Rod bearings and mounts @115k miles, 15k supercharged

[pokeybritches]

I'm going to be replacing the rod bearings and motor mounts on my M in the next couple of weeks. I will post pictures when she's done. The car has:

-115k miles, mostly highway
-no track time
-regular oil changes at 7500 miles, with two to the full service interval
-a handful of 20 minute canyon runs where the oil temp was elevated
-15k supercharged miles
-raised limiter to 8200 rpm for 40k miles (returned to 8000 rpm with the blower)
-no known engine or VANOS issues
-the car is always allowed 15 min below 4k rpm in order to warm up

This should give everyone a good opportunity to see what the average high mileage, street-driven, supercharged car looks like with the original rod bearings. To be honest, I think the repair is long overdue.

[NickyC]

Nice, even nicer to see a high mileage S54 pushed way past it's original power levels with the same bearings. I just purchased another 2006 M roadster with about 56k miles on it, and I'm kind of kicking around the idea of replacing the bearings myself just for peace of mind. From a casual search around the internet, it would appear that there are many, many S54s with high mileage (120k miles plus) that never had bearing issues. While the motor has had issues in the past, I think a lot of the hype and paranoia is spread on the internet.

[Beedub]

Originally Posted by NickyC

Nice, even nicer to see a high mileage S54 pushed way past it's original power levels with the same bearings. I just purchased another 2006 M roadster with about 56k miles on it, and I'm kind of kicking around the idea of replacing the bearings myself just for peace of mind. From a casual search around the internet, it would appear that there are many, many S54s with high mileage (120k miles plus) that never had bearing issues. While the motor has had issues in the past, I think a lot of the hype and paranoia is spread on the internet.

kinda agree but track work shows to wear them significantly.... I'm guessing a blower and track work like mine will need attention alot earlier. my car may be cleaning looking but that engine has seen some seriously hard use, I've kissed the limiter way more than i care to admit.

[Krypptic]

Originally Posted by Beedub

kinda agree but track work shows to wear them significantly.... I'm guessing a blower and track work like mine will need attention alot earlier. my car may be cleaning looking but that engine has seen some seriously hard use, I've kissed the limiter way more than i care to admit.

Agreed. Mine were just replaced at 60k miles and a handful were showing copper.

[StickMon]

Pokey,
Have you been sending oil to Blackstone?
It would be interesting to compare the Blackstone report to what they look like when removed.
I'm at 107k miles on my stock DD and single digit lead in the oil.

[Shipkiller]

RPM is the main culprit for rod bearing issues. Keep your RPM band 7K and below and your bearings will last longer.

I am also a true believer in a 50W oil over the 60W. I am on my third Blackstone report, with about 15 track days between the last Blackstone report and this latest one and my lead is 7ppm.

[pokeybritches]

Originally Posted by StickMon

Pokey,
Have you been sending oil to Blackstone?
It would be interesting to compare the Blackstone report to what they look like when removed.
I'm at 107k miles on my stock DD and single digit lead in the oil.

I have not, but I should have been doing it. I was under the 100k mile warranty, so I didn't do any for the first few years of ownership. If I were to go back and do it again, I absolutely would take samples. My first sample since going out of warranty was lost due to the shop's owner passing away suddenly, causing the shop to close. I will make sure to take a sample this time!

[pokeybritches]

Originally Posted by Shipkiller

RPM is the main culprit for rod bearing issues. Keep your RPM band 7K and below and your bearings will last longer.

I am also a true believer in a 50W oil over the 60W. I am on my third Blackstone report, with about 15 track days between the last Blackstone report and this latest one and my lead is 7ppm.

I agree about rpm, and for the daily drivers out there - let the car warm up before getting on it!!

Bearing wear seems to be related to track days more than mileage. Really, time spent at high rpm.

[Shipkiller]

Originally Posted by pokeybritches

I agree about rpm, and for the daily drivers out there - let the car warm up before getting on it!!

Bearing wear seems to be related to track days more than mileage. Really, time spent at high rpm.

I never go above 4K rpm until the engine oil temps are at 180' or above.

[tiltmode43]

Looking forward to the results!

[pokeybritches]

I'm finishing up the 3.0i tomorrow. I have to address an issue with the fuel pump first, so this may get pushed a couple more weeks.

On the plus side the bearings, ARP bolts, oil pan gasket, and oil change items all arrived earlier in the week.

[tiltmode43]

Bump!

Ever have a chance to swap them out pokeybritches ?

[pokeybritches]

I have all the parts, and I'm looking at doing a few other things at the same time - a VANOS rebuild, smaller pulley, water/meth, and custom tune. It's been one thing after another though, and I haven't made time to do it yet. I always keep one car in storage in TN, and right now this is the car. I'll update in a few months.

[tiltmode43]

Originally Posted by pokeybritches

I have all the parts, and I'm looking at doing a few other things at the same time - a VANOS rebuild, smaller pulley, water/meth, and custom tune. It's been one thing after another though, and I haven't made time to do it yet. I always keep one car in storage in TN, and right now this is the car. I'll update in a few months.

Sounds good!