Aluminum in oil in TCS

[cazman]

My engine was rebuilt a while ago, but has never had many miles on it. I have about 500 miles on it with new oil since I have owned it. I put in a Oberg disk oil filter. These make it very easy to check particles in your oil at any time.  I have all of a sudden, aluminum shavings in the oil. Not the kind of small particles that come from bearings, but the kind that you would see from a file. I would say that something is rubbing. Maybe a chain tensioner? I am not that familiar with these twin cams yet, so I do not know where the usual suspect would be.

[Pfreen]

Can you post a photo?
Also, could it be shavings from machining the head?  I would think if it is the timing chain you would hear a bad noise.

[EuropaTC]

There's a wear pad of hard rubber on the front cover opposite the chain adjustment and I have seen these fail in the past. It's even documented in Miles Wilkins book about a faulty batch that was around at one point. My experience came because a mate had his fail in less than 1,000 miles after rebuild and he bought the plate in for me to look at.

However as has been mentioned, firstly the chain needs to be well out of adjustment to hit this plate and secondly you'd hear the noise. But if you're not familiar with the engine it would be easy to think it's normal. Possibly checked by pulling the cam cover and a good torch.

Brian

[cazman]

I know this is hard to see, but it does remind me of cast aluminum shavings. If you have ever milled aluminum and had to clean up your oily machine, sometimes you end up with a paste-like substance. That is what this is. There was a lot more, but the wind picked up and sent my napkin sailing.


I do not hear any weird noises though.

[BDA]

That looks pretty bad! I would carefully check under the cam cover but I suspect the more likely place there is a problem is in the front timing cover. I might also try using a stethoscope around anything that is aluminum.

At the same time, those shavings don't look like anything I would expect from wear in the engine. Could it be possible that it is machining swarf that was not cleaned out? I think it would make sense to drop the pan and also inspect your oil pump.

[cazman]

The top looks clean. I would expect to see aluminum sprayed onto the cover and chain if the chain was rubbing. The chain is tight.

I just changed the oil and it too looks clean. I have already had the oil pan off to put a baffle in and that was clean then. I might run it a bit and see if the particles accumulate again.

[jbcollier]

Unless you are using an electron microscope, those are pretty big filings.  Use a big screwdriver and see how much fore/aft play there is in the crank.  Good?  Leave the valve cover off and drop the pan again.  Look very closely at the front and rear of the crank.  Use a bright light!  Pull a main cap and a rod cap off and inspect the bearings.  If they are badly scored, you’re pulling it down regardless.   Look good?  Pull the oil pump and inspect it carefully as everything that got caught in the oil filter went through the pump.

All looks good?  Probably whoever did the engine didn’t clean it properly and the machining swarf is finding it’s way out.  I would change the oil and filter every 500 miles for 2K or so, examining the filter each time.  If it stays clear, thank your proctologist for having the foresight to stick a horse shoe up where it’s been useful.

Otherwise, you have the same luck as most of us and you need to strip the engine and find the issue.

[jbcollier]

PS: Oberg oil filters do not have a very large surface area and are not suitable for long oil change intervals.  Great for racing but not as much so on the street.  Just a heads up in case everyone was going to rush out and fit one.

[cazman]

An update to my problem with aluminum bits in my oil filter.

Since I have this Oberg filter, it is easy to keep checking the filter surface and the last two checks, after an oil change, the amount has been trending to zero aluminum debris. Interestingly, I have also found bits of other junk like RTV/gasket maker and even red cloth fibers (dreaded shop rag).

I have rebuilt many engines, but this is the first time I have used an oil filter system like the Oberg. As we all know, the rule for engine assembly is Cleanliness and I can really see what sloppy prep can contribute to the lubrication system. The disadvantage of the Oberg is that you have to clean the filter more often, but it is nice to get a peak on what is going on inside the engine at anytime. 

[BDA]

Seeing RTV and shop rag fibers, not to mention the chunks of aluminum, would be really scary! I think that might motivate me to look at the rod and main bearings. I would also take JB’s advice and fit a more appropriate filter after you’re sure your motor is clean inside.

[cazman]

I may do that, but right now there is no evidence of bearing wear. The filter is good for what I am doing (track days). The filter is much more efficient than a common paper filter, it just does not hold as much particulate. 

[jbcollier]

For what Cazman is doing, an Oberg filter is a good choice.

[cazman]

I have an update to my woes of metal in my oil. The metal filings have not stopped, so I had to pull the pan and really see what was going on. The real problem are the rods. The bearings apparently did not spin and cause wear like I would have expected, that is probably why the filings looked so strange. Not the usual very tiny particles, but larger flattened pieces. After, a couple of weeks of diagnosing after tearing the motor apart we figured out that the last person that rebuilt the motor chased the connecting rod-end threads with a standard machine tap. Apparently, the Twin Cam rods have rolled J threads and should not be chased with a standard tap. So, at high RPM the threads were giving away allowing the rod to knock and beat the bearing.

So, its new rods. The crank is good though.

 

[BDA]

That's really unfortunate! At least your crank is good.

[jbcollier]

Glad you guys persisted and found the issue before things went really awry.