New to me M3, sparkly oil, looking for impressions

[Pklauser]

Hey all, I wish my introduction to the forum was on a more positive note lol.

I bought a 2003 M3 a month ago and have been sorting out its various odds and ends, most concerning of which is the sparkly oil I just drained out of it. There are some details to consider here, but I'll try to be brief:

• Car currently has 130K
• Received a "low mileage bottom end, new rod bearings, new chain guides, and had head rebuilt including Beisan Vanos" at 124K (word of PO)
• Oil pan and valve cover were off just before I bought the car because the PO was adjusting the valves and checking the rod bearings because he had "forgotten that the bearings had been done" (I know, I know, wtf is that? Should I have walked away? Maybe, but I like steel gray with no rust, a stick, and a clean carfax, so here we are)

I changed the oil as soon as I bought the car and honestly wasn't shining a light directly on the oil so I didn't notice anything strange. It wasn't until now, ~300 miles later, that I was replacing the o-rings on the oil cooler and noticed the sparkliness of the oil, visible with a light shining directly on it.

(yep, that's my stove, was trying to see if maybe they were just little air bubbles by heating the oil a little, they're not)

It's easiest to observe in this video:

https://photos.app.goo.gl/HifdrTHvywnNyqtR7

I took a large magnet to the side of my drain pan and can definitely see some movement in the fluid, but it honestly just looks like a shadow moving, it doesn't appear that all of the glitter moves with the magnet. It's all so fine, it's pretty challenging to really see.

Curious as to where the oil is coming from, I do a cursory check in the oil cap and notice this:



Not sure if that's anything to be concerned about, but it does look a little more scored than I'd expect, maybe that's the source of the glitter? Not sure what would cause that other than low oil pressure. Could someone being an idiot about valve adjustments cause that to happen? I've been noticing some hair-brained things on this car Eg. the wrong bolt used on the oil cooler lines causing it to leak, and wouldn't be shocked if the PO goofed this up too.

I also chopped up the oil filter and checked the pleats. I found some black non-ferrous flecks like this:


Not sure if that's carbon? I did also manage to find 2 small metal slivers that danced with my magnet. So small I didn't even see them until I waved my magnet underneath the filter and saw it move.


The engine runs great and doesn't make any strange noises, so I don't think anything's fubar'd yet, and I'd like to keep it that way.

Currently devising my plan of attack here, I'm thinking I'll at least be putting clean oil back in and doing an oil pressure test to validate that there's nothing wacky going on there. From there maybe pull the valve cover and get a better look at both cams?

I'm leery of dropping the oil pan to inspect the rod bearings, my concern being that I'll end up pulling the whole engine out anyway, and I'll have wasted all the pain and misery of dropping the front suspension. Without knowing where the metal is coming from, and given the weird history of this motor, pulling out the whole thing would give me the most flexibility.


I'm curious what other people's take on the scenario is. Is there any chance this is just some residual schmutz in the motor that will go away with a couple oil changes? My thought is: no, since I have this many sparkles after under 1K miles on the oil, but what say you?

[TexaZ3]

That oil does look very strange... What is it? Why is it so....pale?

[jbfrancis3]

I don't see how you avoid pulling both the valve cover and oil pan. I think you wondered if this was risk to begin with, given the odd stuff during the buying process. So just get in there and you'll get a full assessment over everything. We can speculate here all day, run Blackstone tests, etc. but that won't give you a full understanding. Also depends on your goals with the car and if its longer term. Thats my $0.02

[BMWahba]

Do you have any insight as to why the bottom end was replaced with a lower mile one? Or why the head was rebuilt? Did the motor see some sort of failure previously and what you’re seeing in the oil is the evidence of a few cut corners when they rebuilt it?

[Pklauser]

That oil does look very strange... What is it? Why is it so....pale?

It's Liqui-Moly 10W60, it's gold in most circumstances, I think the contrast, metal, and flash in that photo may just be playing games.

I don't see how you avoid pulling both the valve cover and oil pan. I think you wondered if this was risk to begin with, given the odd stuff during the buying process. So just get in there and you'll get a full assessment over everything. We can speculate here all day, run Blackstone tests, etc. but that won't give you a full understanding. Also depends on your goals with the car and if its longer term. Thats my $0.02

Yea, I'm just wondering if it's worth pulling the whole engine out to make those assessments and further repairs easier. Are there other known places that could be throwing metal into the oil other than the cams and lower-end bearings? I'm thinking, what if I pull the pan and the valve cover and everything looks hunky dory? Just trying to mentally prepare myself for whatever road I'm about to go down.

As far as longer-term goals, I plan on keeping this car a long time and running in HPDEs with it, so getting this squared away properly is important to me.

Do you have any insight as to why the bottom end was replaced with a lower mile one? Or why the head was rebuilt? Did the motor see some sort of failure previously and what you’re seeing in the oil is the evidence of a few cut corners when they rebuilt it?

Great question, apparently the motor had failed before, leading to that rebuild work, though this was with an owner previous to even the one I bought it from. Could be cut corners. When you say that I guess you're thinking it could be pretty much anything at that point?

Any thoughts on anything I should check out before I start pulling things apart? Like I said I want to check oil pressure, since I can't test that once I start pulling things off, anything else?

[jet_dogg]

Sounds like a lot of guessing at this point. Good luck.

[Pklauser]

Sounds like a lot of guessing at this point. Good luck.

You're not wrong. I'll start the investigation process and try to keep this thread updated. It'll be slow since I've also gotta fix my E30's leaking transmission before Lime Rock in a few weeks!

Thanks all for the reality check.

