Bimmerforums - The Ultimate BMW Forum https://www.bimmerforums.com/forum/ Bimmerforums is the preferred online BMW Forum and community for BMW owners. At Bimmerforums, you will find technical how-to information maintenance specifics audio advice wheel and tire combinations and model specific details not found anywhere else. Our professionals are here to help make sure you find the answers you need to your questions and our community is here to help other brainstorm ideas for the future. en Sun, 11 Jan 2026 13:02:25 GMT vBulletin 60 https://forums.bimmerforums.com/images/images/misc/rss.png Bimmerforums - The Ultimate BMW Forum https://www.bimmerforums.com/forum/ Intermittent A/C https://www.bimmerforums.com/forum/showthread.php?2498839-Intermittent-A-C&goto=newpost Sun, 11 Jan 2026 04:07:10 GMT Hello,

I've been stuck trying to diagnose some A/C issues with my 2009 BMW 128i. I notice my A/C fails to cool when the car is idle, likely because the fan doesn't kick on even when I press my A/C button. I've manually turned on the fan via Protools and DME controls, so I know the fan is working -- and it kicks on when the motor temp gets too high I think it triggers at 115-130degC.

I went to a mechanic to fill up the A/C system to the correct levels and even replaced the expansion valve just in case something was going on there. Haven't noticed any leaks and over the course of several months I have no reason to believe there are any leaks since the pressures haven't changed much on the low side (a/c was filled in the summer when temps were close to 40 degC). I have a UV light and have not seen any leaks in the engine bay. Leaks may be hard to spot with the evaporator but I still have refrigerant in the system and the high side holds pressure throughout the months.

Now, I tried to document all my findings today with the following gauge readings:

Outside Temp: 14deg C.

Car turned off gauges connected (no e-fan, no a/c)
Low-65 psi
High-80 psi

Car running (e-fan running, a/c)
Low- 45psi
High- 150-175psi (then fan kicks off and drops down to about 125psi, low side climbs as this happens).

I have also attached a video showing what happens. Would appreciate some insight here, this has stumped me for months.

I don't know if I should consider a new compressor (because it kicks on when I activate my A/c and pressure builds). But something is not allowing my high side to build up pressure past 175psi or so (is this because of a faulty pressure sensor?)

https://youtube.com/shorts/mN7pfRYx7aA?feature=share ]]> General BMW Mechanical Help sponsored by RM European Auto Parts Project 128i https://www.bimmerforums.com/forum/showthread.php?2498839-Intermittent-A-C low cost 4 pin flasher relay https://www.bimmerforums.com/forum/showthread.php?2498838-low-cost-4-pin-flasher-relay&goto=newpost Sun, 11 Jan 2026 01:44:48 GMT Just wanted to let you guys know, I finally tried this low cost 4-pin relay on my '78 e21 and it works perfectly :cool

The factory ones are now $179, this one is $39 and works with LED bulbs as well.

https://www.euromotoelectrics.com/pr...194digital.htm

I think only pre-facelift models use this type though. Looks like the later model ones are already cheap AF. ]]> 1975 - 1983 (E21) cgifool https://www.bimmerforums.com/forum/showthread.php?2498838-low-cost-4-pin-flasher-relay Intermittent A/C Issues https://www.bimmerforums.com/forum/showthread.php?2498837-Intermittent-A-C-Issues&goto=newpost Sun, 11 Jan 2026 00:14:12 GMT Hello,

I've been stuck trying to diagnose some A/C issues with my 2009 BMW 128i. I notice my A/C fails to cool when the car is idle, likely because the fan doesn't kick on even when I press my A/C button. I've manually turned on the fan via Protools and DME controls, so I know the fan is working -- and it kicks on when the motor temp gets too high I think it triggers at 115-130degC.

