Blown motors, Rod Bearing failure S65 Registry.

VCMpower wrote  

Thanks. I do know of a LC motor that has been set to .002 and those are real specs I gave you. So you have a little more info if you wish to take it. It does not reach above 60 psi at that clearance. This is why I was curious if you were thinking a dry sump setup where you can achive different pressure/flow. Taking another S65 apart on Monday so I will let ya know what clearances are there and condition of bearings. It is a 2008. That is quite amazing if that is all Dinan is doing and maintaing pressure. If I remember correct BMW provided thinner shells for the S54 and a larger volume oil pump.

BMRLVR wrote

Generally speaking, oil clearance does drop as oil clearance increases hence that is the reason why engines lose oil pressure if main and/or rod bearings are worn excessively.

20-25 PSI is lots of oil pressure at idle (40 PSI actually a fairly high number at idle) if that is even the number that the S65 engine would have at .002". I have never seen anyone test the oil pressure on an S65 with .002" main bearing clearance but would look forward to the numbers. As for your maximum pressure, that is going to be set by the system relief valve......... if the relief is at 80 PSI, once the pump makes enough flow to go over relief it will still achieve that same 80 PSI that you state, it may just take a few more RPM to get there........ the principles of hydraulics are universal pressure is the resistance to flow and more flow equals more pressure. Flow increases as the oil pump RPM increases(oil pump speed is tied directly to engine RPM) which is why there has to be a system relief to protect the system from overpressure since the oiling system on the S65 uses a positive displacement pump.

FYI: Dinan sets the main bearings to .0019" and the rods to .0025" on their strokers....... I obtained this information while shopping for a stroker! Obviously they see an issue with the tight OEM clearances and they don't see an oil pressure issue with adding a bit of clearance to the Mains and Rods since they use an OEM oil pump!

e92zero wrote

I sometimes wonder if the BMW engine was really designed with a thinner grade oil from the start with the tight tolerance that BMRLVR pointed out. Then another BMW department decided to market and use the 10-60w for the prolonged 15k oil change interval. Would really like to know about the use of thinner oil, especially for some of us that change the oil at 5k or 7.5k.

Radiation Joe wrote  

e92zero wrote

I sometimes wonder if the BMW engine was really designed with a thinner grade oil from the start with the tight tolerance that BMRLVR pointed out. Then another BMW department decided to market and use the 10-60w for the prolonged 15k oil change interval. Would really like to know about the use of thinner oil, especially for some of us that change the oil at 5k or 7.5k.

Take a look here.

I've run a mixture of 5W-30 Redline mixed 50/50 with Redline 40W race oil for the last two runs in my car. The current fill is 10W-40 mixed with the 40W. I want to get in some track time and see how the used oil analysis (UOL) comes back.

Radiation Joe wrote

Take a look here.

I've run a mixture of 5W-30 Redline mixed 50/50 with Redline 40W race oil for the last two runs in my car. The current fill is 10W-40 mixed with the 40W. I want to get in some track time and see how the used oil analysis (UOL) comes back.

VCMpower wrote

Great info. Look forward to the results on the thinner mix.

BMRLVR wrote  

Radiation Joe wrote

Take a look here.

I've run a mixture of 5W-30 Redline mixed 50/50 with Redline 40W race oil for the last two runs in my car. The current fill is 10W-40 mixed with the 40W. I want to get in some track time and see how the used oil analysis (UOL) comes back.

VCMpower wrote

Great info. Look forward to the results on the thinner mix.

I am not at all surprised with these results and I am tempted to start using 0w40 or 5w40 for my next oil change!

If you look at Joe's UOA reports, he is one of the few people who have no lead in his samples.......... I will definitely be sampling my car on the next oil change and may change out to a something in a 40WT and then sample that!

BMRLVR wrote

I have pointed out what I think is the issue with the S65 "bearings" in a few threads now, but unfortunately someone at M3 post deleted posts as the discussions continued.

