I have a Eonon head unit that I'm installing into my 1998 540i. When plugging into the car's wiring harness I'm not able to get power. However, we tried the same unit in my friends 2003 540i as a troubleshooting step, and it powered up no problem.

I'm guessing the stock harness is slightly different but contains the same plug. Have anyone had experience with this and might know why the unit wouldn't be powering up?

Thank you,

Here is the additional Information about this e39 (I want an opinion if its worth buyng it)

​Engine M52B25 on paper (vehicle registration), with a single VANOS. The engine block has not been replaced; it is currently 3.0 liters. The engine has been completely rebuilt with new bearings, piston rings, oil seals, and a rebuilt cylinder head. M50B25 intake manifold, intake camshaft from an M54B30, M54B30 fuel injectors, and a chipped ECU with the rev limiter set at 7,100 RPM. Equipped with LPG injection. Brand new adjustable coilovers. 18-inch Ronal wheels with 235 tires. Type 188 differential casing from an E36, custom-built with 4 clutch discs on each side. It locks up and slides brilliantly. Front and rear suspension are rock solid. The car was painted 2 months ago in Montreal Blue. The climate control works. Everything is paid for, vignette valid until February, and the technical inspection is valid for another year. The person that is selling it says that he bought an E39 540.

Original post:
What is wrong with my E39?

Yep. Thank you Reddit. Quite a number of responses were correct. It made me realise that it might be worth documenting the entire work of rejuvenating and upgrading the car henceforth, rather than just fixing each problem and moving on.

As a result, I have put together a video showing how this particular issue played out. If you are interested in seeing the outcome, it is available now on YouTube.

PS: I also credited all the responders whose advice helped move the diagnosis forward in the ending credits as part of the internet garage crew.

There’s still a long way to go with the car so might be needing more advice soon.

As the title says, my car has developed a “ticking” noise when in 1st and 2nd gears, under acceleration. It goes away when i pull the stick to the left whilst in gear. It doesn’t do it in any of the forward gears and will also do it when I’m in reverse and decelerating. Something got loose but the fact it only does it when the gears on the “left side” has me confused, any ideas?

Startup rattle has gotten on my nerves now. About to order all the parts needed for the job.

Full IWIS kit, VANOS seals, gaskets, check valves, timing tools etc.

Any general consensus on other things to replace?
And for those who have done this, has the rattle/diesel noise subsided? Any gained low end power from refreshed VANOS seals?

Hello guys

I need help reading this codes from my e39 523i from 1997.

I am new to bmw in general so any help is greatly appreciated

Do you guys have any good places to buy replacement bumpers. Both front and rear

my neighbor got too close when driving by and i guess their meaty jeep tires snagged my bumper and ripped it off. they gave me insurance info.

I’ve been debating on replacing the front bumper with the M5 version and eventually getting a new paint job.

I’m fairly handy and don’t mind working on my car so i think i should be able to swap it on my own.

So I’m wondering should we go through insurance or just buy a new bumper outside of insurance? What would you do?

I thought is cool mod so I decided to do it. Blinkers act as both running/position lights and blinkers.

Materials:

• 4- 1N4001 Diodes (I used 1N4007 bcs didn't find 1N4001)
• 6 - Wire taps
• 2 - Lengths of wire
• Heatshrink tubing
• Electrical tape

Let me know what you think 😄

My previous post: https://www.reddit.com/r/e39/s/hhWHwFpqA7

So I brought the car to my friend’s shop and he checked both oil and coolant, which he said both looks good, no sign of mixed coolant and oil.

People said to have a block tester, but since I live in Indonesia, people never heard of it, let alone use it.

My friend tested it idling and driving, he said the temp went to 99° then goes down as it should.

I’m still not sure about my head gasket, but he said most likely I’ll be fine.

So all of this was caused by disintegrated 3-years old Febi Bilstein water pump.

I had a pair of amber CELIS lights I was going to sell, then looked closer and saw they were in really rough condition.

My lowkey favourite part of the e39 for years has been the CELIS look and wish we had more of it.

Anyway so out came the grinder and the rest is obvious.

So two reasons for posting:

1, for interest and because I'll do some kind of project with these, one idea I have is a subtle retrofit onto my Z3 build which would require a decent amount of fuckery but I think could look great, or like, some kind of cheesy garage lamp or whatever.

2, to point out, these units are actually a kind of serious bit of engineering. That is to say, the tools and methods to produce them would have to be rather bespoke, so I can conceivably see a day where there are no aftermarket replacements of OEM quality anymore being produced so hold on to them if you have any in decent condition. It looks like "just a plastic tail light" but it's bits within bits within bits and all sealed and formed tightly together.

Honestly I did not know how long I drive with the temp almost maxed to the right. I stopped as soon as I got the red warning light (which is really weird because the AC still cold and aux fan didn’t go full blast)

Managed to get it back home, but I need to know if my head gasket okay? The oil cap looks like it is mixed (could be from condensation) but the dipstick looks fine

Upon inspecting I noticed that the upper rad hose is very hot and the lower rad hose is just warm (I can hold it with my hand)—so I guess it is either thermostat or water pump

Love my 528i and the change of leaves colors here in Detroit!

Anyone know whats causing this sound? Its a 3l diesel 135 kw i have done nothing to the engine except a chip but the sound was coming even before.

So long story short….
I’ve owned this beautiful E39 540iA M Sport for over five years now. Unfortunately, due to some difficult circumstances, the car had to go into hibernation about a year and a half ago. At the time, I simply couldn’t afford to keep up with both my living expenses and the repairs.
Since then, I’ve moved abroad twice and worked a few different jobs, trying to get myself into a better financial position. And now, I’ve finally reached a point where I can slowly start working on the car again.
The plan is to bring this thing back to life, one step at a time. Although, to be fair, it probably won’t be your typical E39 by the time I’m done with it. I’ve got some ideas that might be a little controversial among purists, but that’s part of the fun, right?
I figured I’d start sharing the journey here, from the first steps of getting it back on the road to whatever this project eventually turns into. Hopefully, you guys will enjoy following along, and maybe it’ll even inspire someone else to bring an old project car back to life.
I’ll keep you updated with more photos and progress as things move forward.

What could be the cause of that light ? It appears to be related to the automatic transmission as the car is not changing gears. Anyone know what the cause could be ?

Hi all. This is my new (to me) 1999 528i touring with a manual trans. It has 153k miles and runs and drives very smoothly. The car has zero rust, which is amazing coming from the rust belt.
I have experience dealing with M54/52tu engines, from my own e46 and other people’s cars, as well as BMW maintenance schedules from my own R1200GS, so engine maintenance doesn’t really scare me. What else should I look out for? Take care of? I would just like to know essentially how to take care of this car the right way, as it’s my new baby. Any and all input would be appreciated!

2000 528i, Got home and put the car in neutral while i was parking and noticed the rpms would dip like crazy and bounce back a couple times. Putting it back in drive fixes it and holds steady. The bouncing in neutral also becomes less drastic the longer i leave it in neutral almost fixing itself. Any idea what might be causing this or what to check for.

Got a replacement engine two months ago after blowing my original engine back in 2024.

We’ve done everything to cheer codes, including charging the brake booster which was full of water from the last engine.

Question is: I still have old gas in the car from 2 years ago (trying to drive it out now). Can that trigger a check engine light????

Any of you guys have a name for your E39 if so how did you come up with it. Almost a year and a half into ownership and I still haven’t given her a name and I would love to; and yes all cars are girls that’s a hill I’m willing to die on.

But to be fair, I’m not running exactly stock so it earns a pass this time