Member
I've had a problem with the oil pressure light flickering and staying on at idle.
Problem found: 3 of the 6 oil spray nozzles mounted in the main bearing castings and above the main bearing shells have inoperative check/pressure valves that appear to dump the oil pressure at idle. No other problems found that would cause low oil pressure at idle.
Pictures to follow.
Last edited by tjm3; 04-04-2015 at 05:03 PM.
See ya later,
tony
'98 M3, '92 Dinan3, '05 R1100S BCR, '07 R1200S, Aprilia T
Member
Promised some pics. Here they are.
Again, these are the oil spray nozzles that shoot oil towards the underside of the pistons, cylinder wall and small end of the rods. They're mounted in the block about the upper main bearing shells. They're the first thing to go into the block before the bottom end can be assembled.
First pic. One original bad nozzle and one original good and one new nozzle. You can see the check ball out of position in the bad one.
Second pic. One intact unit and two I cut open, one good, one bad. These things are about 22mm long. You can see the difference between the good and bad unit. The broken spring makes it defective and unable to hold back idle oil pressure.
Third pic. Close up of one broken and one worn spring.
Three of the six in my engine were defective, defective meaning the checkball valve doesn't close when it should. It appears they should open under high pressure and be closed when oil pressure is low (at idle RPM). When they're open they can pass a LOT of fluid.
Here's the deal. There's no mention of these things in the Bentley manual, nothing in any of the factory literature that I have access to or any other database information I've seen. Oil pressure at idle is supposed to be 7 PSI or higher and the oil light pressure switches are calibrated to about that, 7-12 PSI. I pressure tested the valves in the new oil spray nozzles and found they didn't open until the pressure rose above 10-12 PSI. I think this is not just coincidental that the low end of engine oil pressure range and the opening pressure of the spray nozzles are very close. With normally operating spray nozzles the idle oil pressure can stay above the oil light switch pressure, 7 PSI. With one or more defective spray nozzles, a high rate internal oil leak takes place right through these nozzles lowering the oil pressure below the threshold of the oil light switch. Oil pressure comes up quickly as the engine goes off idle as well as when the oil is colder and thicker which is why our oil lights come on mostly at hot idle RPMs. I found no other obvious problems with the oil system and I checked everything.
So what's the point? This. If the engine is apart, change the six oil spray nozzles. Cheap insurance in the long run.
11 42 1 748 199 Oil Spray Nozzle
Last edited by tjm3; 04-12-2015 at 10:17 AM. Reason: added part numbers
See ya later,
tony
'98 M3, '92 Dinan3, '05 R1100S BCR, '07 R1200S, Aprilia T
Member
Great info, thanks for posting this.
shade tree mechanic
Moderator
Thanks, Tony, great info and pics. Please add the part numbers in your post to have it complete. So far no problem on my 98 M3 with this, but ....
Shogun tricks and tips for the E32 series are HERE!
Member
Thanks. Part number added to post.
See ya later,
tony
'98 M3, '92 Dinan3, '05 R1100S BCR, '07 R1200S, Aprilia T
shade tree mechanic
Moderator
Thanks, because I could not find it on realoem, is not shown with a item no. http://realoem.com/bmw/showparts.do?...=103&lang=enUS Oil Spraying Nozzle 6 pcs up to 09/1998 11421748199
Used in many engines:
E34: 525i, 520i, 525ix,
E36: 320i, 325i, 325is, M3, 323i, 328i, 323ti Compact,
E38: 728i
E39: 528i, 520i, 523i,
E46: 320i, 320Ci,
E60: 520i
E85: Z4 2.2i Roadster, Europa
Z3: Z3 M, Z3 2.0, Z3 2.2i
Shogun tricks and tips for the E32 series are HERE!
Member
It should be shown with the lubrication pics but it's a tough one to locate if you don't know where to look. They stuck it on the 'engine block mounting parts' page, Number 14.
Oil Spray Nozzles
Last edited by tjm3; 04-12-2015 at 01:03 PM.
See ya later,
tony
'98 M3, '92 Dinan3, '05 R1100S BCR, '07 R1200S, Aprilia T
Pitbulls Are Not A Crime
Good job locating that. Any idea what causes them to go bad? Not changing oil, sludge, etc..?
If the mind can conceive it, & you believe it, you will achieve it. - Napolean Hill
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Member
No idea why these things go bad considering they're well oiled. At 185K everything was very clean and no sludge.Originally Posted by hide1
See ya later,
tony
'98 M3, '92 Dinan3, '05 R1100S BCR, '07 R1200S, Aprilia T
Member
Sorry to bump a super old post, but I'm curious now that a few more years have passed..has anyone else had this issue? I just purchased a 97 M3/4/5, very well taken care of with about 112k on the engine. The PO went through every possible other issue that could have been on the engine, except for this one. I'm getting an intermittent light at hot idle. I've also noticed that it's more prominent when the nose of the car is facing down hill. Car idles on it's own around 500...if I tap the throttle and bring it up to even 650 or 750... the light goes off. OP, is this what you experienced in your nozzle failure?
Member
No other info on my part. I still get an occasional flicker in a quick stop or when the oil level falls to the lower limit on the stick, even with the supposedly 'better' baffle. Easiest and cheapest way to fix the problem: top off with a quart or so of 10w60 at each oil change.
See ya later,
tony
'98 M3, '92 Dinan3, '05 R1100S BCR, '07 R1200S, Aprilia T
Member
I have this same problem. My car is a 99 with 130k miles.
My symptoms are the same, flickering light when the car is fully hot. Apply any amount of throttle and the light goes out. Oil pressure measured around 4-5psi at idle, builds to 7-10psi when a tiny amount of throttle is applied (and the light turns off at this point) and then pressure builds as normal under full load. Clean oil sample test results from Blackstone, no knocking. No sludge, engine is quite clean.
I have replaced the oil pick up tube, pump, added a baffle to the pan, redone the VANOS, replaced chain tensioners, etc... I am considering replacing the oil filter housing, this was suggested by a mechanic I trust. But I'm realistic that it might not be the culprit and that it's likely my flickering light will persist. These oil squirters are the only thing left I can think of. I'm definitely NOT interested in tearing into my motor at this point though. I think it's one of those things that's annoying but you live with it until the motor comes out for some other reason. I don't see any scenario where I would rebuild a motor just to fix this issue.
Last edited by Nate047; 07-08-2017 at 05:40 PM.
Member
I'm going to assume you've replaced the oil pressure switch with an OEM sensor? I have this issue as well and it continues after replacing the switch. Next I plan to do the oil pick up tube.I have this same problem. My car is a 99 with 130k miles.
My symptoms are the same, flickering light when the car is fully hot. Apply any amount of throttle and the light goes out. Oil pressure measured around 4-5psi at idle, builds to 7-10psi when a tiny amount of throttle is applied (and the light turns off at this point) and then pressure builds as normal under full load. Clean oil sample test results from Blackstone, no knocking. No sludge, engine is quite clean.
I have replaced the oil pick up tube, pump, added a baffle to the pan, redone the VANOS, replaced chain tensioners, etc... I am considering replacing the oil filter housing, this was suggested by a mechanic I trust. But I'm realistic that it might not be the culprit and that it's likely my flickering light will persist. These oil squirters are the only thing left I can think of. I'm definitely NOT interested in tearing into my motor at this point though. I think it's one of those things that's annoying but you live with it until the motor comes out for some other reason. I don't see any scenario where I would rebuild a motor just to fix this issue.
1995 Cosmoschwartz M3/2/5- Daily Driver
1996 Estorilblau M3/2/5- Beater
1998 Cosmoschwartz M3/4/5- Garaged
2003 Sterling Grey M5- "Weekend" Car
Member
Yes sorry, I forgot to list that. the oil pressure sender was the very first thing I replaced because it's easy and cheap.
Apprentice w/#yrs. exp.
Replace o-rings #3,6,7 here:http://www.realoem.com/bmw/enUS/show...diagId=11_1288
Also o-ring #12 here:http://www.realoem.com/bmw/enUS/show...diagId=11_6075
A cheap and easy fix when all other obvious causes have been erased.
Btw,500rpm idle speed is a bit low.
I don't have the actual idle specs, but it does vary between manual and auto transmissions.
Last edited by MIKYZZ4; 07-09-2017 at 01:09 PM.
Member
Can you specify the 3 part #s mentioned here? URL won't open the diagram for me.
I started getting a flicker at idle when hot after car sat for the winter in the body shop.
Thanks.
Apprentice w/#yrs. exp.
Try it now, I fixed the link.
Member
Good suggestion. Maybe I'll do this next time I'm due for a fluid change. I hadn't really thought about replacing the gaskets and o rings instead of the whole housing.
Apprentice w/#yrs. exp.
Those o-rings are known to affect oil pressure on e46,
so I'm assuming it will effect the e36 in a similar way.
Most owners seem to ignore or disregard the condition of those o-rings,
or not even notice that they're missing sometimes, hence the unknown flickering.
I make it a habit to check for brittleness at each oil change.
Member
Good to know! Thank you for the insight.
Member
It worked, thanks a lot!
Member
3/6/7 should be getting changed everytime you change the oil already unless you are buying bare filters somewhere.
Same problem here I replaced the oil pressure switch (only thing I did) and the light went away for several months. It is now back occasionally so I'm gonna try an OEM switch which I should have done in the first place. I am cautious about doing more as seems people have dumped a lot of time/money into this goose chase (post 12) and haven't gotten any closer to solving it.
Member
I noticed something interesting today, decided to experiment a bit. My car is an auto (not for too long) and while taking it for a spin, I put it in manual mode and left it in second gear. I ended up sitting at around 3-4K RPM most of the time and those 6-8 times when I came to a stop, oil pressure light never flickered. Too early to declare a victory, but just something I wanted to share, so FWIW.
Last edited by Mless5; 07-09-2017 at 11:02 PM.
Apprentice w/#yrs. exp.
O-rings won't cost a lot of time or money, but since you change yours every oil change,
have you considered you may have a well worn engine, and need to up your oil viscosity?
Member
My 99M3 owners manual says the oil light may flicker at idle when the motor is hot. You could try a thicker oil. Factory for my 99M3 us 5W30 synthetic. You could try 0W40, 10W40, 15W40, 5W50.
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