I went to a mechanic to fill up the A/C system to the correct levels and even replaced the expansion valve just in case something was going on there. Haven't noticed any leaks and over the course of several months I have no reason to believe there are any leaks since the pressures haven't changed much on the low side (a/c was filled in the summer when temps were close to 40 degC). I have a UV light and have not seen any leaks in the engine bay. Leaks may be hard to spot with the evaporator but I still have refrigerant in the system and the high side holds pressure throughout the months.

Now, I tried to document all my findings today with the following gauge readings:

Outside Temp: 14deg C.

Car turned off gauges connected (no e-fan, no a/c)
Low-65 psi
High-80 psi

Car running (e-fan running, a/c)
Low- 45psi
High- 150-175psi (then fan kicks off and drops down to about 125psi, low side climbs as this happens).

I have also attached a video showing what happens. Would appreciate some insight here, this has stumped me for months.

I don't know if I should consider a new compressor (because it kicks on when I activate my A/c and pressure builds). But something is not allowing my high side to build up pressure past 175psi or so (is this because of a faulty pressure sensor?)

https://youtube.com/shorts/mN7pfRYx7aA?feature=share ]]> General BMW and Automotive Discussion sponsored by Intercity Lines Project 128i https://www.bimmerforums.com/forum/showthread.php?2498837-Intermittent-A-C-Issues 1995 740i Transmission Failsafe | Continued https://www.bimmerforums.com/forum/showthread.php?2498835-1995-740i-Transmission-Failsafe-Continued&goto=newpost Sat, 10 Jan 2026 22:21:14 GMT Hello again everyone, So I have now owned my pile of junk E38 for about a year now, I have been... Hello again everyone,

So I have now owned my pile of junk E38 for about a year now, I have been slowly working on it here and there, I did the transmission fluid & filter with ZF LifeGuard 5 fluid, OEM filter, and I did the water pump and thermostat and replaced some hoses, swapped out the original rusted out fuel tank, as well as done some cosmetic work. Anyway...

I made a post about a year ago asking for help with the transmission, I wanted to see if anyone had any input before I go off the deep end and start building my own ADS interface so i can finally actually talk to and see what the modules in the car are saying, I was using PA soft but it doesn't give me any live data and the codes are super generic, I have an "error code 27" (how is anybody supposed to know what that means?) in the EGS and "EGS Signal Line Disturbed" in my IKE.

I used to be able to still drive the car around by just selecting the lower gears in the shifter. I saw a post from years ago about a guy who also had this problem and drilled open his Range Selector Switch only to find that it was pretty much brand new looking, but then he found the issue to be the actual body harness having cuts and damage in it, though I cant find the link to the post right now. Well, I went to pull my switch and open it up, and same deal, everything was all clean and no water. So, I pulled the body harness for the transmission out to inspect it for damage, and found nothing, no slices, severed wires, or abrasion. I also cut back the conduit on the range selector switch and again, all wiring looked perfectly in order.

Well, after I plugged everything back in and went to test drive, I still didn't have the "orange box" that illuminates the selected gear on the dash over the PRND234, but also, now the car was completely undrivable, no matter what i did with the A/M switch or the shifter, it would not leave 3rd gear and the torque converter would just slip and slip. I know my transmission is not mechanically broken since I was driving it and it was shifting great under my direction before i messed with crap I shouldn't have messed with, and now here we are.

Also another tid bit, I noticed my reverse lights don't come on at all in addition to the cluster not knowing what gear the transmission is in. I cant remember if this is new if its always been like this. So I guess it seems like the switch is just totally dead. Which seems really strange because I saw nothing wrong with it and i could feel the contact fingers physically clicking into their respective positions.

So now I am trying to figure out next steps. My current plan before just buying a $500 switch and hoping it will fix the issue was to build my own ADS Interface following this guide i found online: https://deviltux.thedev.id/posts/o/2...interface.html (the TinyADS has been out of stock for a while and import law limitations into the US make it a hassle to order internationally) so that I can actually talk to the computers to figure out for sure what is going on.

