Used Oil Analysis report on high mileage 4.0 sohc

[Maniak]

Since the 4.0 sohc in our 2006 mustang is now over 300k miles I figured it was time to do a used oil analysis to see if I need to change the oil change interval we have been using. I "aim" to change the oil between 6k and 8k miles.

I managed to pull a sample at 6,200 miles this time and I sent it off to BlackStone Labs for a test, including TBN.

It looks like our motor is still holding up.

I'll try to get the sample around 8k miles next time just to verify the 8k interval is fine...

Oh yea, they put "semi-synthetic" on the report but it is actually full synthetic.

~Mark

 

[RangerX]

I don't know oil tests, what's TBN?
And why the high level of calcium, of all things? Where does that come from?
Thanks Mark.

 

[Maniak]

As I understand it, the calcium comes from the oil. I don't know how much it had when fresh so I cant compare it. TBN is how much lofe is left in the oil. You want it higher than 1.0.

~Mark

 

[colintrax]

Looks like your mustang is running great. And with over 300K miles, that's impressive.

 

[RangerX]

I was curious so I googled TBN and found this: http://www.truckinginfo.com/blog/lu...d-tan-in-oil-analysis-what-do-these-mean.aspx
Might help anyone else who doesn't know.

 

[Josh P]

That oil has a lot of life left in it and that motor is tight.

 

[RangerX]

Mark, have you done a similar test on your Explorer's high mileage 4.0 ohv?

 

[Maniak]

While the X has just < 400k miles on it, the motor only has just < 45k miles on it since I rebuilt it.

At 355k miles I was mixing coolant and oil and I figured it was a good time to rebuild (actually built a motor I got from an ex EF member). My issue was just a cracked head and when I took the motor apart it was still looking good but by then I already had the new motor built. I pulled some bearing caps and looked at the cross hatch still on the cylinder walls but that was about the extent of the teardown on the short block on the old motor.

~Mark

 

[Maniak]

Got another UOA back. This was was pulled at 323,146 miles and was in the motor for 8,100 miles (I didn't send a sample in on the last oil change).

I'm probably going to stick with the 8k mile oil change as that's been the target for the oil changes. I start to think about it at 7k miles have it done before 9k miles.

~Mark