What that knock was doing was pounding babbitt material out of the big-end bearing and putting it into the oil. As someone previously mentioned that may have been enough to clog the filter and cause the filter bypass valve to open. Game over at that point: Then (still guessing a bit) the oil galley to the second rod bearing may have gotten clogged and the rest is history.

Now that you explain, I'm not surprised at all.

Good on you that the turbo is OK. Be very careful, though. Whatever oil passages there are in the turbo itself will have to be very carefully cleaned with brushes, flushed with parts washing fluid, and inspected by a raving paranoid. This may well entail tearing the thing down.

My tuner didn't mention this, thanks!


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

Hundreds of miles with fried bearings? Man, yeah it's completely possible in that length of time the particulate are up the turbo.

Usually with a dead bearing they last hundreds of seconds.

Sent from my SAMSUNG-SM-G935A using Tapatalk

Yes my local mechanic said that he has driven cars with knock for a year or so, granted he said that was about 10k a year.
I thought I would give it a shot until I could afford the repairs


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

I already brought it to my local dyno tuner. I'm not sure they are much better now


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

I'll bite. What can be damaged and how? A head is a casting with a bunch of added holes drilled in it. Not much to damage except by badly overheating it a la head gasket failure or by overenthusiastic porting.

He has commented on my previous post where my first issue was my head gasket leak from my engine into my radiator.


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

Well, I personally wouldn't bother for a street car, but this is also the time for mild specialist tricks like maybe bigger valves or mild porting and polishing and matching the intake manifold.

This is all just General Engine 101. Guys here who have actually done a few of these Soob engines will probably come by with more specific suggestions.

I don't know engine 101 ^^ what would porting and polishing do, that not usually included in re decking ?


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

Contaminated oil can damage a head. Especially if the bearings were shot for that long and you have that much crap lubricating everything.

Sent from my SAMSUNG-SM-G935A using Tapatalk

I thought I was crazy for a second but found out that I had both posts from different forums with you there


Sent from my iPhone using Tapatalk

 

[Maddtvguy86]

Which can and does damage heads. But it in this thread he is asserting that babbitt in the oil can damage a head and I have no idea how that would happen.

I'm guessing that by "decking" you mean taking a cut off the top of the block to increase compression. Like I said, I don't know these Soob engines in detail -- never have had one apart. Sometimes a head is cut for this purpose, too. "Porting and polishing" refers to the intake and exhaust passages in the head and often includes work in the intake manifold. Step one is to open up the passages and smooth out sharp corners to improve gas flow. This is generally done with a die grinder and a carbide cutter. Step two is to go in with sanding rolls and smooth the surfaces of the ports, again to improve gas flow. It needs to be done by an expert, though, because in some heads the ports are better left small to increase exhaust gas velocity for better extraction as the piston passes TDC. The momentum of the gas in the head continues to drag exhaust gas out of the cylinder even though the piston is no longer helping. Kind of like flushing a toilet, actually. An amateur, also, can accidentally cut through the casting into the water jacket, instantly ruining the head.

Thank you for the detailed explanation. By decking I assume the people I am using mean resurfacing to fit the new block with no leaks. I'm
not sure if the compression changes from WRX heads on a STI block, one post was saying it reduces HP but I know nothing about it.


Sent from my iPhone using Tapatalk