Elevated lead levels in oil - Engine on borrowed time?

[PranK]

So, I wish I'd done an oil analysis before changing my turbos because my analysis shows elevated (53 ppm) levels of lead.

I don't have an analysis before this, so there is no trend. I'll do another change and analysis in 5k to establish a trend but I'm curious about whether this is just a sign of a steady decline? I have no knocks and oil pressure seems ok.  Is this something my engine can recover from or is it on borrowed time?

My mechanic did add some additive for stem seals in the last oil change which would be in this analysis. I'm not sure if that would affect anything. 

Also, the oil in this analysis is the first oil change I did with the car so I have no idea how long it had been since the previous one. I was given a service history but I don't fully trust these.

I know we don't have heaps of info and I'm kinda freaking out a bit, maybe prematurely. 

[GTSBoy]

26 minutes ago, PranK said:

My mechanic did add some additive for stem seals in the last oil change which would be in this analysis. I'm not sure if that would affect anything. 

Find out how much lead is in that additive. Lead is normally a no-no, but seeing as it is an "additive" they might be able to get away with relatively low levels in their product, that could then turn up at the ppm level in the bulk oil.

[PranK]

I forgot to mention also that he cut the filter open and saw no glitter at all in there. 

6 minutes ago, GTSBoy said:

Find out how much lead is in that additive. Lead is normally a no-no, but seeing as it is an "additive" they might be able to get away with relatively low levels in their product, that could then turn up at the ppm level in the bulk oil.

Yep, I'l give him a call shortly. Fingers crossed! 

[PranK]

I'm reading that lead is likely from bearings. Can these be caught before it's too late or is it doomed already? 

 

[GTSBoy]

5 minutes ago, PranK said:

I'm reading that lead is likely from bearings. Can these be caught before it's too late or is it doomed already? 

 

Well, yeah, there is a (very thin) layer of soft lead on the surface of bearing shells to provide that first "cushion" against physical contact. Just because it is wearing off doesn't actually mean that the engine is dying. Of course, it can mean that the engine is dying.

If the engine is making no noises and the oil pressure is (mostly, as in most of the time) fine, then it could just be suffering under particular conditions. That could be startup, or maybe at some point in the normal operation cycle - or maybe the Beemer engine suffers under long left hand bend (see, highway on ramp) and the pressure drops. You'd need to try to work out if any such thing is happening and then determine if you need a bigger oil pump, or an Accusump or something.

[PranK]

39 minutes ago, GTSBoy said:

Well, yeah, there is a (very thin) layer of soft lead on the surface of bearing shells to provide that first "cushion" against physical contact. Just because it is wearing off doesn't actually mean that the engine is dying. Of course, it can mean that the engine is dying.

If the engine is making no noises and the oil pressure is (mostly, as in most of the time) fine, then it could just be suffering under particular conditions. That could be startup, or maybe at some point in the normal operation cycle - or maybe the Beemer engine suffers under long left hand bend (see, highway on ramp) and the pressure drops. You'd need to try to work out if any such thing is happening and then determine if you need a bigger oil pump, or an Accusump or something.

My engine has only an oil pressure switch from factory and I've installed an after market sensor that will alert me to pressure loss (https://www.sau.com.au/forums/topic/484431-my-bmw-335i/page/3/) . These engines can definitely feel long left/right handers which is why I added this sensor.

There are no other symptoms at all. No strange noises (in fact after the turbos were replaced the mechanic made a note of how sweet the engine was running), no smoke, no glitter in the filter, nada. I'm just a stress head with car issues, I hate there being anything at all wrong with my cars, even if its basic. I just immediately get anxious and start thinking about catastrophic failure.

 

[Duncan]

Did the oil analysis include the acceptable range for Lead?

Last one i has said 1ppm is the limit and the engine I was testing had 74, 80 and 33 (was the race car, tested from brand new run in engine). It may not help to tell you the engine didn't last long, but they never did back then 

[PranK]

19 minutes ago, Duncan said:

Did the oil analysis include the acceptable range for Lead?