[sapote]

the sparkly oil I just drained out of it

Are those flakes attached to a magnet? If not then they are copper which mostly came from crank or rod bearings.
The cam lobe looks bad, but good used cams are relatively cheap on Ebay. The worn rocker followers need replaced.
The cut out filter doesn't look bad at all. This is a good news.
"Received a "low mileage bottom end" -- meaning it has a replacement block and stuffs inside?

I would check oil pressure; drop the pan and remove a few rod and main bearings; remove valve cover and look over everything in there. These are easier than pull the engine out.

[Pklauser]

"Received a "low mileage bottom end" -- meaning it has a replacement block and stuffs inside?

That's my assumption. This car used to be a Dinan S3 car, which as I interpret, means it had a supercharger. The car also used to have a bolt-in harness bar as I've recently discovered while poking around. I'm guessing the old bottom end just grenaded while being pushed hard on track.

I would check oil pressure; drop the pan and remove a few rod and main bearings; remove valve cover and look over everything in there. These are easier than pull the engine out.

That's pretty much my current game plan, sounds good to me. I assume wear on the main bearing caps should be pretty indicative of wear on the top-side bearings as well? Wondering if it would also be worth pushing some rods around to see the top of those bearings, obviously not an option on the mains, but I understand the rod-side rod bearings receive more of the force during operation and could be more worn.

I'll have to do some reading, not sure if there's any sort of procedure involved with removing just a few main caps. Seems like the kind of thing where they're all torqued in a specific sequence and I don't want to cause any other issues checking things out.

[Pklauser]

Just got done checking the oil pressure with a mechanical gauge hooked up in place of the dummy-light sender. Having that unplugged means no light shows on the dash by the way, seems like the opposite failure mode I would expect...

Anyway, once the oil was heated up to just a touch under 210F on the dash I was sitting at 22 psi. Revving it brought the oil pressure up to 70 psi by 4K where it seemed to level off. Didn't take it much further than 4K at 10pm for my neighbor's sake.

These numbers all seem good to me following the ol' 10psi/1K rpm rule of thumb, and I assume the 70 psi is just the bypass pressure on the oil pump, which also seems inline with other motors I've seen.

All-in-all good things to see, but the mystery continues. Next step will be to pull the valve cover off and see what I find there!

[heinzboehmer]

Wow I can't believe the failure mode for the oil pressure light is to have it off. Kinda sketch.

I also want to have a go at guessing what the cause is. If the car previously spun a bearing and the oil cooler wasn't replaced when the engine was rebuilt, then it is probably still filled with metallic particles and reintroducing them into the engine.

[sapote]

I assume wear on the main bearing caps should be pretty indicative of wear on the top-side bearings as well? Wondering if it would also be worth pushing some rods around to see the top of those bearings, obviously not an option on the mains,.

If bottom bearing half looks good this doesn't mean top half is OK, as the top has more load and worn more. So it's just easy to to push the rod/piston up and look at the top half bearing too.

Re on the main, the bottom halves carried more load and so it they look OK then top halves should be OK too.

[Pklauser]

I also want to have a go at guessing what the cause is. If the car previously spun a bearing and the oil cooler wasn't replaced when the engine was rebuilt, then it is probably still filled with metallic particles and reintroducing them into the engine.

This thought definitely crossed my mind, though I'm not really 100% sure what to do to verify. I could pull the cooler and flush it outside the car, but I'd have no way of knowing if the metal coming out was from before, or is being put there now.

Replacing the cooler now could result in it filling back up with metal particles if the current motor is in-fact shedding.

I'll keep this in mind, but at this point I'm going to continue forward with checking out the valve cover and oil pan unless there's some other way to approach the oil cooler idea that I'm not thinking of.

[heinzboehmer]

I'll keep this in mind, but at this point I'm going to continue forward with checking out the valve cover and oil pan unless there's some other way to approach the oil cooler idea that I'm not thinking of.

I don't think there's any way to know what's going on without doing what you're planning on doing. I was just guessing at the cause for the fun of it

Hopefully you get your answer soon!

[Pklauser]

Pulled the valve cover today. Cam lobes don't look too hot, still not clear what would cause the wear I'm seeing on them. Here's the worst one:



I can feel the gold (?) pits with my fingernail, anyone know what I'm looking at? I thought the cams were steel all the way through. Cam followers look similarly worn and almost...rusty? Could just be the coloring of some stuff that didn't come off when this head was last cleaned, as it clearly has been in recent mileage.





The little pools of oil in the head seem to have a higher concentration of metal in them than the oil I pulled out of the pan. When sticking a magnet in these pools, I can pick up a fair amount of metal powder, but not all. Note the "sludge" on top of the cam caps in the earlier picture isn't actually sludge, it's metal 😦. (Hello apparent ARP head studs)



Is there any risk of pulling off just one of the cam caps as long as the lobes near it aren't loaded up? Curious to check the journals here, but these are long cams and I know they can be brittle.

Because the metal found in the oil in the head is more obviously magnetic, that makes me wonder if this is in fact the cams that are throwing this metal. They don't seem _that_ bad to me, but I'm wondering if they're worn far enough that they're through their hardened layer and are shedding their softer metal now. I checked clearance on a few of the valves, something the PO allegedly did, and they were within spec, so this doesn't appear to be the immediate issue.

Also this is the cylinder 1 exhaust cam follower area, is the casting on the head really that rough from factory? It looks like someone scratched it up a little more with a screwdriver or something, presumably to remove the cam follower retainer, but the moon-shaped cutout looks odd to me, as well as the jaggedness to the left of it, below the cam cap.



Attached some additional lobe photos for good measure