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I have a 2003 BMW 325i that the red flashing oil light starts flashing when the engine is idling after about 20 minutes of driving. The light does not flash when starting up the engine but only when the engine is warm (hot oil). I have replaced the oil pressure sender and tried switching to different oil brands and weights but still no fix. I think it has something to do with the cooling system not keeping the oil cool enough therefore it can not maintain pressure at idle.

Submitted: 751 days and 13 hours ago.

Category: BMW

Value: $15

Status: AWAITING CUSTOMER ACTION

Optional Information:
2003 BMW 325i 2.5L

Already Tried:
changed oil pressure sender, changed oil type/weight.

Posted by RIP 751 days and 12 hours ago.

Info Request

Hi, welcome to JA.
How many miles are on this BMW?
~Rip

751 days and 12 hours ago.

Reply

119k.

Accepted Answer

Thanks,
You'll need to take a manual oil pressure test, by removing the oil pressure sensor and installing a tester fuel guage. If the oil pressure drops in relation to when the light was illuminating, than we have an internal engine problem. Either a faulty oil pump, pressure relief valve, or even a partially plugged strainer. If the oil pressure is good, than you most likely have a faiulty Cluster. The Cluster is correctly tested through a factory level scan tool. Let me know if you are taking the oil pressure test yourself and need the specifications.
~Rip

Accepts:
Expert:	RIP
Pos. Feedback:	96.6 %
Answered:	10/31/2007

Lead Technician

BMW Factory Training, ASE Master Techinician, Advanced engine performance.

750 days and 20 hours ago.

Reply

Reply to RIP's Post: Last time my mechanic spent awhile to get to the oil pressure sensor b/c it's in deep. Do you have diagrams or an easier way to reach it? If so I would purchase an oil compression tester to perform the test and need the specs. The other thing is that it only occurs (red flashing light) after the engine has been running at mid-rpms for about 30 minutes so it will be hard for me to duplicate the scenario with the gauge on the engine. Is the oil pressure releif valve easy to replace? Do you recommend using "Motor Flush" for the next oil change or any oil additives to remove clogs? A couple of people I have spoken to says the light is coming on b/c of worn rods & bearings in which I really hope is not the case. I hope to diagnose this on the first try and thanks for your guidance.

Posted by RIP 750 days and 20 hours ago.

Answer

Here's the deal...you need to run the engine under the exact conditions which will cause the oil lamp to illumiante, than you need to install the guage and check the pressure...if the lamp only comes under cruise speeds...than the oil pressure guage needs to be installed while you test drive it. Oil pressure relief valve is part of the pump and is serviced together, and this may end up being a pump problem...which is still going to be a large repair job. Also, I don't recommend any type of flus under these conditions...since you do not know the conditions inside the engine...if there is sludge built up, it will break off in a flush and cuase further oil pressure problems if not imminent engine failure. If the bearings are worn, it would be knocking by now...so they could be scratched from the low oil pressure, but not damaged yet, but the only way to figuer that out is to remove them and inspect...but again, this may not even be an oil pressure concern, so we need to know if the pressure actually drops before speculating anything. Below is the oil pressure specification..
Specifications
Notes Oil Pressure
Oil Pressure at idle speed with engine at operating temp. min bar 0.5
Regulated pressure bar 4.0

Below is the oil pressure switch removal procedure...also be sure the mechanic replaced this switch and not another.
Service and Repair
Notes
Removing And Installing/Replacing Oil Pressure Switch (M54)

Turn off ignition.
Release oil filter cap so that engine oil from oil filter can flow back into oil pan.

Remove intake filter housing.

Installation:
Resecure oil filter cap.
Check engine oil level and top up with engine oil if necessary.

View Full Image

Version 1:
Location: On base of oil-filter.

NOTE: Figure shows power steering pump supply tank removed.

Disconnect plug connection (2).
Unscrew oil pressure switch.
Tightening Torque, 27 Nm

View Full Image

Version 2:
Location: On base of oil-filter.

NOTE: Figure shows power steering pump supply tank removed.

Disconnect plug connection (2).
Unscrew oil pressure switch.
Tightening Torque, 27 Nm

750 days ago.

Reply

One more note is that when I removed the oil cap after the engine runs it is dry. I'm not sure if the oil is suppose to reach it or not.

Posted by RIP 749 days and 22 hours ago.

Answer

It is supposed to be somewhatn wet in there...but this is not a good method of determining if there is oil pressure. If it is getting oil though, pulling the cap on a running enigne should spatter some oil out.
~Rip

747 days and 13 hours ago.

Reply

Is the oil pump electrical or mechanical? I was just curious to see if electrical something was unplugged. Just to be prepared much labor and cost (estimated) is it to remove and replace the oil pump. I did Accept your answer and greatly appreciate your help.

Posted by RIP 747 days and 12 hours ago.

Answer

Thanks for the accept, the oil pump is mechanical, and is accessed from under the oil pan...but the engine timming chain is also partially torn down...I don't want to scare you but the pump and labor can rach up to $1500, depending on the labor rate of the facility, if you have AWD (All Wheel Drive) or not, and is it has one or two timming chains...typically it's around $900. below are all the dealer labor times and part costs.
~Rip
Parts Information
Part OEM Part Price
Oil Pump
Single Timing Chain
Oil Pump
48 - M3 11417836993 $583.00 Notes
Dual Timing Chain
Oil Pump
45 - 325 & 330i, Ci, xi 11417501568 $349.00 Notes

Labor Skill
Level Mfg.
Warranty Standard
Oil Pump
Replace
Single Timing Chain
M3 B 4.5 5.9 Notes
Dual Timing Chain
325
2WD
Convertible B 3.9 5.2 Notes
Coupe, Sedan, Wagon
Manual Trans B 3.9 5.2 Notes
Auto Trans B 4.0 5.2 Notes
AWD
Manual Trans B 6.9 9.8 Notes
Auto Trans B 7.0 9.8 Notes
330
2WD
Convertible B 3.9 5.2 Notes
Coupe, Sedan
Manual Trans B 3.9 5.2 Notes
Auto Trans B 4.0 5.2 Notes
AWD
Manual Trans B 7.0 9.8 Notes
Auto Trans B 7.1 9.8 Notes

716 days and 14 hours ago.

Reply

RIP, To be prepared at the dealer what is the parts & labor cost to replace the lower rods & bearings?

Posted by RIP 716 days and 12 hours ago.

Answer

I really hope it isn't the main and rods, but the labor and parts cost is below. At dealer labor rates i'd estimate the job between $3000-$4000.
Main & Rod Bearings
325
2WD
Convertible, Coupe, Sedan
Manual Trans A 0.0 32.6 Notes
Includes: R&I Engine, Oil Pan & Front Cover And Make All Necessary Adjustments.
Auto Trans A 0.0 33.9 Notes
Includes: R&I Engine, Oil Pan & Front Cover And Make All Necessary Adjustments.
Wagon
Manual Trans A 0.0 32.6 Notes
Includes: R&I Engine, Oil Pan & Front Cover And Make All Necessary Adjustments.
Auto Trans A 0.0 33.9 Notes
Includes: R&I Engine, Oil Pan & Front Cover And Make All Necessary Adjustments.
AWD
Manual Trans A 0.0 37.7 Notes
Includes: R&I Engine, Oil Pan & Front Cover And Make All Necessary Adjustments.
Auto Trans A 0.0 38.9 Notes
Includes: R&I Engine, Oil Pan & Front Cover And Make All Necessary Adjustments.
Parts Information
Part OEM Part Price
Connecting Rod Bearing
Single Timing Chain
Bearings
M3
38 - Upper 11247835440 $14.00 Notes
Includes: One Upper & Lower Shell For One Rod.
38 - Lower 11247835439 $14.00 Notes
Includes: One Upper & Lower Shell For One Rod.
Dual Timing Chain
Bearings
35 - Upper 11241284850 $14.20 Notes
Includes: One Half Shell.
35 - Lower 11241284849 $14.00 Notes
Includes: One Upper & Lower Shell For One Rod.

Posted by MB Guru 715 days and 16 hours ago.

Answer

Rip is pretty much dea on with this one. However, I've had several of the late dual vanos bimmer 6 clyinders that had the wrong weight oil in them. I put the mobil 1 20-50 in them and they were fine. Running the mechanical test is fairly straight up, I took a old sender and made a adaptor for the block that is angled about 30 degrees then by using 1 to 3 alloy crush washers I can get the angle where it does not leak and the nipple is pointing away from all the stuff under the intake.

The ones I've tested had around 9 psi at idle but would bounce badly, the bounce would match the pulse of the LED in the cluster. After changing them to 20-50 they woulstraighten up and have 12~17 psi at idle. Even replacing the pumps and inspecting the main clearances (in spec) did nothing to improve it. Some of these engines just do not like the thinner synthetic oils apparently. I think the issue is more of a leakage problem from the VANOS setup myself. The ones I've swapped over to the 20-50 have been doing fine. One of them is up to 190K now and has been on 20-50 for 65K.

715 days and 12 hours ago.

Reply

With a repair job of 3-4k on a 2003 I probably would not want to keep the car so it's time to make a decision. I have tried Castrol 5-30 and Mobil One 10-30 but not yet the 20-50 weight. Do you recommend oil stabilizers such as Lucas, Duralube, or RESTORE. They are suppose to keep the oil thicker in the same sense as going with the 20-50. I did notice it happening less the second oil change when I used the MANN oil filter. Do you think it has anything to do with the cooling system or oil cooler? I was thinking of purchasing a PEAKE engine scan/reset tool but not sure if it would help in this case.
I will change the oil to 20-50 in a few weeks and let you know.

Posted by MB Guru 715 days and 4 hours ago.

Answer

Well, it would be worth a shot WITH doing the mechanical testing to make sure it actually has oil pressure LOL

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Optional Information

Optional Information: 2003 BMW 325i 2.5LAlready Tried: changed oil pressure sender, changed oil type/weight.

Info Request

Hi, welcome to JA.How many miles are on this BMW?~Rip

Reply

119k.

Accepted Answer

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Answer

Reply

One more note is that when I removed the oil cap after the engine runs it is dry. I'm not sure if the oil is suppose to reach it or not.

Answer

It is supposed to be somewhatn wet in there...but this is not a good method of determining if there is oil pressure. If it is getting oil though, pulling the cap on a running enigne should spatter some oil out.~Rip

Reply

Is the oil pump electrical or mechanical? I was just curious to see if electrical something was unplugged. Just to be prepared much labor and cost (estimated) is it to remove and replace the oil pump. I did Accept your answer and greatly appreciate your help.

Answer

Reply

RIP, To be prepared at the dealer what is the parts & labor cost to replace the lower rods & bearings?

Answer

Answer

Reply

Answer

Well, it would be worth a shot WITH doing the mechanical testing to make sure it actually has oil pressure LOL

Related BMW Questions

Optional Information:
2003 BMW 325i 2.5L

Already Tried:
changed oil pressure sender, changed oil type/weight.

Hi, welcome to JA.
How many miles are on this BMW?
~Rip

It is supposed to be somewhatn wet in there...but this is not a good method of determining if there is oil pressure. If it is getting oil though, pulling the cap on a running enigne should spatter some oil out.
~Rip