So my question is if anyone has any other suggestions on possibilities of it being anything else or some extra info to share that would be appreciated, or can confirm my hypothesis, as well as what will I need to actually be looking for after I finally figure out how to get INPA up and running in order to accurately diagnose the issue?

Hopefully I can finally drive this thing around soon. It feels like I'm getting close.

I have become more familiar with the car over the past year but I'm still a total noob when it comes to the electrical system and communication channels.

Thanks in advance for any help and for the help provided through the past year. ]]> 1995 - 2001 (E38) Redmenace52 https://www.bimmerforums.com/forum/showthread.php?2498835-1995-740i-Transmission-Failsafe-Continued M50b25 Stroker Build List https://www.bimmerforums.com/forum/showthread.php?2498834-M50b25-Stroker-Build-List&goto=newpost Sat, 10 Jan 2026 21:59:50 GMT My head gasket has finally decided to crap out. I've been wanting to do this build for a while now, so I figure if half the motor is disassembled I might as well do the other half. I want to take my 2.5 to a 3.0L. I know I'll need an m54b30 crank and pistons, but is there anything else I'd need or should do for this build? I've been unable to find a complete comprehensive parts list for this, so I'm looking to see if anyone has any information on this topic. On top of replacing the head gasket, I figure I'd do bearings, rings, and head studs as well. I figure I'll need a tune, and maybe some injectors, but is there anything else I'm forgetting? Cooling system has already been upgraded and overhauled, so I won't have to worry about that. ]]> 1991 - 1999 (E36) hellrotted325is https://www.bimmerforums.com/forum/showthread.php?2498834-M50b25-Stroker-Build-List Vehicle Service History Help - newbie https://www.bimmerforums.com/forum/showthread.php?2498833-Vehicle-Service-History-Help-newbie&goto=newpost Sat, 10 Jan 2026 20:50:57 GMT First Post 🙂

I just purchased my first z3!

1999 z3

I wanted to know if any members can help me find out the complete service history if I provide the vin?

btw�

I do have the Carfax �not a lot there

thank you

troy

- - - Updated - - -

Excited to be a part of this community ]]> 1996 - 2002 Z3 (E36/7, E36/8) TMDLKWD https://www.bimmerforums.com/forum/showthread.php?2498833-Vehicle-Service-History-Help-newbie <![CDATA[Set of 18' Momo arrow wheels 5x120 - Good condition]]> https://www.bimmerforums.com/forum/showthread.php?2498832-Set-of-18-Momo-arrow-wheels-5x120-Good-condition&goto=newpost Sat, 10 Jan 2026 19:54:13 GMT I have a set of rare MOMO arrow wheels for sale with a strong conclave look in good dimension... I have a set of rare MOMO arrow wheels for sale with a strong conclave look in good dimension (8.5x18 ET15) after upgrading them last year. Going for 630.00$.
They are in good OEM condition but with some mild scratches, I had all rims and a good tyre changer and all are well balanced! I couldn't post pictures or rather didn't see a way to attach them yet
(Pictures can be sent by text or email easily)

Specifications:

PCD:120
Holes: 5
Width: 8.5
Diameter: 18 inches
ET: 15
Manufacturer: MOMO
Model: Arrow ]]> Wheels and Tires Jeff090 https://www.bimmerforums.com/forum/showthread.php?2498832-Set-of-18-Momo-arrow-wheels-5x120-Good-condition Rear climate control https://www.bimmerforums.com/forum/showthread.php?2498831-Rear-climate-control&goto=newpost Sat, 10 Jan 2026 18:43:53 GMT Hi all My 5 series (estate) bought in 2024 has to the best of my believe the iDrive 8.5. The... Hi all


My 5 series (estate) bought in 2024 has to the best of my believe the iDrive 8.5.
The rear seat climate controls always default to fan speed = very low and temperatures of 22 degrees celsius on both left and right side. I have to thus change it each time and it�s annoying.


