E34 M5 "ENGINE OIL PRESSURE, OWNERS MAUNAL" Warning Light! Help!

[M3NACEe46]

I just picked up an e34 m5, of the many thing that need doing number one is finding and stopping an oil leak.

I chased it down to where the oil filter housing mounts to the block. I purchased the gasket and installed. In the process I disconnected the oil cooler lines (re-connected w/ new o rings), installed new PS belt, other two looked newish, cleaned throttle bodies (inside w/ TB cleaner and out) new vac lines (all). Cleaned the oil filter housing w/ brake cleaner. Tried not to get any directly into the canister but I’m sure some made it in. The housing sat outside of the car for a few days. After a week of so I finally got her back together. Filled her up with Castrol TWS 10w60 (heard a lot of people choose to run this oil, P.O. did as well, I have a case left over from my e46 m3) 5.5 liters, figured there was still about 0.25 L still hanging around in the engine and would top it off if needed. Cold oil level measures at max line. Too much oil? I’m to afraid to run it up to temp and check the level. I used red rtv on oil filter housing gasket and only around the perimeter of the gasket, not the whole foot print of the gasket. Small bead 1/16th dia. (no no?) Just opened up the oil filter housing. Filter is coated, but I also put a little less than half a liter in the housing and around the filter when filling.

After putting her back together I ran her up the block and turned around immediately due to the warning light. I would imagine the pressure would be quick to build up? Since all the work and the light being on I have had it running for a total of maybe 5-10 mins. 3 or 4 mins up the block and back. Moved the car a spot over in the garage and again for getting a video.


Would the oil cooler being drained cause this warning light? It probably won’t even be opened until next summer. The oil cooler is only used/ opens when the oil is hot enough right?
How can I check to see if it’s just the oil pressure sensor? (aside from buying a new one and installing) I disconnected the wire/ connector when removing the housing. It’s reconnected now. But it could have easily been damaged while working on it. No visible damage but seems like everything I look at on this 25 year car disintegrates.

The top end is noisy and sounds dry. How can I test the pump? Is there anyway to do so without running the engine? I really do not want to run the engine anymore.

Any good shops recommended here in Denver, CO (that where I and the car is located)?

Any thoughts suggestion would be a huge help!

[M3NACEe46]

Update:

I’m a moron.... changed plugs along with the above and the ignition wire to cylinder 3 was not connect/ seated all the way... brand new oil now smells like fuel.

1. Change this oil right away? Or is it okay?
2. Would this be the cause of my engine oil pressure light?

Please feel free to call me a dumb a$$ in your reply

[ross1]

Paragraphs, please!
Pressure ought to rise in moments, you shouldn't run it at all with that warning, especially under the load of driving. Play with fire at your own peril, that engine will cost a whole lot more to repair than a run of the mill M30.

RTV around the oiling system isn't usually a good idea, a piece coming off can block passages or hold a relief valve open. Maybe not your issue but worth mentioning.

Fuel dilution after running only a short time shouldn't be the issue but yes, change the oil if it smells of fuel.

A mechanical gauge can confirm what you already know, "top end sounds dry". Having the sensor fail concurrent with your work would be a bit remarkable.
If pressure was fine before your work then you know where to start looking.

[93FIM5]

Update:

I’m a moron.... changed plugs along with the above and the ignition wire to cylinder 3 was not connect/ seated all the way... brand new oil now smells like fuel.

1. Change this oil right away? Or is it okay?
2. Would this be the cause of my engine oil pressure light?

Please feel free to call me a dumb a$$ in your reply

Ross has covered most everything but I’m local and if you need anything let me know.

-Greg


Sent from my iPhone using Tapatalk

[NikosX]

Update:

I’m a moron.... changed plugs along with the above and the ignition wire to cylinder 3 was not connect/ seated all the way... brand new oil now smells like fuel.

1. Change this oil right away? Or is it okay?
2. Would this be the cause of my engine oil pressure light?

Please feel free to call me a dumb a$$ in your reply

It's possible your oil pump isn't priming...if it was dry for too long the relief valve can get stuck open and prevent it priming. Years ago I had a similar issue. I ended up replacing the oil pump.

My issue was not the sensor unfortunately.

Do not run the car like this. It takes seconds of s38 low oil pressure to blow a good sized hole in your 401k.

93FIM5 is an amazing resource in your backyard.

