At what lead level do you swap rod bearings?

[eocrm3]

I recently received my first oil analysis from Blackstone on my 2010 m3 with 55,100 miles.

The oil sample was taken from oil with 3,700 miles on it. All levels were at average readings.....the only slightly elevated level was the lead level which read at 9 (7 being the average).

I wanted to know at what lead level should I be concerned and replace rod bearings....is 9 high enough to merit replacing the bearings?

Thanks guys.

[eocrm3]

Forgot to add.....

I don't track the car, and it is completely stock.

I purchased it at about 40k miles.....so don't know if it was tracked before then, but it was a 1 owner m3 with all service up to date when I purchased it.

I've been changing the oil out every 3500 to 4500 miles since I purchased it.

[dparm]

Until you get several analyses under your belt, it's impossible to say. There isn't really a hard limit anyway.

The whole point of UOAs is to establish a baseline and monitor trends. You should not panic just from a single report. Even Blackstone admits you can get something known as particle streaking which is basically a "false positive" and shows an incorrectly-elevated level.

[tom @ eas]

Originally Posted by dparm

Until you get several analyses under your belt, it's impossible to say. There isn't really a hard limit anyway.

The whole point of UOAs is to establish a baseline and monitor trends. You should not panic just from a single report. Even Blackstone admits you can get something known as particle streaking which is basically a "false positive" and shows an incorrectly-elevated level.

+1. Very well put.