Metal flakes in engine oil

chixwithtrix · 12-27-2009, 10:39 PM

I started to change the oil on my 2006 YFZ 450 for the first time since I bought it from the previous owner.

Once I finally removed the stripped bolt from the engine oil reservoir (previous owner was an idiot) the oil that came out had flakes of metal in it. Removed the tank and there was tons of fairly large metal flakes in it and on the coarse filter on the dry sump pickup. None of the large flakes were in the engine crankcase or in the oil filter, but all of the oil had small flecks of metal when drained that gave it a metallic sheen. The large flakes varied in color

Engine starts up on the first try normally and runs strong. Like I said this is its first oil change since I bought it. Previous owner had a high comp piston installed about two years ago. Has a loud knocking sound, but I've heard that the yfz engine sometimes has a loud knocking sound when its fine.

Where should I be looking for problems?

Grayish engine oil color

Bits of crap on the pickup. As you can see some of it is different colors

More bits from the reservoir tank

Magnetic flakes from reservoir tank, not aluminum.

Metallic sheen of the oil

**leveldrummer** · 12-27-2009, 11:17 PM

wow, thats alot of metal, its a very good chance that the motor exploded before, and that is when he took the opportunity to put a high comp in during rebuild. i would dump the oil, fill it and imediately dump it again, then fill it, run it for a couple minutes, then dump it, new filters each time, get the cheapest motor cycle oil you can find designed for a wet clutch. put a lot through it and try to clean as much metal out as you can. then i would just ride it and see what happens.

unless you have the cash to do a rebuild, catching a problem early couple cost a lot less then a motor locking up, but there might not be any damage at all, its a tough call...

chixwithtrix · 12-28-2009, 12:02 AM

I know its never been rebuilt, only the high comp piston installed by a shop. Some people have been saying I should be weary of the knocking sound, might be signs of bearing or rod failure?

**Bowtie** · 12-28-2009, 12:16 AM

Quote: Originally Posted by chixwithtrix

I know its never been rebuilt, only the high comp piston installed by a shop. Some people have been saying I should be weary of the knocking sound, might be signs of bearing or rod failure?

With out hearing it, it's hard to say, what you think is a knock, others may not. I would suggest taking it to a couple of shops and say, hey, listen to this, what do you think.

chixwithtrix · 12-28-2009, 01:29 PM

I called a repair shop around me and they said that the knocking would possibly be rod knock it if got louder or softer when I went to let out the clutch and gave power with the front brakes on. From what I remember it doesn't change any pitch and is not irregular. It makes the knocking noise in sync with something else.

Being the the shavings are steel they also said that it might be from the transmission. Sometimes I have trouble when shifting from first to second and it only goes into neutral and never makes it to second, sorta like it hangs or is sticky.

I'm about to go pick up some more oil and do a couple of oil changes. Will try and get a video of what the knocking sounds like.

chixwithtrix · 12-28-2009, 06:52 PM

Here is the video I took after the first oil change. I do have to say the video makes the knock sound sound worse since the microphone is cheap, but you'll get the idea.

Testing by putting in 1st gear, hand on the front brake, let out the clutch until it starts engaging, and give throttle - was recommended to me by the local engine tech. 00:20 through 00:25 especially you can hear the knock sound get louder as I increase the throttle, then drops to almost nill when throttle is let off, then comes back to the regular idle knock sound. The engine tech said that if the knocking sound increased or decreased during this test that it could be a sign of rod knock.

When I listened for where the knocking sound is coming from, it does not seem to be coming from the bottom end though. I can hear it better when I listened around the head and mid area of the engine...maybe wrist pin noise? Do your engines sound like this?

Here is the video

YouTube - YFZ 450 engine knock sound

**Bowtie** · 12-28-2009, 07:39 PM

Hard to say, but it doesn't sound right, start the tear down, head and base gaskets are cheap. Pull the head and jug and check the wrist pin and at the same time you can check for any play on the rod/crank end.

chixwithtrix · 12-29-2009, 08:24 AM

yeah, looks like I'll be starting later today on the teardown, thanks.

**Bowtie** · 12-29-2009, 08:28 AM

do you have a shop manual? If not, get one, you will need it for this.

joey moheit · 12-29-2009, 06:33 PM

im no pro but i had a knocking sound from my top end and i bought a rod from autozone and it looks like a stethoscope with a rod at the end it sounded like my tappets or rocker arms that hang over the springs were hitting their covers i took off the intake cover and i saw a mark in the inside of the cover wher the arm was hitting. just adjusted the valves tappets and the noise stopped and ran smoother