There is no major bearing issue with the S65. What the S65 has is oil clearances on the Main and Rod bearings that are in my opinion way too tight. For most engines there will most likely never be an issue, but, with clearances of around 0.001 there is not much room for error on assembly/during machining of the main bearing bores in the block. Basically what I am saying is that on an engine where the alignment of the main bearing bores is out even slightly or a rod has a big end that is even minutely oval shaped (either from manufacturing or by being stretched from an over-rev), there is no room for error at all. If the engine had say 0.002 which is a number that I feel should be a minimum, or even 0.0025 which the number I would like to see (TWS 10W60 is ideal to take advantage of this larger clearance since the viscosity of 60 at operating temp would lend you to believe it could handle a large oil clearance and oil pressure should not suffer) issues with the S65 main and rod "bearings" would be non existent.

So to all of you folks that think that the S65 has a rod bearing issue, that is not in any way shape of form the case, the S65 has a oil clearance issue and unless that is addressed no bearing you put into this engine will solve the problem unless the machine work is done to set the clearances to an acceptable number!

BMRLVR wrote

Generally speaking, oil pressure does drop as oil clearance increases hence the reason why engines lose oil pressure if main and/or rod bearings are worn excessively.

20-25 PSI is lots of oil pressure at idle (40 PSI actually a fairly high number at idle) if that is even the number that the S65 engine would have at .002". I have never seen anyone test the oil pressure on an S65 with .002" main bearing clearance but would look forward to the numbers. As for your maximum pressure, that is going to be set by the system relief valve......... if the relief is at 80 PSI, once the pump makes enough flow to go over relief it will still achieve that same 80 PSI that you state, it may just take a few more RPM to get there........ the principles of hydraulics are universal pressure is the resistance to flow and more flow equals more pressure. Flow increases as the oil pump RPM increases(oil pump speed is tied directly to engine RPM) which is why there has to be a system relief to protect the system from overpressure since the oiling system on the S65 uses a positive displacement pump.

FYI: Dinan sets the main bearings to .0019" and the rods to .0025" on their strokers....... I obtained this information while shopping for a stroker! Obviously they see an issue with the tight OEM clearances and they don't see an oil pressure issue with adding a bit of clearance to the Mains and Rods since they use an OEM oil pump!

e90m3_6MT wrote

I wonder if the broken rod could have something to do with a bearing issue?

magicknife wrote

Hello there I have an e92M3 ie until last Saturday. Initially started off as a light ticking sound at3000 rpm, got louder gradually, so loud that when I phoned BMW emergency service, the could hear it over the phone.

Lucky I have BMW extended warranty I got a courtesy car. As it was over a sat, the BMW technician came over, listened to the sound and said it needs a new engine. So lets see what BMW say. Will keep you posted.
Cheers people

s65e90 wrote

What baffles me (as it seems so simple) is why use such a thick oil on a car w/ such tight tolerances. a thinnner oil would seem to be able to have much better lubrication. But I know that the 10 60 is designed to take a beating; maybe we just don't drive these cars hard enough

s65e90 wrote

What baffles me (as it seems so simple) is why use such a thick oil on a car w/ such tight tolerances. a thinnner oil would seem to be able to have much better lubrication. But I know that the 10 60 is designed to take a beating; maybe we just don't drive these cars hard enough

M3NST3R wrote  

The same just happened to me. Im glad this thread is here so BMW service cant act like this only happened to me. I have a babied 47k miles 2008 bmw m3 and this just happened. they are asking me to pay 26K +++ for a new engine. I will be showing this to my lawyer and work on getting them to cover it. I complained of engine noise so many times throughout the 4 years of warranty and they always came back with no problems with the car. i even had them do a final service before the warranty and yet again no one picked up anything supposedly. Its messed up between myself and my family we have owned over a dozen bmw's and they better make it right.

I'll post it with a video tomorrow and ad it to here for others who get told they need to pay 26k to get their car back after spending a lot on this car and taking care of it like a baby for the last 4 years. No engine mods, never raced, only put 4k miles in the last 12 months.

As soon as warranty expires. 2k miles later then engine blows for no reason.