Spaniarduk
Member
I am truly shocked at reading this! Potentially a bottom end rebuild every 30,000 miles?? At at least £2K parts and labour?!? This is enough to put a petrol head like me off the S54 engine!! :-o :-o
S54 rod bearing
- Thread starter Vanne
- Start date
Spaniarduk said:
There's cars out there that have done 100k plus on the original bearings and have been fine.
The issue with buying a second+ hand car is you never know exactly how the previous owner(s) have treated it.
Personally I'd be looking to change them around 80k and I believe the cost is more like £1k than £2k.
Show me 1 set of bearings that has done that mileage and hasnt got the telltale wearspots in it and I believe you....LostBoy_84 said:
That an engine is running doesnt mean its fine. Once it's seizing you can buy a new engine if you're unlucky, so there is no real option to wait until the problem emerges. You cant say 'lets wait until it starts and then quickly change the bearings', by then its way to late.
Look at this like a cambelt. Many cars will run far longer after its recommended change (might even do twice or 3 times as long), but the potential risk of breaking will be very costly.
Spaniarduk
Member
I just quickly though... If the 6 pairs of rod bearings need replacing one would asume that the 4 pairs of crankshaft bearings would need replacing, too??
Is this kind of job something that can be done with the engine 'in situ', or is this and 'engine out' kind of job??
Is this kind of job something that can be done with the engine 'in situ', or is this and 'engine out' kind of job??
GuidoK said:
What intervals would you suggest changing them at?
I have done about 7/8 S54 rod bearing changes,from preventative to ones that have spun and damaged the crank.
I have only fitted OEM bearings although there is plenty of aftermarket options now.
Without exception all the bearing i have removed have had signs of wear,from as low as 38k (thats the lowest i have had one in pieces).Although the M3 i did had 99k on and had destroyed the crank,resulting in a second hand engine.
You pays ya money and takes your choice.
I think BMWZ4MC has the right idea,50k swap should always see you without a failure...
Cost is around £950-£1100
I have only fitted OEM bearings although there is plenty of aftermarket options now.
Without exception all the bearing i have removed have had signs of wear,from as low as 38k (thats the lowest i have had one in pieces).Although the M3 i did had 99k on and had destroyed the crank,resulting in a second hand engine.
You pays ya money and takes your choice.
I think BMWZ4MC has the right idea,50k swap should always see you without a failure...
Cost is around £950-£1100
LostBoy_84 said:
Most specialists in Germany advise every 80k km, so thats every 50k miles. Especially when you drive it different at times other than the normal traffic flow. If you never rev past 4krpm you probably will be fine but who buys an m for that?
The best bearingshellls I've ever seen at a higher mileage change were these, done at 140k km (85k miles) and those were from an elderly gentleman that probably drives like it. And still you can see damage in 1 set. These are from an s50b32 engine btw but those have virtually the same parts (actually bearings and crank are stronger in a s50):
It takes of course only 1 bearing to spin to get yourself potentially a new crank or if the conrod breaks (seen that too) a new engine..
I'm on 45k now, maybe I should get them changed soon?
Liverpool
I've had the service indicator reprogrammed to half the usual intervals. My car sees a lot of track use and spirited country lane driving mixed with stationary London traffic, meaning my long term average fuel economy is in the mid teens. As such, I change the oil extremely frequently. I suspect that's why my shells were fine at 50k.
Glad this thread is helping out lots of people. Good stuff. 
Also along the lines of bearings, please please pay close attention to your chain guide.. my top part of the chain guide had virtually ground down, missing about 4cm from the end...
I'll post pics if required, but I am sure you will get the jist.
Remember... Chainguide!!! <---- cheap as chips, exy if it goes..
this pic is added to show a new S54 Chainguide, see how much is missing.
Also along the lines of bearings, please please pay close attention to your chain guide.. my top part of the chain guide had virtually ground down, missing about 4cm from the end...
I'll post pics if required, but I am sure you will get the jist.
Remember... Chainguide!!! <---- cheap as chips, exy if it goes..
this pic is added to show a new S54 Chainguide, see how much is missing.
Geeeez I think I'll just keep mine in the garage.........what with Big ends, Cam sprocket bolts, Vanos oil pump drives and now tensioners it seems like the S54 is a ticking time bomb !!!! Mine has 53K on the clock now so my dilemma is where do I look first top end or bottom what is going to go first. !!! :wink: