We were driving the 97 M3/4 last weekend in 100 degree weather, and after 30 minutes we would see the oil light (Aladin's Lamp) start to faintly glow when we stopped at a light or sign. I know, an easy solution is to ignore all traffic control devices and keep moving, but with all the CCA stickers on the car I don't want to put the club in a bad light. When we got moving again, the light would fade away, but sure enough at the next stop it would slowly come back again. The temp guage was reading north of average, but not in the danger zone. I checked the fluid levels (all OK) and checked for leaks (only car we own that is not leaking at this point) and I have put a couple hundred miles on it this week, and have not had this happen again. Is this a warning of things to come? Oil pump about to go? Should I change it now? Do I tell Bev it is about to blow up and we need to replace it with an mCoupe? Thanks for your help.
oil pressure light on You need to verify the oil pressure with a direct reading guage with the engine at normal operating temp. and at idle. After you do this, you will be able to diagnose an oil pressure issue or a oil pressure switch issue. Find out what your oil pressure should read at idle and verify the findings. This troubleshooting should lead you in the right direction. Also, in hot weather there is a chance of this happening due to oil viscosity breakdown during extremely hot ambient temp. days. Update us with your findings please. There are also other sights you can post and search for answers like www. bimmerforums.com.
Fairly common. My car does it. Not the oil pump. Certainly not the oil pump nut. I still havent figured it yet out but it could be: wear: (cam journals, main bearings, rod bearings) softened springs in the oil squirters I think it is the oil squirters but in the S52 engine you have to pull the crank to get to them so its basically a. full rebuild to get to a some $5 parts. Use a heavier oil in the summer to alleviate it somewhat.
Thank you for the info. I will dive into this project this coming weekend and let you know how it turns out.
In the owners manual it says that the oil light may light on light upon idle but will go away once you start moving again. Ours did he same thing, had the whole oil system checked out and it was fine, that was before I read that in the manual. wow I feel dumb that was a really old post
Not so dumb a post, I was just starting to read the string today myself. Wd not have thought an oil light wd be expected (and blessed) in the owner's manual.
US m3's should idle at about 9psi hot. I believe the light comes on at 6 or 7psi. I would definitely consider it an issue. I had oil pressure issues in my s50b32, and it turned out to be a combination of a stuck pressure valve in the oil pump and a bad 2nd main bearing. Even Mark Jon Calabrese wrote about my plight in a column last summer! Unfortunately, if the analogue pressure gauge doesn't help much, you'll have to drop the pan and inspect the bottom end. But it is doable, I did all of my work on jack stands. Good luck!
You mean the 2nd rod bearing right? I believe the owners manual states that the oil light may flicker at hot idle, but once the engine begins to wear that becomes a solid light at hot idle.
The reason I asked is because she said she did all her work on jackstands so I was assuming she meant drop the pan and replace the rod bearings.
It is actually possible to roll in mains on these motors if you are clever. Usually worn rod bearings will not cause a critical oil pressure loss, but worn mains definitely will.
No, it was the 2nd main bearing. I replaced all of the connecting rod bearings at the same time, in addition to all new oil pump parts (pump, valve & spring, chain, sprocket & nut). Oh, and on the euro motor the oil pump nut is reverse thread. Hell yes. The mains were tricky tho, but the crank never had to come out. There was a small groove left on the crank from the low oil pressure, but luckily it was minimal and plastigauged (sp?) fine. Car has been stellar ever since (praise the Lord).
I know it is reverse thread. My brother's oil pump nut fell off randomly on his S50B32 and he told me all about it. I don't know if he did any damage, but he did get it fixed up.
I planning to rebuild my S52 in the next year. The main reason is to replace rod and main bearings due to low oil pressure. The head was reworked last year. Is replacing the mains from below a good solution? Would it be better to pull the engine so I can have the crank checked and repalce the rings etc?
I don't know if it would be worth the extra work just to replace rings. You can always use plastigage on the crank to check for wear.
