Seeking Advice/Help - Red Oil Light Flicker

[wiliulfo]

Good evening all,

I bought a 2003 E85 roadster last October that had 120k miles at the time.

Drove it from the PO's home in Las Vegas to my home in So. Cal with no issues. After running an OBD II scan, I found several fault codes which led me to replace a couple things. I also got the oil changed at a Valvoline Quick Stop shortly after the purchase.

Most recently, I replaced the thermostat and coolant about two months ago and then the battery at about the same time...

That's when my problem started...

While driving the car about 20 miles to a body shop last month (outside temp was probably mid-90's), the RED oil light started to flicker after getting off the freeway and coming to a stop. When I got the car moving again, the oil light turned off...

Ever since then, the RED oil light will flicker at a standstill at about 700 RPMs. This includes times when I've just cruised around my neighborhood in the evenings for about 20 minutes at a time (that is, in cool weather, with the car warmed up, and never going above 40 mph).


After trying to research the possible issue(s) with the M54 engine, it appears that there aren't many definitive answers about the RED light flicker...

Some say the sensors may be bad; other comments suggest a failed or failing oil pump.

I'm keeping my fingers crossed that it is the easier/cheaper fix of sensors as opposed to the labor-intensive oil pump problem.

Presently, I've purchased the oil level sensor, the two sensors that are near the oil filter, and a DIY oil change kit with BMW oil from ECS tuning.

Before doing this job (replacing 3 sensors, oil, and filter), I wanted to ask the forum for any thoughts on sensors vs. oil pump, and about anything I should be aware of while doing this job.

Thank you!
~Will

[StickMon]

My money's on a bad sensor. I seem to remember another thread on that.
I think the oil pump will either work fine, or fail catastrophically.
Maybe it was this thread, but it doesn't come to a conclusion.
Maybe Spaceman Spiff has an update.

[conceptautogroupla]

+1 on a failing sensor

[dc_wright]

What weight oil was put in at the Valvoline shop? Could be the sensor or the PO may have been using a heavy weight oil that masked a low oil pressure issue.
Also, what filter did the shop install. There have been some posts on cheap filters collapsing causing a flow restriction.
Assume you've checked the oil level?
This is one of those "don't drive the car until it's fixed" kind of issues. If the oil pressure sensor is good and you truly have low pressure you're damaging the engine.

[wiliulfo]

Not gonna lie, I'm pretty disappointed...

First off, thanks to those who responded to my post; I appreciate the input.

DC - in response to your post, the Valvoline folks used 5w30 and the oil was changed in about December 2016.

I've only put about 2,500 miles on the car in the nine months I've owned it and it seems like the light started flickering only after I replaced the thermostat and battery in May/June 2017.

Fast forward to last weekend when I got the car onto a lift at Your Dream Garage in Baldwin Park, CA. I was able to replace all three sensors (oil temp, oil pressure, and oil level), install a Mann filter, and add about 5.5 quarts of BMW-branded oil.

On the +/- 25 mile drive back home (avg speed 75 mph in 92-degree heat) the car felt great, and when I got off the freeway and came to a stop there was no oil light! When I got home, I even let the car idle at the curb in "D" for several minutes; again no flicker. (Picture #1)

I thought all was right with the world until I next drove the car this evening to grab dinner. About five miles from the house, while taking surface streets and not going above 45 mph, the flicker came back again.

So at this point, I suppose I'll have to take it to a mechanic to get checked out...like you said DC, I don't want to drive it until the issue is identified and addressed.

With that being said...does anyone know what diagnostics might be run or what diagnostic methods might be used? I'd hate to drop a lot of $$$$ for a mis-diagnosis only to have the oil light return...


FINALLY, it seems like it's 1 step forward and 2 steps backward with this car...like I said above, last weekend was the first time I had the car on a lift and the first time I was able to take a look underneath...

Seems like the PO really liked zip-ties and I was wondering if any of you know what was tied off (see pictures 2 and 3 below)?