Can anyone help in advising me how I can have it always set to the last used parameters?


Thank you ]]> General BMW Mechanical Help sponsored by RM European Auto Parts tonyinfrance https://www.bimmerforums.com/forum/showthread.php?2498831-Rear-climate-control Binnacles behind the seats on the rear parcel shelf https://www.bimmerforums.com/forum/showthread.php?2498830-Binnacles-behind-the-seats-on-the-rear-parcel-shelf&goto=newpost Sat, 10 Jan 2026 17:18:02 GMT Looking to repair the covering on the binnacles behind the seats on the rear parcel shelf. the... Looking to repair the covering on the binnacles behind the seats on the rear parcel shelf. the covering is peeling up off of the base. How best to get it to settle back down (steam?) and what glue would be best? Any suggestions would be helpful
Thanks
IMG_4278.jpgIMG_4279.jpg
Attached Images
]]> 1976 - 1989 (E24) kpop https://www.bimmerforums.com/forum/showthread.php?2498830-Binnacles-behind-the-seats-on-the-rear-parcel-shelf Rear brakes staying applied � hydraulic pressure not releasing (BMW M2 F87) https://www.bimmerforums.com/forum/showthread.php?2498828-Rear-brakes-staying-applied-�-hydraulic-pressure-not-releasing-(BMW-M2-F87)&goto=newpost Sat, 10 Jan 2026 14:35:55 GMT Hello everyone, I�ve owned a BMW M2 F87 for 2 years. Everything has been great, except that for... Hello everyone,
I�ve owned a BMW M2 F87 for 2 years. Everything has been great, except that for about a year now I�ve had a strange braking feeling: after pressing the brake pedal, it feels like the brakes don�t release instantly but progressively, over 2 or 3 seconds.
After a 3-month trip, I took the car out again and on the very first press of the brake pedal, it was impossible to drive: the brakes stayed locked on both rear wheels.
On the side of the road, I removed the calipers to try to find the issue, but the calipers were still clamped. I had to slightly loosen the bleed screw to be able to push the pads back and remove the caliper.
What I observed is that the pistons move freely, but when I push one piston in, the other one comes out. It�s impossible to push both pistons back at the same time. The hydraulic pressure does not release in the circuit, and this happens on both rear wheels.
I�m now trying to identify the cause of this problem. Some people suggested replacing the brake hoses, but why would both rear hoses fail at the same time? Others mentioned the ABS module, but why would it only affect the rear wheels?
If anyone has an idea of what could cause this issue, or has already experienced something similar on a BMW or another car, I would really appreciate your feedback.
Thank you very much,
Looking forward to discussing this. ]]> 2016+ M2 TiipiakM2 https://www.bimmerforums.com/forum/showthread.php?2498828-Rear-brakes-staying-applied-�-hydraulic-pressure-not-releasing-(BMW-M2-F87) Rear brakes staying applied � hydraulic pressure not releasing (BMW M2 F87) https://www.bimmerforums.com/forum/showthread.php?2498829-Rear-brakes-staying-applied-�-hydraulic-pressure-not-releasing-(BMW-M2-F87)&goto=newpost Sat, 10 Jan 2026 14:35:55 GMT Hello everyone, I�ve owned a BMW M2 F87 for 2 years. Everything has been great, except that for... Hello everyone,
I�ve owned a BMW M2 F87 for 2 years. Everything has been great, except that for about a year now I�ve had a strange braking feeling: after pressing the brake pedal, it feels like the brakes don�t release instantly but progressively, over 2 or 3 seconds.
After a 3-month trip, I took the car out again and on the very first press of the brake pedal, it was impossible to drive: the brakes stayed locked on both rear wheels.
On the side of the road, I removed the calipers to try to find the issue, but the calipers were still clamped. I had to slightly loosen the bleed screw to be able to push the pads back and remove the caliper.
What I observed is that the pistons move freely, but when I push one piston in, the other one comes out. It�s impossible to push both pistons back at the same time. The hydraulic pressure does not release in the circuit, and this happens on both rear wheels.
I�m now trying to identify the cause of this problem. Some people suggested replacing the brake hoses, but why would both rear hoses fail at the same time? Others mentioned the ABS module, but why would it only affect the rear wheels?
