Fresh engine, second oil change, newbie needs some help

[tomato]

Hi there! Brand new guy, kinda new at the UOA stuff, and I probably did it wrong. This is a rebuilt b25 BMW (1996). Customer brought to me to tune (dyno - efi), and it was being odd. Basically, wets the plugs easy, inconstant cold compression, slow crank when warm and so on. It had idle time on it and they drove around the block a few times, they then changed the oil and brought it to me.

I ran it under varying loads to 3500 rpm until it hit operating temp. Let it cool. Next day, pulled it to 4500 rpm under heavy load a half dozen times, cycling heat from 160 to 200. Still unhappy with it's behavior, almost like it gets tight when warm. not enough to seize, but to slow cranker. Anyway Dropped a quart from the oil pan into a clean container, used a clean plastic syringe to pull an oil sample from about the middle.

The results look high for metals, and I don't know what oil they used.

Should I worry? Or change the oil, and finish running it out?

 

[sloinker]

I'm not so sure the metal numbers are too high considering it was a fresh rebuild. Lots of Zinc/Calcium/Boron looks like a familiar boutique oil, maybe not suitable for break in. Ask them what oil they used.

 

[csandste]

I'm no expert but the metals don't look that bad. That's why they call it BREAKING in. Hopefully you'll get more expertise in future posts.

 

[dave1251]

Originally Posted by csandste
I'm no expert but the metals don't look that bad. That's why they call it BREAKING in. Hopefully you'll get more expertise in future posts.



I'm concerned about the lead but not enough data to say for certain.

 

[dnewton3]

Tomato -

Please update us with the engine series info, lube info, miles etc.
It will help understand the conditions of the UOA.
and then i will also update the thread title; we like to see the engine description, oil grade and brand, miles on oil and vehicle ...

At the top of this sub-forum is a "how to post" sticky thread.

 

[DuckRyder]

1996 BMW B25 should be M50-B25. 2.5L DOHC inline six. Used in multiple BMW models.

 

[andyd]

Please post a follow up. Not familiar with the M50, the M20 and M30s rarely needed rebuildng. How many miles are on the run in? TIA

 

[FlyNavyP3]

With the described behavior, and elevated iron, copper, and lead I'd be concerned but not in a panic, yet. I'd make sure you're covered liability wise for tuning if the customer chooses to continue. My gut feeling is that this new rebuild is going South and additional dyno pulls or street driving will bear that out. My personal suspicion is that it has a bearing issue, it's shedding a LOT more lead and copper than I'd be comfortable with even given it's low mileage/time.

 

[addyguy]

Those are not 'break in' metal levels. Those are 'engine is broken' metal levels.

 

[MolaKule]

Originally Posted by Kestas
Please update us with the engine series info, lube info, miles etc.
It will help understand the conditions of the UOA.
and then i will also update the thread title; we like to see the engine description, oil grade and brand, miles on oil and vehicle ...

At the top of this sub-forum is a "how to post" sticky thread.



It appears the oil is a 40 grade, maybe a XW40? What grade of oil is speced for this engine?

I assume you have no idea how they rebuilt it, such as, did they put any assembly lube on the cams, etc?

Rebuilt engines are always tight but even a rebuilt engine should start fairly easily. I would have them drop the pan and look at at least one bearing.

This reborn engine has some problems.

 

[claluja]

High metal numbers look problematic IMHO. Be careful - don't get blamed for this for tuning it.

 

[tiger862]

That engine doesn't seem put together by a knowledgeable BMW technician. Looks like bearing clearances are tight and the way you describe it doing seems like valves are out of adjustment.

 

[tomato]

Ok, the oil was 20w50 gtx and has a bottle of restorer in it.

Thanks for the comments!