Z4M Blackstone report shows high sodium and iron

I've now had my 2007 Z4MC's oil analyzed twice at Blackstone. Below is the 2nd and most recent report from 23,800 miles.



The Iron and Sodium content is high. Blackstone suggests coolant leak for the Sodium and gave some possible break-in explanation for the Iron in the first report.

Have any of you seen these high levels before? Any advice?

The car is just a daily driver.

---Michael

Originally Posted by cmichaelo

I've now had my 2007 Z4MC's oil analyzed twice at Blackstone. Below is the 2nd and most recent report from 23,800 miles.

The Iron and Sodium content is high. Blackstone suggests coolant leak for the Sodium and gave some possible break-in explanation for the Iron in the first report.

Have any of you seen these high levels before? Any advice?

The car is just a daily driver.

---Michael

My five tests.

Now why couldn't my car look like that? That is near impeccable results.

Does anyone have any clues to the high Iron and Sodium in my analysis?

---Michael

You almost certainly have a head gasket breach. One nice thing about oil analysis, is that it will detect minute tace amounts, well before a problem becomes epic. This is your opportunity to correct the problem.

I got consecutive reports of high sodium on my 99 (then supercharged) and all normal pressurizing/leak-down tests came back normal. I changed the headgasket for a MLS type, and that cleared up the problem. Mine was apparently only leaking during periods of high boost, so I could not replicate the condition with testing devices.

The iron? Who knows, maybe dilution of the oil due to coolant. Fix one (1) problem, and you may cure the other.

Originally Posted by Randy Forbes

You almost certainly have a head gasket breach. One nice thing about oil analysis, is that it will detect minute tace amounts, well before a problem becomes epic. This is your opportunity to correct the problem.

I got consecutive reports of high sodium on my 99 (then supercharged) and all normal pressurizing/leak-down tests came back normal. I changed the headgasket for a MLS type, and that cleared up the problem. Mine was apparently only leaking during periods of high boost, so I could not replicate the condition with testing devices.

The iron? Who knows, maybe dilution of the oil due to coolant. Fix one (1) problem, and you may cure the other.

Randy,

Thanks.

I was afraid of those exact words..."head gasket".

Could it also be due to that the cylinder head wasn't torqued down properly and has come loose ever so slightly?

Also, and this may be a totally nutty thought...but is there any chance that the [oiled] BMC air I've been using could have given off Sodium and it was sucked in? I'm asking, since it's the only engine modificaiton I've done that could conceivably affect the oil.

---Michael

I had high sodium values for a couple of samples and those dropped off so I am not thinking about it at this time. I also changed the coolant before the last sample and have also done 2 track days on this oil. Planning to do another 2 days at Summit Main this coming weekend and then will change the oil and get it analysed. My bigger problem is occasional higher lead values due to track days but not high enough to worry at this time.

I will most likely get Randy to install new bearings for me this fall if the lead numbers start to go up again ...

Sodium is an additive in some oils. Are you using the mega-baller Castrol as recommended? Valvoline does use sodium, I believe, as do a few others. Keep an eye on it, but don't go panicking yet. Some engines just produce a few different things. I haven't tested mine yet. :scurred:

Thanks pal and boon,

Boon, I'm using the specific Castrol oil as recommended by BMW.

Pal, are you using the recommended Castrol oil as well?

I checked my coolant level a few days ago (cold engine, 80F air). It was low but within range. The top of the red stick was a few mm below the rim of the opening. I took a picture of it so I can keep an eye on it from now on.

Any chance the plastic container from Blackstone gives off Sodium? My oil sat in the container for about a week before sending it to Blackstone.

---Michael

So far I have been using Castrol TWS 10w60 but plan to use Greddy Racing 10w60 for one change this year. I have posted a Blackstone sample of this oil in a separate thread so that a used sample will have some baseline data for chemicals.

Have Blackstone re-run. Sometimes there are "issues" with their tests. If you ask and question the results, they are often more than willing to re-run the test.

When I was getting the high sodium readings, Blackstone asked for a virgin (fresh/clean) sample of the oil I was using. Sodium was ruled out in the Castrol Syntec 10w/40.