If anyone has an idea of what could cause this issue, or has already experienced something similar on a BMW or another car, I would really appreciate your feedback.
Thank you very much,
Looking forward to discussing this. ]]> General BMW Mechanical Help sponsored by RM European Auto Parts TiipiakM2 https://www.bimmerforums.com/forum/showthread.php?2498829-Rear-brakes-staying-applied-�-hydraulic-pressure-not-releasing-(BMW-M2-F87) RetroAI Drive by D�vid Navr�til https://www.bimmerforums.com/forum/showthread.php?2498827-RetroAI-Drive-by-D�vid-Navr�til&goto=newpost Sat, 10 Jan 2026 10:56:14 GMT When an Old Car Starts �Thinking�: How Artificial Intelligence Can Boost Safety in a 20-Year-Old... When an Old Car Starts �Thinking�: How Artificial Intelligence Can Boost Safety in a 20-Year-Old Vehicle
Most of us drive cars without lane-keeping cameras, adaptive cruise radar, or systems that detect driver fatigue. Yet every day, we navigate traffic full of modern technology � and risks. But what if even an older car could perceive, alert, and assist the driver?
This is exactly the idea behind RetroAI Drive � an intelligent system that brings artificial intelligence and active safety features to vehicles built long before today�s advanced driver-assistance systems became standard.
A Car That Listens and Thinks
RetroAI Drive is not just another blinking box. It�s a digital co-pilot running in the background, observing what happens both inside and outside the car.
The system:
listens to sounds inside the cabin,
reads basic diagnostic data from the car,
learns the driving style of the individual driver,
and warns via voice or text when a potential hazard arises.
It does not steer, brake, or override the driver. Its only mission is simple: alert the driver when they may not notice a situation in time.
Detecting Sirens Before You Hear Them
One of the system�s most practical features is the detection of emergency vehicle sirens � police, fire trucks, and ambulances.
Rather than simply assuming �loud noise = siren,� the system analyzes:
the sound frequencies,
the characteristic rhythm of sirens,
and even whether the sound is approaching or moving away.
The result? The car can warn the driver before they consciously notice a siren in the city noise or on the highway. Early alerts can mean faster lane clearance � and, in some cases, even saved lives.
Every Driver is Different � and the System Respects That
Some drivers are calm, others dynamic. Some are fresh in the morning, others tired after a long day. RetroAI Drive does not try to fit everyone into the same mold.
The system gradually builds a profile of how you drive:
how sharply you press the accelerator,
how steady your speed is,
how your behavior changes over time.
If it detects unusual deviations � such as chaotic acceleration or odd vibrations � it alerts you. Not as a judge, but as a co-pilot who notices that �something isn�t quite right.�
Not Spying, Just Safety
A key question: does the system collect personal data?
No. RetroAI Drive operates entirely locally, without sending any information to the cloud. It does not track your location or identity. It only monitors technical signals necessary to assess driving safety.
Everything happens inside the car � no cameras, no voice recording, no GPS tracking.
Why It Makes Sense for Older Cars
Millions of vehicles on the road are over 10�15 years old. Many are mechanically sound, yet lack modern safety features. Replacing a car is not always feasible � financially or environmentally.
RetroAI Drive demonstrates that:
even an old car can become smarter,
safety can improve without buying a new vehicle,
and artificial intelligence does not have to be limited to luxury models.
A Car as a Partner, Not a Machine
Perhaps the most interesting aspect of the project is its philosophy. The goal is not to replace the driver or take control, but to create a partnership between human and technology.
A car that:
warns you when an ambulance is approaching,
notices when you drive differently than usual,
quietly keeps an eye on your safety.
No hype. No ads. Just smart, thoughtful assistance.
The Future Doesn�t Have to Wait for a New Car
RetroAI Drive proves that the future of mobility doesn�t always require replacing everything old with new. Sometimes, adding intelligence to what already works is enough.