Sent from my iPhone using Tapatalk

[NikosX]

Any updates OP?


Sent from my iPhone using Tapatalk

[kouks]

Oil pump is the issue, you did something wrong when re-installing it.

I had a similar issue on my M50 engine, turned out the pick up line came loose, which may be your problem. The s38 has the same oil pump system.

STOP running the car, open up the pan again, inspect the pump and oil pickup line, make sure all are torqued correctly. If that fixes it, run clean oil in the engine for less than 500 miles. The engine running without oil pressure has definitely worn your bearings some, and the residue is in the engine. Replace with new filter and oil within 500 miles. Running 10w-60 is good, but I use LUCAS Oil Conditioner and 10w-40 synthetic. Also, 10w-60 in Denver is molasses in the winter, run basic 10w-40 or less in the winter, switch to the heavy stuff in the summer.

[M3NACEe46]

Thank you all for the responses, always appreciated. Sorry I went dark here. Busy with my 2yr old son, pregnant wife (since posting), work, etc. etc.

Update or lack there of;

The problem still stands, unfortunately I have not made any progress. I made a list of what I did to the car to pass along to a local mechanic so he might be able to help track down where I went wrong.

FYI- This issue was not present when I first got the car in November. So it is definitely something I did. As mentioned above I started chasing an oil leak and below are the steps I went through while "repairing" the oil leak. Which I'm pretty sure was a PS leak all along... sigh

Items underlined and in italics are what I suspect went wrong.

· When I bought the car in November the purchasing agent mentioned it leaks oil and once he got it back to his shop the car was 2 qrts low. So I knew it was leaking from the start. He did not mention anything about the power steering. The car still has the SLS and I have since discovered it is the high pressure hose from the PS pump to gear box that leaks.
- Changed the air filter and cleaned the MAF w/ MAF cleaner. Re-installed/ car drove fine, no warning light.
· Car leaked enough to get warning oil light when it arrived at my house
· In effort to find the leak I removed the Air Box again and pin pointed the leak to right under the oil filter housing. Block, motor mount bracket, motor mount, etc. was wet w/ what appeared to be oil. Oil on oil pan directly under oil filter housing and on the back of the block right above oil pan. Figured the oil worked its way back from housing leak. But there is potentially more engine oil leak spots. (again I am thinking this was the PS leak)
· Set about getting housing leak repaired, ordered gasket from BMW
· Got car on jack stands and drained oil.
· Started with removing oil cooler lines, order new oil cooler line gaskets
· With cooler lines out of the way I still did not have clear access to housing bolts
· Removed Air Plenum box, vac lines, oil separator lines, various hoses etc.
· In process cleaned plenum, removed oil separator from plenum. Clean oil separator w/ break cleaner (surprising amount of oil/ gunk in oil separator)
· Installed new o ring on oil separator, new o rings for trumpets
· Bought and installed new vac lines
· Removed all fan belts (in process stripped tension bar, for both PS and Alt) Ordered new bracket and castle nuts
· Removed alternator, ring terminal on D+ wire broke off during removal
· Unbolted various other items on that side of the block (did not disconnect) to gain access to oil filter housing.
· Disconnected oil pressure switch and oil temp switch from oil filter housing (elec connectors only sensors stayed on the housing)
· Unbolted oil filter housing from car
· Cleaned outside of oil filter housing w/ break cleaner, let dry for a day or two
· Cleaned mating surface of oil filter housing to block w/ break cleaner. Sprayed cleaner on blue shop towels. Some of the towel frayed from break cleaner while cleaning the mating surface on the block and got into holes where housing sits. I feel like I got all of the small bits of towel out… this could be clogging the oil pump?
· Installed oil filter housing w/ gasket. Used RTV on perimeter of gasket, 1/16” bead. Maybe some of the RTV got back into the pan/ pump?
· Torqued top two and bottom left bolts to spec. Could not get socket on bottom right bolt. Torqued by feel
· Installed air plenum. Connected all vac lines, hoses, sensors, etc. Pretty sure it is all routed correctly. I double check everything. But I am now questioning everything I did.
· Repaired alternator wire with new ring terminal, heat shrink. Connection is probably poor. (Battery is dead/ car will not start) more on this below.
· Installed alternator w/ new tensioner bracket, power steering bracket and new PS belt. I ordered all three belts but alternator and main fan belt arrived wrong size. Installed the two belts that had come off the car. I tightened all belts to about ¼” of play, I do not have a belt tensioner.
· Installed new spark plugs.
· Noticed pulse generator/ cam position sensor attached to ignition wire 6 was broken. Snapped off from old age. Ordered new ignition wires ($500 from BMW!)
· Removed valve cover. Noticed several studs where cover bolts attached were over tightened at some point and streched. Ordered and installed new. 5 total. Did not use Loctite or anything for studs, just doubled nutted studs and tightened till they bottomed out.
· Installed new gaskets, all three over plugs and valve cover gasket.
· Re installed valve cover. Tightened all bolts to 10 nm/ inch lb. equivalent. In “star” pattern center out.
· Installed new ignition wires. Wire to cylinder 3 was not seated all the way. Found out after I had put everything back together and drove the car up the block and moved it from one space to another in my garage. Total run/ drive time after all the “repairs” was less than 10 mins.
· Installed new oil filter. Filled engine with oil (Castrol TWS 10w-60). I put half a liter in oil filter housing. 5.5 liters in engine total. From what I could tell the car takes 5.75 liters. (my owners' manual is in French) Figured there was 0.25 L left in the engine and would fill as needed.
· Re-installed fan and fan shroud.
· Re-installed Air box
· Started and drove the car up the block. Got “Engine Oil Pressure- Owner’s Manual” warning light within a few seconds of starting car. Thought maybe the new oil would take a minute to reach all parts of the engine and light would go out after a min or two of driving. Drove up the block. Light still on. Turned corner and stopped. Shut off car. Waited a min or two. Started car again and turned around, oil light back on. Looked for oil spots under where I had been sitting before I turned around. Took car back home to garage. (Engine running less than 5-6 mins)
· Next day clean up garage/ put all the tools away. Moved car over a spot so wife could park in the garage again. (Engine running less than 3-4 mins)
· Started car to capture video and sent it to buyer in Canada and spoke with him on the phone about the problem. He felt top end was dry and do not run the car anymore. (at that point I didn't know spark plug wire 3 was disconnected) Would explain rough idle. (Engine ran for a 1 min)
· Next day- Removed Air box to get a better look at the area I worked on. All wires, hoses, etc. appeared to be connected correctly.
· Opened oil filter housing to check to see if filter was coated with oil. Yes it was but oil smells like fuel.
· Checked ignition wires, found cylinder 3 wire was not seated all the way onto spark plug. Re-seated and checked all others. Did not remove wires or plugs at that time just made sure they were on in the correct order and all seated/ connected to distributor and spark plugs.
· Got car back together and figured I’d run it one last time for a min. to see if I could clear cylinder 3 of fuel etc. Car wouldn’t start. Barely turned over. Checked battery, got 12.08 volts off battery. Fear this may be dead and or related to poor connection from D+ alternator wire to ring terminal.

