Oz-molus

Hi, I've used these forums a bunch over the past year and figured I'd go ahead and join them myself. I took a small engines class for a year back in highschool, but other than that I've never really worked on cars until I bought this BMW, but I have a ton of diy mod/repair background. I have a 2004 530i that I picked up for $2,000 at the beginning of 2020. I'm the 5th owner at least that I know about, and it's been pretty neglected and abused over the years.
So it's got an aftermarket RPI twin catless exhaust. The cat must just be drilled out though because it's still on there like it would be. Apparently it had an aftermarket intake system on it at one point, (I know 2 of the previous owners, so I've tried to piece it's life together through them the best I can) but it was taken back off and The original air filter put back on it. The odometer is at 219,976 (as of my posting this on 4-12-21). It was at 200,00 when I got it in January 2020. The engine was apparently replaced about 80,000 miles ago, but everything else is original, I believe.
When I first got it, there were all kinds of issues with it, but I figured for a 2grand BMW, if it blows up on me in a year I'll have gotten my money's worth. So it was stuck in the transmission failsafe mode, that was the big issue. Previous owner didn't want to replace the transmission. So I got under it and checked the fluid. It was bone dry. So I filled it up, turned on the car and topped it off, then reset the codes with the obdII reader. Went out of limp mode and didn't even shift hard.
So transmission issue was fixed. Next, the exhaust had a crack in the pipe. So I had a shop cut the piece out and weld in a new piece. $70 and it was good to go.
Now I was still getting a ton of error codes for misfires on all cylinders except 5, plus 1 random misfire. Vacuum leak codes too. Car was still idling really loud, it would stall on me if I braked too hard, and I had huge power loss for what a 530i should have. So I ordered some new hoses for the intake manifold. I took the manifold out, the idle control was completely stuck so I cleaned it out with brake cleaner, the intake valve was filthy so I cleaned that real good, the hoses were so brittle they just snapped with the slightest pressure, and they were caked up and filthy on the inside. Then I pulled out my disa valve and the flap wasn't even in it, it was just rattling around in the manifold. So I got that out, never found the pin for it, unfortunately, and got a rebuild kit for it, then put it all back together.
Immediately saw a drastic improvement on the car's power and fuel economy. It was so bad before I was getting about 200 miles out of a full tank, and now I'm getting around 350.
There's an oil leak somewhere that I still have to find, right now I'm doing about 100 miles a day 5 days a week on it and I have to fill up the oil about once a month, so it's not terrible, but the engine bay is filthy and it really bothers me. Also, one of the previous owners ripped off part of the splash guard on the bottom so it just doesn't have one covering the transmission pan and part of the engine bay.
I'm still new to posting here, but if i can upload pictures of everything in it's current state as well as repairs I've already done to it I'll add those so I can start to log my progress with it here.
On another note of just modifications I'm doing to it, it has the logic7 Soundsystem in it, I've spliced into the 4 wires going into the factory amp for my preamp RCAs to go to the amp input. I've seen people on here get into car audio, I'm just not sure how heavy people get into it. The OEM alternator I have is outputting 150A, the most I've had in here was 2 12"pioneers on a taramps 3k running 3,000RMS until one came unplugged and dropped the ohm rating on the other sub and fried it. Now I'm currently running 1 12" in a single ported box @1Ω doing 1,200RMS. The alt can handle it pretty well, I just bought a new lithium battery as my last battery was pretty wore out. Eventually I'm planning on doing the big 3 electrical upgrade on this, but I won't need to until I build a custom 4th order for the trunk. I want to cut a hole where the ski port would be and directly blow my sub port through the back seat.
Currently I'm about to add the aux input to the idrive. I have the 6disc changer, so no extra slot for the aux connector, I'll have to pull the pins and add them to the 6disc plug then reprogram one of the disc slots for aux. I have a K+DCAN cable already, I spent an entire day setting up a 32bit xp computer to run inpa and couldn't quite get the driver's working so I need to get that done before I install the aux, but it shouldn't be too tough. My big issue with it right now is I got the aux/USB plug for it since I use flash drives for music a lot, and the USB part has it's own cable and it's a 4 pin circular connection and I can't find it in the dash anywhere. It's advertised for the e60, but I haven't seen any posts here talking about retrofitting a USB in a 2004 530i, and I think after 2007 aux came standard so people weren't too worried about it.
But anyway, that's where I'm at with this $2,000 BMW, and I'm very happy with it, it's the first nice car I've ever had. People say they're junk because they break down all the time and they're expensive, but from what I've seen, the dealerships and repair shops are expensive, and it's more for labor than parts. If you have the extra time to work on it yourself, the repairs are very easy, just tedious as hell and very time consuming. But I've yet to pay over $300 for any part I've needed, and the maintenance is really easy on them too, especially since so many people have them and no one wants to pay dealership prices, there's so much info about diagnosing and repairing them yourself. Glad to be in the forums

JayArras

Thanks for your story and to the forum!

donpb

If you have a DIY mindset, you'll do just fine. I know a lot of ex-BMW owners who hate them due to the maintenance costs, but none of them do their own repairs either. If I didn't do my own repairs, I probably wouldn't own one either. I've owned 3 BMWs at the same time, even.