And perhaps one day, it will be normal for even a 20-year-old car to have its own digital co-pilot � guiding you safely home. ]]> General BMW and Automotive Discussion sponsored by Intercity Lines RetroAI Drive https://www.bimmerforums.com/forum/showthread.php?2498827-RetroAI-Drive-by-D�vid-Navr�til 1995 740iL diag crank, no start https://www.bimmerforums.com/forum/showthread.php?2498826-1995-740iL-diag-crank-no-start&goto=newpost Sat, 10 Jan 2026 03:25:17 GMT Hello all, I�d like to preface this with saying I�m new to forums so I hope I�m posting this in the... Hello all, I�d like to preface this with saying I�m new to forums so I hope I�m posting this in the right place. Seeking the help of some internet diag wizards. Back in November I drove the car with no issues 2 hrs away to thanksgiving. 20 minutes after leaving, car was struggling to maintain highway speed, losing more and more power until it died. Proceeded to try side of the road diag, car would crank and fire while key being turned to crank and accelerator held to the floor. Only code showing from stomp test was 1222. Fast forward to today and I�ve finally had time to diag. Started with a new battery as old one got ruined sitting dead in the cold, did a new fuel pump since I assumed that was the issue. Car now cranks with no start at all. Plugs are wet and will car will not fire when adding starting fluid. Crank sensor showing 493 ohms and cam sensor showing 1100. Unplugged maf and iac separately, no change there. I am at a loss here. Any suggestions? Really trying not to cave and send the car to a specialty shop, as I�m sure the labor and tow alone will be more than the car is worth. Please help!


Sent from my iPhone using Tapatalk ]]> 1995 - 2001 (E38) Graypoupon https://www.bimmerforums.com/forum/showthread.php?2498826-1995-740iL-diag-crank-no-start 2002 Sedan FZV wiring - antenna/remote locking module https://www.bimmerforums.com/forum/showthread.php?2498825-2002-Sedan-FZV-wiring-antenna-remote-locking-module&goto=newpost Sat, 10 Jan 2026 02:58:14 GMT I am converting an IR locking car to RF. I have the later model FZV module to replace the older... I am converting an IR locking car to RF. I have the later model FZV module to replace the older antenna only module and have run wiring down the side of the vehicle to the GM module behind the glovebox.

The new FZV module has a 3 wire plug that the older one doesn't, assume one wire is 12V, one is ground and one is signal.

I can't find any wiring diagrams for these, only for the E53 and E46 which are different.

Anyone have a lead on any info here?

Cheers
Matt. ]]> 1996 - 2003 (E39) mattmannz https://www.bimmerforums.com/forum/showthread.php?2498825-2002-Sedan-FZV-wiring-antenna-remote-locking-module M62TU Vanos failure or something else? https://www.bimmerforums.com/forum/showthread.php?2498824-M62TU-Vanos-failure-or-something-else&goto=newpost Fri, 09 Jan 2026 22:17:09 GMT So when I was pulling back in my driveway today I noticed a new noise. Quick Google search said... So when I was pulling back in my driveway today I noticed a new noise. Quick Google search said maybe crankcase valve but the noise does not change when I remove the dipstick like one video indicated and I can definitely hear the sound the loudest at the drivers side front valve cover using my automotive stethoscope.

https://youtu.be/jClnDZGQI9Q?si=7Qzu5eQ3tw4KI3n_


Sent from my iPhone using Tapatalk ]]> 1996 - 2003 (E39) RedBirdin96 https://www.bimmerforums.com/forum/showthread.php?2498824-M62TU-Vanos-failure-or-something-else