This weekend my wife was driving our 04 Subaru outback, while passing a slow moving car, the motor made an odd shutter tap noise while hitting the passing gear. It had a bit of an intermittent shutter noise the remaing 5 miles to town. When we pulled into a gas station the oil light was flickering on and off. After letting it sit, I found it was low on oil (not registering on the dip stick) I added a quart and headed back hom. after that the noise became a light clunk at idle. The clunck disappeared off idle until 2500 rpm. I never lost any performance whatsoever on the drive home, and from the drivers seat of the car you would never know there was a problem. It appears the car as about 2 1/2 quarts low when the problem occured. I checked the timing belt tesioner, everything looked fine (just did timing set and head gaskets 20k ago) I pulled the oil pan today, and there is alot of metal in there. A couple pieces of what appears to be aluminum the size and thickness of finger nail clippings. And alot of smaller to medium size shavings as well, all are non ferous and appear to be aluminum. I checked the rod bearings while in the oil pan and everything appears tight. From what I could see of the wrist pins and piston skirts, everything looked good. I'm not really sure where to go with this project.... I was pretty sure the knock was coming from the front of the motor, but my old man thought it was coming from the back (we both have terrible hearing) it seemed to me to be slighly louder on the drivers side.Any ideas as to where this knock could be coming from would be greatly appreciated.

you only had a little under 2 quarts in the pan.. Hard acceleration the oil pump pickup sucked air and lost oil pressure. Even for a second it was likely a bearing was weak enough to either spin or just get eaten

Those are bearing shavings.

 

Time for a new engine.

 

2-1/2 quarts low is a death sentence when the pan only holds 4-1/2. It was holding less than half of its capacity, and at least a quart of that was in circulation somewhere in the oil feed passages or on its way draining back to the pan.

you would be surprised.. At the TLE, I change oil on lots of subies. Many come in with a quart or less in the pan, still having oil pressure. Some do have engine noise but others don't. Most all are repeat customers.. Given that they leave full of oil, they are leaking or burning a lot in 3500 miles.

Why people don't check their oil is beyond me even on a new vehicle..Takes two minutes to do. You should check your oil at least once a week, Three times a week if it leaks or burns it.

Desertsubaru- Oil was checked last week, and was fine. The car barely used any oil up to this point. 

So, to clarify, I do know thew engine is toast. Is there any specific bearing I should be looking at? I plan to pull the engine this week and get it on the bench. Should I just plan on a replacement engine, or could it be worth fixing?

How many mile on this engine?

engine has 160k. 

If you rebuild this engine go the whole nine yards and do a complete rebuild. Look on carparts.com for a low mileage Junk yard engine. I found a 2.2 with 126 k for $500 bucks with a six month warranty.

Thanks! I will give that a shot.

I'm sorry this happened to you.  For more minor issues I would try Lucas and run synthetic oil for minimum friction.

Put a new Subaru Genuine PCV valve on it while you're at it.  This $12 part could be the source of your sudden oil loss and resulting problems.  Sad, but true.

 

Emily

my 00 legacy ej25 auto trans spun the rod bearing on  #4 at 82k miles.

about 200 miles after i bought it.

 

it started knocking one day, for a little while,

and then quit.

it came back a few days later and then died altogether the same day.

Edited September 29, 201510 yr by johnceggleston

Is it common for the bearings to be composed of aluminum? That's the part that I don't understand. None of the silver colored shavings can be picked up with a magnet.

Have you re-checked the oil since? It might have needed to settle back. I took mine in for new valve stems after getting it and the place did a complimentary inspection. Guy came out and shouted at me "there's no oil in it". I was like, "I just checked it a day ago and it was on the line". He started saying it wasn't even showing on the stick and showed me. I stated I'd look at it when I got home. Got home, parked on level ground, let it sit a few hours and like magic it was back on the line vs. before not being on the stick. Not sure exactly what the deal is as I've checked it other times since after running 5-10 minutes prior and it'll be on the stick. 

Is it common for the bearings to be composed of aluminum? That's the part that I don't understand. None of the silver colored shavings can be picked up with a magnet.

 

I have no idea with these. If you see copper shavings, that's definitely bearing material. Aluminum could be cap material if the bearing actually spun; piston shavings (like say you broke a piston ring and the piston is rubbing on the wall). Only way you'll know for sure is to tear the engine down. Pull the oil pump cover and inspect there too. The cog is steel IIRC, but the cover is aluminum. For all you know, there was aluminum flashing from a poor inspection that broke free and blocked an oil passage or ended up in the oil pump rotor and got crushed.

Thanks for all the advice. I plan on tearing the motor down later this week. I'm curious to see what I find.

Bearing material tends to be copper and lead.

Aluminum can be material from the block where the rod cap is making contact with the block.

Very tight tolerances in there and the rods can hit the side of the block if the bearing totally fails.

I just did an oil on a 06 outback. Flickering oil light, no oil on the stick and no oil in the pan. But it ran and pretty good, except the tell tale sign that the rods were chattering and I shut that thing off as quick as I could before the block windowed from a rod that wanted out

Is it common for the bearings to be composed of aluminum? That's the part that I don't understand. None of the silver colored shavings can be picked up with a magnet.

 

Aluminum is indeed a common component of engine bearings.  That, and copper. 

 

These are the ones which are usually OEM:

 

http://www.mahle-aftermarket.com/na/en/products-&-services/engine-components/light-vehicle/engine-bearings/

So the crank is at the machine shop. It was epic failure of rod bearing number 1 and minor failure of the remaing 3 and every main bearing along the way. Pistons and case all look great, so should be a relatively easy fix. 257 dollars to grind and true the crank, and new rod and main bearings.

Oil starvation is a...

 

Pull the backing plate off the oil pump and make sure the rotor isn't scored, and make sure no bits of metal made it into the passages in the pump.

Oil starvation is a...

 

Pull the backing plate off the oil pump and make sure the rotor isn't scored, and make sure no bits of metal made it into the passages in the pump.

 

Since you obviously have the case apart, use compressed air to blow out all the oil passages as well. (We put ours through a jet tank and ultrasound first, but I realize most people don't have access to those.)  Any time you have bearing failure like that, you have pieces of metal all throughout the system, including the heads.  You don't want oil starvation due to debris to cause a cam to seize in the head too! 

 

Emily

The block halves are going in an engine washer tomorrow, and I will be definitely taking my time cleaning the heads and oil passages. I will be replacing the oil pump as everything goes back together. I am going to do piston, rings, and wristpins as well while I am in there. This has been a great learning experience..... I never again will take oil levels for granted.