Also, what exterior trim piece (Part #, maybe?) should go in that gap between the front of the wheel and rear of the bumper? Right now, there's nothing on either side...(picture #3)

- First picture is from last Saturday after getting home. No flicker, oil temp 118-degrees Fahrenheit;
- Second picture is the crap the PO zip-tied together; and
- Third picture is the gap between the front wheel and front bumper which is completely exposed.

[StickMon]

Well, that's definitely the ambient air temp sensor cable tied to the harness.

Looks like you're missing at least the left side part #6 here.

They're commonly damaged by bottoming out.

[dc_wright]

Originally Posted by wiliulfo

Not gonna lie, I'm pretty disappointed...

First off, thanks to those who responded to my post; I appreciate the input.

DC - in response to your post, the Valvoline folks used 5w30 and the oil was changed in about December 2016.

I've only put about 2,500 miles on the car in the nine months I've owned it and it seems like the light started flickering only after I replaced the thermostat and battery in May/June 2017.

Fast forward to last weekend when I got the car onto a lift at Your Dream Garage in Baldwin Park, CA. I was able to replace all three sensors (oil temp, oil pressure, and oil level), install a Mann filter, and add about 5.5 quarts of BMW-branded oil.

On the +/- 25 mile drive back home (avg speed 75 mph in 92-degree heat) the car felt great, and when I got off the freeway and came to a stop there was no oil light! When I got home, I even let the car idle at the curb in "D" for several minutes; again no flicker. (Picture #1)

I thought all was right with the world until I next drove the car this evening to grab dinner. About five miles from the house, while taking surface streets and not going above 45 mph, the flicker came back again.

So at this point, I suppose I'll have to take it to a mechanic to get checked out...like you said DC, I don't want to drive it until the issue is identified and addressed.

With that being said...does anyone know what diagnostics might be run or what diagnostic methods might be used? I'd hate to drop a lot of $$$$ for a mis-diagnosis only to have the oil light return...


FINALLY, it seems like it's 1 step forward and 2 steps backward with this car...like I said above, last weekend was the first time I had the car on a lift and the first time I was able to take a look underneath...

Seems like the PO really liked zip-ties and I was wondering if any of you know what was tied off (see pictures 2 and 3 below)?

Also, what exterior trim piece (Part #, maybe?) should go in that gap between the front of the wheel and rear of the bumper? Right now, there's nothing on either side...(picture #3)

- First picture is from last Saturday after getting home. No flicker, oil temp 118-degrees Fahrenheit;
- Second picture is the crap the PO zip-tied together; and
- Third picture is the gap between the front wheel and front bumper which is completely exposed.

Oil capacity on your M54 engine is 6.9 quarts (6.5 liters) so if you only refilled with 5.5 then you're below minimum. Likely not helping your oil situation. First thing your mechanic should do is connect an external oil pressure gauge and monitor what your actual pressure is reading.

[wiliulfo]

StickMon - Thank you for pointing out the parts I'm missing...too bad they're like $250 each! Well, better start saving...

DC - you're absolutely correct. I had just checked my oil level and added about 1.5 quarts a few hours before your latest response. I still haven't had the chance to drive the car and see what effect, if any, this may have on the oil light issue.


Now, I'm going to sound like a dumb a$$ with this question, but I was wondering if what I inadvertently did several months ago may have affected my current oil pressure situation...

Like I mentioned above, I changed out the thermostat on my own about three months ago. After replacing the part, I took the car for a short test drive around my neighborhood...but the temp gauge quickly moved to red and about 30 seconds later I heard a "pop" come from underneath the hood. I tried as quickly as I could to pull over.

When I checked under the hood, I saw that one of the coolant hoses disconnected from the thermostat; causing the popping sound and causing coolant to splash everywhere.

I reconnected the hose, limped the car back home (about 2 blocks), and thereafter learned about how to "bleed" air out of the cooling system. After bleeding the system (running the AC while adding coolant) everything seemed fine. However, I have read that overheating the aluminum block on the M54 can be fatal at times.

