750Li - No oil pressure, plastic bits in oil pan

[dtw]

Hi all - first post in a long time. I am a longtime E39 guy - currently finishing up a 6M swap on an '01 540i Sport. I picked up a 2008 750Li from Copart a couple months ago, more or less an impulse buy. 100K, really clean condition. Light front end hit. I picked up an E65 parts car and swapped out the whole radiator support assembly, bumper, ducts/covers/liners, hood, headlights. Never drove the car other than in the parking lot, but engine ran great.

My paint guy was pulling the car into the shop a couple Saturdays ago. He reported a loud squealing noise on startup from front of engine, followed by a message on the dash regarding low oil pressure/stop engine as soon as possible. Here is what I have found out so far:

-I put a manual pressure tester on the engine, verified 0 oil pressure (fitting wasn't even wet)
-INPA reporting oiling issues at all 4 VANOS units, and 1 tooth off @ bank 2 exhaust cam
-Removed lower pan to inspect oil pump. Screen was clear. While turning crank by hand, it was noted that the oil pump drive shaft is not turning
-Put a boreoscope to the front of the upper pan, and noted chain and sprocket for oil pump drive are in place
-Bottom of oil pan and oil filter housing had quite a lot of plastic bits. Pics are attached.

Working theories:
1. Oil pump sprocket nut backed off
2. Oil pump ingested debris, causing pump to seize and sprocket to spin/gall on shaft.

Right now, number 2 is my favorite theory due to all the plastic bits I found in the pan and filter housing.

Does anyone have any experience with this, and/or recognize the plastic bits?

It is going to be at least a couple weeks before I can move this car to my house and start digging in to the upper pan to learn more. What are some 'while I am in here' things I need to be considering? I already bought the alternator bracket gasket and 6 new check valves. Are chain ramps on issue on these like on the M62?

Pretty nervous about the cam timing. Won't know more until I can check the pistons/valves with a boreoscope. I guess if I bent some valves, that's a good excuse to do the stem seal job.

I'm attaching pics of the contents of the filter housing (orange-glove-clad finger for scale), contents of the oil pan (Torx socket for scale), and just for kicks, a couple shots of the freshly-painted car.

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[jclausen]

I guess remove the lower oil pan for a better look then maybe the upper pan to have a look at the oil pump sprocket nut either way with it having made the noise, I wonder if the engine still turns over.

[dtw]

I guess remove the lower oil pan for a better look then maybe the upper pan to have a look at the oil pump sprocket nut either way with it having made the noise, I wonder if the engine still turns over.

Yes. Lower pan already dropped. I have to finish the interior on my 540i 6-speed project so I can get it out for paint, then I can bring home the 7 and drop the upper pan.

The engine starts and runs. I will not start it again, though, as the top end is out of oil and getting noisy. Plus, I am worried about valve/piston interference due to the bank 2 exhaust cam timing code stored in the DME.

[dtw]

This one seems to have a satisfying ending. After tearing everything down, I found that the oil pump seized up. The drive sprocket galled and spun on the shaft, but no swarf was dropped into the sump. The oil filter was in terrible condition, evidencing a very long filter change interval. The filter media was saturated with debris, and crumbled in my fingers when I pulled it apart to inspect the pleats. Worst one I have ever seen. After removing the valve covers, I noticed that several of the rubber/plastic bolt grommets were missing material from the bottom sections that press into the valve covers. This material seemed to match up with the bits that I found in my sump and oil filter housing. I inspected the chain guides, the oil filter support that threads into the oil pump body, and the relief valve in the oil pump. No other signs of plastic deterioration were noted anywhere else in the engine. I replaced the oil pump with a super-clean, low mile used part from another engine. As cheap insurance – now being thoroughly spooked by plastic deterioration in this engine – I also replaced that oil filter central support. At $20, this gives a lot of peace of mind for what is a critical part of the oiling system.

The DME had reported a 1-tooth variance on bank 2 exhaust cam. I assumed (hoped) this was due to a loss of oil pressure in the chain tensioner, but carefully inspected all the timing parts to be sure. When I pulled the tensioner, I noticed it was completely empty of oil. When I checked the cam timing, all but bank 2 exhaust cam were perfect. The bank 2 exhaust cam was indeed way off. However, when I installed a mechanical tensioner and set enough tension to mimic a properly-functioning hydraulic tensioner, the cam timing was perfect. I rotated the crankshaft several times and re-checked the timing to be sure, and also checked the cam hardware to make sure nothing was loose. On reassembly, one of the very last things I did before starting the engine, was to prime the hydraulic tensioner with oil and install it in the engine. The idea was to try to get the base cam timing as close to optimal as I could on the engine’s first start.

In reviewing the TIS, it seems telling that no mention is made of using a mechanical tensioner when setting the static cam timing. Perhaps this is because the static timing is not as critical, since the engine relies on the VANOS to set the timing dynamically while in operation?

On firing up the engine for the first time, everything checked out and all the codes stayed cleared. I now have 250 miles of normal driving on it, and so far so good. I bought extra oil filters, and will change the filter after 500 miles.

Some notes on the valve cover job:
1. The driver side cover is much easier to install without the dipstick tube and fuel supply line in the way. Don’t be afraid of removing the fuel rail. 2 bolts and some gentle ‘massaging’ to dislodge the injector o-rings, and it is out; it takes 60 seconds. As you remove the rail, check that all the injector o-rings are present. If any stayed behind in the intake, fish them out. On reassembly, carefully clean the injector ports of dust/debris. Replace o-rings as necessary. Be sure all the o-rings are fully seated on the injectors. Lightly lube, and reinstall the rail.

2. The dipstick tube bracket bolt is easy to remove and…not so easy…to reinstall. I found it impossible to install from the engine bay. What worked for me was a 1/4" drive and universal joint and LONG extension, and approaching from underneath the car. Once I got it started, I was able to tighten it down from the engine bay. If you really can’t get it started, it just takes a few minutes to pull the subframe bolts and drop the engine down enough to provide better access.

3. The passenger side cover is much easier to install without the engine hoist bracket and fuel rail in the way. See notes above about the fuel rail. For the hoist bracket, I removed the upper bolt and just loosened the lower bolt. This was enough to let the bracket swing out of the way and greatly eased reinstallation.

4. It is easy to forget about the crankcase pressure relief valves in the valve covers. Be sure to replace them ‘while you are in there’. The delicate rubber diaphragm on mine had failed badly. One interesting note on my car – only the driver side valve cover had one. There was no provision for the valve on the passenger side cover. My car is extremely late production – June 2008. Anyone else seen this?

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