Last one i has said 1ppm is the limit and the engine I was testing had 74, 80 and 33 (was the race car, tested from brand new run in engine). It may not help to tell you the engine didn't last long, but they never did back then 

They didn't. This is their comments;

Quote

 

Lead wear rate abnormal. All other wear levels appear satisfactory for first sample. Silicon level (dirt/sealant material) satisfactory. Water content acceptable. Fuel dilution satisfactory. Viscosity low for specified oil grade. Action: Please confirm oil grade used in this component. Check for lower than typical oil pressure. Check for excessive engine knock at stall speed. As oil and filter(s) already changed, resample at a reduced service interval to monitor and establish wear trend. Note: In the absence of OEM specifications, general severity limits have been applied. 

 

I'm not sure why they don't have the OEM specs. 

[PranK]

I had a thought. I still haven't confirmed what additive was used but, the oil from this analysis was only 5,000 k's old and I believe was Mobil 1. Given that the oil was good and fresh, would there still be wear in the engine?

What I'm trying to articulate is, I understand that internal wear will happen with incorrect viscosity or not changing oil enough (and maybe other reasons also). But would the wear continue to occur when the oil is changed? Surely it would stop wearing, ie the damage was done? If thats the case, could this suggest maybe that the lead count is not wear?

I dont know if that makes sense. It does in my head.

[GTSBoy]

15 minutes ago, PranK said:

But would the wear continue to occur when the oil is changed? Surely it would stop wearing, ie the damage was done? If thats the case, could this suggest maybe that the lead count is not wear?

What has an oil change got to do with whether wear is occurring or not? Wear may be facilitated by oil having been left in too long and broken down - but it is far more likely to be a mechanical issue (ie, pressure).

The thing with the tested oil being only 5000kms old makes it perhaps equally likely to be lead from bearings or lead from the additive.

[PranK]

Ok that makes sense, I was circling around the idea that this kind of wear would only occur with too long intervals between oil changes but I see what you're saying about the cause being something else.

[PranK]

Ok, so I just had a chat with my mechanic. He said there is no real source of lead in the engine, the bearings and pistons are aluminium and the rings I think he said are steel. He doesn't recall what additive he used but that along with the thicker 20w50 he used could be a source of lead.

It's put me at ease a little bit and I guess I'll just have to wait 5000 k's to do another change and see if anything is different. 

I appreciate you guys chiming in. I have a habit of immediately thinking worst case with things like this.

[Predator1]

On 07/05/2024 at 10:25 AM, PranK said:

 

It's put me at ease a little bit and I guess I'll just have to wait 5000 k's to do another change and see if anything is different. 

 

You could just drive it normally and change it earlier. Mine has never crossed 2000k's even 

[PranK]

2 hours ago, Predator1 said:

You could just drive it normally and change it earlier. Mine has never crossed 2000k's even 

Yeah true. 👍

[Duncan]

well, FWIW mechanic is surely not right about the bearings being aluminium, they would be softer; mostly tin, nickel, copper and lead on a steel shell.

[PranK]

19 hours ago, Duncan said:

well, FWIW mechanic is surely not right about the bearings being aluminium, they would be softer; mostly tin, nickel, copper and lead on a steel shell.

Just after I started to feel better about it all.  

[GTSBoy]

I did say there was lead on the face of the bearings right at the start.

[PranK]

I'm trying to find more info about the composition of the bearings. 

I found these ones; "The Upper and Lower bearing shells are comprised of a lead-free, Silver-based tri-metal material designed for extreme load applications." https://www.turnermotorsport.com/p-3929159-king-n55n54-rod-bearing-set-size-050-oversized/

And ChatGPT said; "The overlay material is often a soft metal alloy such as aluminum or a lead-based material."

I'm just going to send myself mad. I'll just drain and analyse in a few thousand k's.

[PranK]

13 minutes ago, GTSBoy said:

I did say there was lead on the face of the bearings right at the start.

I know.  

[GoHashiriya]

The good news is, the quote from my mechanic for N53 bearings was relatively low and he’s fortunately an ex-BMW tech. I also went down this path - engine had a low oil pressure error from a missing cage in the filter housing. I ended up watching a million hours of rebuild videos until my oil analysis came back okay other than a shit tonne of boron *iirc* which was consistent with a leaking oil filter housing gasket. I also recall BMW N series bearings having a different material composition to normal.