Running-In Conundrum

[Sprint'n'Go]

So the tapping could have been related. How do you go from a light tapping for about 80k to a failure in another 150 miles? Does this add up? Especially considering the oil analysis results which indicate a clean bill of health at just before 90k

 

[996jimbo]

So the tapping could have been related. How do you go from a light tapping for about 80k to a failure in another 150 miles? Does this add up? Especially considering the oil analysis results which indicate a clean bill of health at just before 90k

I'd suggest that you would have to know the nature of the con rod failure to answer. But of course the nature of the failure would be your answer.

I would have thought that little end failure would not firstly and only cause a broken con rod. And if the little end was failing then there would have been signs in the oil analysis?

 

[jberks]

My experience is that con rods can go without warning. Certainly there were no unusual noises before it and the piston parted company on my Ford.

I would imagine that, given the stresses involved, any failure would be rapid, so no obvious problems to catastrophic failure in 20 miles or less. True, an aircraft standard examination including xray and you may have found it, but not necessarily from oil analysis as its more likely to have been a stress fracture than a low lubrication/wear issue.

As a partial aside. I have an 18 month old 270CDI. Just clicked past 30k and intending to add at least a 1 in front of that before considering parting company. I insist on Mobil1 at the services and the assyst rolls around every 9.5k.
Now, I have assumed that if anything, this is a premature oil change and Mobil1 should still be very effective at that point. Certainly I saw 17k between changes out of my previous 240. Am I being too generous. Should I swap the oil and filter at 5k?

 

[Blobcat]

As a partial aside. I have an 18 month old 270CDI. Just clicked past 30k and intending to add at least a 1 in front of that before considering parting company. I insist on Mobil1 at the services and the assyst rolls around every 9.5k.
Now, I have assumed that if anything, this is a premature oil change and Mobil1 should still be very effective at that point. Certainly I saw 17k between changes out of my previous 240. Am I being too generous. Should I swap the oil and filter at 5k?

With the amount of miles and type of driving you are doing I think that oil and filter at 5K would be OTT. Even on 13-14K servicing you will get > 1 service p.a.. I try and get around two services per year

 

[OlafMaxwell]

112k, never had to top up between services. First service was about 14k but if I had left it to the ASSYST computer it would have run to about 25k. I know every change has been fully synthetic, still no oil consumption between services. As for running in, the car was just driven normally but no undue engine speeds or heavy loads.