Hi all, I just replaced the heads on my 1999 4runner due to my previous pair being cracked.

Started it up for 1 minute and then flushed the oil. To my horror the oil was full of sparkles (small aluminum flakes, non-ferrous). I filled the engine up with oil again and ran the engine for 1 minute. Drained the oil and more aluminum flakes came out. Most of flakes are very fine.

Prior to replacing the heads the oil was always clean.

Any thoughts? Obviously this isnt good, but I'm wondering if anyone has ran into this before.

My thoughts are junk heads. Probably big box store bad quality rebullds...

Edit: As if that's all you changed, the filings had to be in the head from mfg or remfg.

No where else could it have come from?

The block is cast, and nothing else was touched.

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I came from a long ago era, that a rule of thumb for newly machined engine parts, you need to wash it out thoroughly before assembly.

Machine shops got parts fairly clean of the machining process. Then it would be up to you to really wash out more of the finer pieces.

Don't know what normal actions on the valve train would cause fine aluminum dust to be dislodged into the oil.

Are our seats cast directly to the head or do we have inserts? If the former that's practically the only thing I could see happening - lash is off and valves are contacting with too much pressure. But even then I would think it's more likely to deform the seat than create shavings.
I'm leaning more towards what HiLife said. As someone who is a cylinder head technician and had made ton of aluminum auto parts I could absolutely see a lazy shop leaving it full of dust. That stuff can be pretty tricky to get out and if people go willy nilly with an air gun while machining it tends to send chips into the oil and water galleys.
Other than that perhaps a valve stem was too big for the valve guide (if those are casted aluminum and not steel inserts as well)

Nothing surprises me anymore. They could have at least told the OP to thoroughly clean the heads before installation. I would hope all maching shops would do that.


Heck one time, I found sand blasting sand inside a remfg caliper that I re o-ring the pistons on.

I agree with the others the aluminum is from the heads. I just hope all other things are in spec. When things like this occur, it always makes me wonder..

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Hate to ask the obvious but When you installed these heads did you pour oil into them BEFORE putting the valve covers back on?


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We mostly got the stp thick stuff and coated the camshafts and the bearing cups with it to prevent dry start. The last camshafts I pulled that is. Worked really well until the oil can get everywhere again.

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Thanks for the replies. I never thought to clean the heads. I have been trying to think what would be wearing so fast, so I guess it makes sense that a bunch of left over material could have been in the oil galleys. Is does seem like a lot of material though...

welfare_wag- I was pretty liberal with the oil during assembly and there was assembly lube on the cams etc, but maybe I missed something.

I will take the covers off tomorrow and see if there is anything obviously wrong. If everything does seem ok what do you think my next steps should be? Am I hosed? I was thinking flushing the engine with some cheap oil several times to see if it clears up the shavings.

Flushing the engine a few times with oil and filers is a good idea. Hoping none of the journals plug with shavings. That's what I would do and hope for the best.



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So now op reports shiny glitter in oil.
One gotta hope that the oil filter would clean that all up.

It's really hard cleaning it out when the metal makes it to the oil pan.

Even though it's soft aluminum, frequent oil filter changes would be easiest option. Cause pending on how much material and the size of it, is floating around, it would be bad to now clogged oil filter. Worst yet is the bypass valve would open and sent the all that junk through the system.

Maybe this is stupid to say but isn’t SOME shavings sorta kinda normal for this scenario? It could be as simple as the new heads wearing in but I don’t know enough to tell you one way or another. Obviously If your oil is completely full of them that’s not good but aren’t some to be expected as it “breaks in”?

I will say that when I did my heads I don’t recall seeing shavings but it was 3 years ago now. I even split the filter to make sure and don’t recall seeing anything about after 10 miles of driving


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Depends on how many sparkles. For new engine heads or block I'd expect some glitter like you get when breaking in a new engine. Hard to say if it's normal, to an extent you can expect glitter.

If the metal was ferrous or gold in color I would be much more concerned since a replaced 5vz head shouldn't be wearing materials with such properties.

IMO the aluminum is old machining material or a cam bearing.

You said it had plenty of prelube. Did you shim the valves or were they done at the shop?

Did you prelube the engine before starting?


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I am also in the camp that the shavings were in the head and released when the oil circulated. Camshafts are extremely hard and don't shave, they crack and split. Ask me how I know! Beyond that, you didn't touch anything else with a head job. I would replace the oil filter now and put fresh oil in. Run it for a few hundred miles and then check again and see if there are more or less. Hopefully less and if yes then at 500 miles do another oil and filter change and just check on it once in a while. I am confident the flakes will be gone.

Have you also checked your coolant? It's not as important but there is very likely to be shavings in your coolant as well.

Wouldn't the oil filter stop the metal flakes/pieces?