*Since making the above list, and seeing everyone's posts I have done the following*

- purchase new battery. Did not connect. I suspect a battery drain/ missing ground/ I have no clue. But I'll save that for after I get the oil pressure issue resolved.
- Install new oil pressure switch
- Installed new battery
- Started car to test to see if it was the pressure switch (engine ran less than 1 min)
- Still getting engine oil pressure light
- Re-torqued oil pan bolts to 10nm and oil level sensor bolts
- Spoke with a local mechanic/ s38 guy. Discussed the above list. I want to get the car into his shop but he doesn't seem interested? He is a one man shop ran out of his home garage. He probably doesn't want a basket case e34 m5 clogging up his shop. He was recommend to me by fellow enthusiast If you follow BaT he sells a lot of BMW's on there. He's the airplane hangar guy. This mechanic was/ is currently working on a another s38 rebuild. I'd like him to do the work but I may have to go else where.
- The mechanic suggested I try replacing the oil with Bradpenn (now PennGrade) 20w-50 and he thought that maybe, just maybe, the lower weight oil was to blame for the warning light.
- Order new oil
- Replaced 10w-60 with 20w-50 today.
- Started car again/ still got oil light. sigh... I didn't think this would fix the issue but wasting $80 worth of oil was worth potentially saving over 1k for the oil pump replacement. (ran engine less than a min)
- Ordered a new oil pump. I ordered one from eEuro parts for $480. Which I was pleased with because everywhere else is asking 650 plus. Schiedmann was a close second at 650 w/o shipping from Denmark. ESC, FCP, and BMW Northwest was at 680... My local BMW quoted 730.
- While under the car today I notice a good size oil leak from the rear of the engine. Dripping where the trans and engine block meet. I looked from above and below and couldn't locate the source. After a quick internet search it points to the head gasket (FML), rear head cover/ gasket (FML), or oil return pipe o-ring & gasket. All of which would be $10 in parts and thousands in labor
- Would these be causing the light? I don't think so because these were present when I bought the car and I didn't have the warning light till I did all of the above.




