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I am currently in the process of rebuilding my S38B36 after discovering a bad head gasket. Obviously, oil has been drained from the entire system including the oil cooler. I was wondering if anyone could confirm the proper way to prime the entire system in a newly rebuilt engine, and specifically how to ensure there is oil in the oil cooler before the thermostat opens? I'm paranoid about the oil level dropping once the thermostat opens.

I had a bad experience with my 135i getting an additional oil cooler installed, and no additional oil was added to the system. When the thermostat opened at the track, the oil level dropped in the system, destroying my VANOS...

Related: any tips for proper initial break-in when starting her up for the first time?
 

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Please contribute your best information, gentlemen. Bavarianstig truly deserves the very best S38, and I am here, to make that happen. I'm going to pour oil through the cooler and lines, and disconnect fuel until I have oil pressure.

Everything is spanking new, top quality, mainly aiming to stock, but occasionally much better. I sent back the Chinese engine mounts today, accidentally ordered. Conteco on the way.

We have every hose, brand new, every belt, brand new. Michael has even kept the air-pump system, dead stock, with brand new parts. I'd have burned that stuff in a pyre, but let's all pause to admire Michael's dedication of keeping everything pristine stock, or better.
 

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@ bavarianstig,
@ bmwdirtracer

Best thing to do is use Assembly Line Lube when you put the engine together.
Red line or Brad Penn both products are good.
I used both and personally prefer RedLine, BradPen says little bit
when expose to air.....
Yes the classic way is remove the plugs and have the engine turn
by the starer without any build compression, no fuel etc etc etc.....
But the engine is still turning right...

On any engine I put together I use this lube and its the best way of first start.

I never ever use OIL because prior to assembly a little drop will
touch some areas were you use sealant and it will cause a leak in time....
Let's say cam tray, or front timing cover etc..

So my personal way of doing is,
Lube all the moving parts which contact to each other to remove
any premature ware when turn the engine,
This way the other areas will remain dry,
this will help for sealant materials to dry properly while assembling engine parts.

The product/s are thick and tacky and they stick very well and
dont fade at all
You can turn the engine safe while you are dong the timing set up etc..

I have seen many engine builders use Oil and its all over the place...
After first few miles put the engine start establishing a small oil leaks hear and there.

Oil cooler thermostat to open prior to turn the engine ?....Erase this question out of your head.

Hope this helps little bit.

Keeps us update.

Regards
Anri
 

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All bearing surfaces and similar items will of course be coated with assembly lube. I like Permatex Ultra Slick.

I agree that trying to protect the engine by prelubing with ordinary oil is not a good idea; oil doesn't stick well enough, or provide enough protection during the initial critical priming phase. But I will prefill the oil filter housing as well as I can before putting the cap on it, and I will be filling the cooler and lines before connecting them to the filter housing.
 

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Chris,

You are on the right path.

Remember when you turn the engine to do the timing,
also to do shim adjustment we are rotating the engine and this very important for the parts to be lubricated, new rings, pistons, bearings, shim buckets etc.

I see no reason to fill/push the oil cooler lines with oil because you are already using the assembly lube. But if this makes you feel save sure your time your money nothing wrong.

Are you using a brand New Oil pump ?
Or the Existing housing and New gears ?
If yes before you install it deep the gears with oil or poor oil not lube line because the lube line is too think.

Chris remember if you use the lube line prior First engine start,
by the time fuel will gets into the engine you have at least 5-10seconds in cranking...by that time the pump will start filling the galleys with oil slowly.
You can crank the engine without spark plugs and fuel off till you see the oil light off

No need to be that worry, you are using lube assembly and pre filling the oil filter housing with oil.
Plenty enough.

Keep us update.

Regards
Anri
 

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I'm paranoid about the oil level dropping once the thermostat opens.


Regarding the oil thermostat, it probably does not cut off oil flow 100% when closed as this would be problematic for the reasons you state. It most likely allows a small amount of oil flow to bypass into the cooler when the thermostat is closed to keep it primed and to prevent oil level issues. This is the case generally with oil coolers, I can't imagine BMW designing one cutting off flow 100%.


So when you fill the crank case with oil, it will fill the cooler. Now, that wasn't enough for me when I did the first start on my rebuilt Ford 347 stroker (Chris isn't a big fan of Fords, can't blame him really :hihi:). It has an oil cooler with integrated t-stat with about 10% flow bypass when closed. I primed it by pouring oil into it through the inlet hose, the same thing as Chris mentioned.


The first crank I did was w/o plugs and ignition. Once oil pressure was achieved, plugs were installed. The time it took to install the plugs should have been long enough for any air present to purge in the oil system.
 

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Very many thanks, Anri, and deWitt! The valves will be pre-clearanced, stone cold, of course. Michael's car has instant oil pressure, I have no plans to do oil pump. Do you disagree? Yes, I did oil pump on my engine, but it showed a light for a couple of seconds.
 

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i use graphogen, its the best as it doesn't run off the bearings, clylinder walls etc where its applied as its quite thick. Which is good if your slow and built the engine up over weeks not days. Some people don't like it because its black in colour and stains the oil dirty. Its protection is 2nd to none though on initial start up

I just do as Chris says and pull out the fuel pump fuse and crank engine over on the starter until the oil pressure dash light goes out on the clocks. This can often take a while!
 

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I have no plans to do oil pump. Do you disagree? Yes, I did oil pump on my engine, but it showed a light for a couple of seconds.

I agree with your plan re the oil pump. Id check the pressure relief valve for proper functioning, but otherwise a visual inspection in consideration of immediate oil pressure on startup is fine in my opinion.

http://www.realoem.com/bmw/enUS/showparts?id=HD93-USA-05-1990-E34-BMW-M5_36&diagId=11_0503

numbers 8, 9, 10 are what I would replace on the pump, of course a great opportunity to address the tensioner, #16.


It is also important to check the oil filter canister valves for proper functioning as this is important for pressure on startup. If it has immediate pressure on start, then the valves are probably good to go for another engine lifespan.
 

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Oil pump chain tensioner and rail are being replaced. This car shuts off the pressure light 1/4 second before engine start, stone cold. I cannot, therefore, recommend oil pump replacement, with good heart.

I will advise Michael to replace anything that needs replacement....and he will do what needs to be done. We both recognize the need to do what's right.

I don't rely on forums for info....except for this forum. You guys are the very damned best!
 
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