Could this have contributed to my current oil pressure problem? And although slightly off topic, how would I know if I totally screwed up my engine?!?!?!?!

[dc_wright]

Originally Posted by wiliulfo

StickMon - Thank you for pointing out the parts I'm missing...too bad they're like $250 each! Well, better start saving...

DC - you're absolutely correct. I had just checked my oil level and added about 1.5 quarts a few hours before your latest response. I still haven't had the chance to drive the car and see what effect, if any, this may have on the oil light issue.


Now, I'm going to sound like a dumb a$$ with this question, but I was wondering if what I inadvertently did several months ago may have affected my current oil pressure situation...

Like I mentioned above, I changed out the thermostat on my own about three months ago. After replacing the part, I took the car for a short test drive around my neighborhood...but the temp gauge quickly moved to red and about 30 seconds later I heard a "pop" come from underneath the hood. I tried as quickly as I could to pull over.

When I checked under the hood, I saw that one of the coolant hoses disconnected from the thermostat; causing the popping sound and causing coolant to splash everywhere.

I reconnected the hose, limped the car back home (about 2 blocks), and thereafter learned about how to "bleed" air out of the cooling system. After bleeding the system (running the AC while adding coolant) everything seemed fine. However, I have read that overheating the aluminum block on the M54 can be fatal at times.

Could this have contributed to my current oil pressure problem? And although slightly off topic, how would I know if I totally screwed up my engine?!?!?!?!

The aluminum head does seem to make the M5X engines a bit sensitive to overheats, with a blown head gasket being the typical result. A blown HG can compromise the combustion chamber to cooling circuit seal, the cooling circuit to oil circuit seal, or either circuit to the outside world. It's very rare to get an oil circuit to combustion chamber breach, but with this or the cooling circuit to combustion chamber breach, you get copious smoke out the exhaust which you would have likely noticed by now. Oil circuit to cooling circuit breach puts oil in the coolant or coolant in the oil. Coolant in the oil makes it look like chocolate milk. A breach of either to the outside world would have either coolant or oil seeping out at the head to block joint somewhere around its periphery.

[wiliulfo]

Closing the loop (hopefully)...

After doing a lot more research and trying to find some other "cheap" fixes (as opposed to dropping the oil pan, changing the head gasket, etc.), I stumbled across a post on another forum which I looked to for a possible fix (I couldn't find the link to include it here, unfortunately) .

I am not too mechanically inclined, but the poster's theory seemed plausible: According to him, he was experiencing the red oil light flicker because his engine running too hot, thus causing the the 5w30 oil to thin out. And since the oil pressure is lowest while sitting in "D" at idle, the hot, thin oil caused a drop in pressure, and thus caused the light to flicker.

As I mentioned above, I replaced the thermostat several months ago...and I guess this is another lesson learned. Because I was impatient, I decided to go down to my local auto part store and get a "house brand" thermostat instead of waiting a week or two for
a Mahle Behr or Wahler from ECS Tuning.

I suspect that upon installation it was either (1) a bad thermostat or (2) I may not have properly tightened the lower hose. In either case, I believe this caused the motor to run hot.

Fast forward to about 2 weeks ago (my car had been pretty much sitting since August): I finally got around to installing a Mahle Behr thermostat I bought from ECS and yesterday I had the chance to take the car out for a spin in "real-world" conditions: I spent about 4 hours on southern California freeways - stop & go, slow speed, freeway speeds, etc.

AND, lo and behold,...(drumroll please)...I am happy to report that she seemed to be running great! With that said, I hope that my Z4 will now transition to my DD as I had intended when I purchased the car last year.

Funny thing is, now that all the "major" issues with this car have been addressed, I am having a bit of anxiety because all the warning lights on the instrument cluster are off and I the gauges look so plain now!! :-)

dc_wright, StickMon, and conceptautogroupla, thanks once again for your input!!

[StickMon]

Good to hear.
That can happen from high engine temp.
My '73 Sports Bug sucked something into the fan intake that was blocking the air flow, and resulted in oil breakdown and the same flickering oil pressure light.