It's possible your oil pump isn't priming...if it was dry for too long the relief valve can get stuck open and prevent it priming. Years ago I had a similar issue. I ended up replacing the oil pump.

My issue was not the sensor unfortunately.

Do not run the car like this. It takes seconds of s38 low oil pressure to blow a good sized hole in your 401k.

93FIM5 is an amazing resource in your backyard.

Sent from my iPhone using Tapatalk

Thanks, NikosX- I suspect this is the issue. During the first section of "repairs" the engine sat dry for a week plus. So this is defiantly possible. And I can't seem to think what else it could be. I have ran the car for a total of 10-15 mins, bad yes but mostly at idle and mainly to test the various "fixes" I've done so far. Base on my list above do you have any other theories of what it could be? Do you think re-working the vac lines, or valve cover gaskets would have anything to do with it?

I did reach out to 93FIM5 and didn't hear back, no biggie. But I was hoping he would be willing to come check it out or recommend a shop. If you know a good s38 mechanic in the Denver area you can recommend please let me know.

Of course the problem is I can't move the car. So where ever I tow it to and get the repairs done is where it will stay. So I'm looking for someone recommended and honest.


Oil pump is the issue, you did something wrong when re-installing it.

I had a similar issue on my M50 engine, turned out the pick up line came loose, which may be your problem. The s38 has the same oil pump system.

STOP running the car, open up the pan again, inspect the pump and oil pickup line, make sure all are torqued correctly. If that fixes it, run clean oil in the engine for less than 500 miles. The engine running without oil pressure has definitely worn your bearings some, and the residue is in the engine. Replace with new filter and oil within 500 miles. Running 10w-60 is good, but I use LUCAS Oil Conditioner and 10w-40 synthetic. Also, 10w-60 in Denver is molasses in the winter, run basic 10w-40 or less in the winter, switch to the heavy stuff in the summer.

I never had the pan off the car/ touched the oil pump. I only did what was listed above. The car has been in my garage ever since which has stayed between 50-60 degrees all winter. It is insulated. But yes I picked up some 20w-50 as mentioned above.


Thanks for staying with me till now, I am an awful writer I know.

What else in addition to the oil pump and gasket should I have done as a "while your in there" kinda deal? Bearings? Rings? Short of a full on rebuild what would you do in my shoes?

I know I just need to get it into a shop. But I'd like to have an idea of what I am getting myself into so any and all advice is very much appreciated.

[BleedsBlue]

We (AAS) discussed your car, and I thought we had responded! Our apologies if we didn't end up getting a response to you, ignoring you was not our intention!

Unfortunately Greg will be moving soon (still local) and in a less-than-ideal garage situation; the guy I trust with my life and S38 rebuilds has another career, now; and the other well-known area S38 expert, Nick @ MAC Autosport, has left the scene/shop been acquired, etc.

What is your timeline? I'm guessing this is not your primary vehicle, or you would have been forced to be more proactive? Feel free to PM me, or shoot us (another) email, or reply here, and we will see what we can do. Initial evidence does lead me to agree with Nikosx that the pump is at fault, and that seems like a good starting point.

Edit: to be clear, you are aware that the oil pressure light is meant to come on briefly on healthy start-up, in all conditions? It's when the light stays on for longer than about 1-2 seconds that you should worry. And I would never discount the sensor, which is test-able; though that would be quite the coincidence, as Ross noted.

[M3NACEe46]

PM'ed you Brent, thanks!

[yukon101]

If you are still looking for a shop I have a great indy (he used to be a dealer tech for 20 years and his guys have similar experience) I very commonly see M3s, M5s there and a few E24 M6s and the list goes on. He is extremely reasonable. Unfortunately he is in the Parker area but well worth it. The shop is Yanzito imports.

I personally do all the work on the E32 but when I cant figure things out I go to him and he always has an answer.