Took on a 04 525i E60.. Where to begin
 

Love the look of this car forever so I decided to pick up a used one fully knowing I would be taking on any maintenance and issues that came along with it.

The Good:

Runs smooth/shifts great for the most part... Interior and exterior are in reasonably good shape.


The Bad: 200k Miles.

Throwing an emissions code. Of course the seller swore it threw no codes... 1 week later..

Faults: 002883/002882 - Mixture prep banks 1 and 2. From my understanding I likely have a vacuum leak. Cleaned the MAF with MAF cleaner.

Likely that the thermostat is broke (threw a 00279B - Thermostat map cooling) as the car only gets luke-warm and the radiator hoses are 'safe' to touch while car has been running, granted it is winter now. I know I can check through the hidden menus for temps but I'm almost certain this is the issue.

Replaced heater valve as it was opening when AC was engaged/closing when heat was engaged. Easy problem fixed there.

Battery current sensor is dead.

Rotors and breaks needed (easy fix there just $).

Some seat belt and airbag codes for the driver/passenger - less concerned for now.

High battery drain constant on start up.


And probably the worst part: Upon cold start it puffs smoke for a brief couple seconds. I'm told the valve seals are likely leaking into the exhaust. After 2000 miles I had to add 2 quarts just to bring it back up to a reasonable level.


I'm going to tackle the thermostat issue pretty quick here. That should be an easy win. The rough is going to be finding the vacuum leaks. And the most time consuming and difficulty will probably be the valve seals.


If anyone has any experience working with these issues I'm all ears. It's going to be a fun couple months of on and off work while I have time to fix this thing up.

Puff of smoke on startup could also be failed PCV valve/hoses. It's a very common failure point on M54 engines and is easy and cheap to fix. I wouldn't condemn valve seals until I knew I had a good working PCV system. I have an '04 530i...same engine, different displacement. Welcome to the E60 world.

I'll take a look into this. Thanks for your input!

Also found today upon startup I have some clicking noises and flashing door panel lights on the passenger side for about 20 seconds. Will investigate further.

I wouldn't be concerned about the seat belt restraint and lights clicking until I fix the battery issues. That could very well be the issue. Get it checked and the alternator. You could also have a bad voltage regulator. If you need to replace the alternator don't go cheap.

I would not point to seals first. Leave that as the last option. I hardly hear of those going bad on those engines. You have 200k on the car. I'm sure you vacuum hoses are cracked. Look at you crankcase vent valve and breather hoses. Check all vacuum hoses.

These cars are strong and the way it's seems it was not taken care of. Tackle items in same place all at once so you don't have to tear it apart again.

I'm sure the car can be brought back to good condition over the next couple of months. Know where to buy parts from (pelican parts, rock auto eBay. Some parts you can go for the lesser price but the parts that make the car run look for OEM. Also make sure the spark plugs are the correct kind and the right oil has been put in by changing it. Most use 5w30 me personally I use 0w40 (because it makes me feel better lol). Take you time and do research and you will be fine.

Where do you live in Missouri?

I've been looking at parts on FCP Euro and they have a Cold Climate PCV breather system kit which is supposed to be an upgrade to the current/standard replacement. It contains all the hoses/valve and intake boot. Its $20 dollars more than the standard replacement kit. I think I will attempt this route as soon as possible as well as get the thermostat done. I can't imagine running it like this much longer is great for the engine in general.

And lastly I'm current in the STL area.. Working downtown really takes a beating on this thing from all the lovely potholes.

Thanks for your input as well!

Oh, and also.. When I put a trickle charger on the battery overnight it does alleviate the door clicking/light flickering on the passenger door. The voltage issue will probably be tracked last unless its a simple battery going bad problem.

Happy to report:

Replacing CCV/PCV and breather hoses fixed my emissions issue. As well as thermostat, successful. Car runs 10x smoother.

Upon removing old breather hoses some of them were so dry rot that they broke upon removal.

New noticed issue. Front right side of car sits 2-3" lower than the rest. After removing wheel the only thing I can assume is the coil/spring is bad so I'm ordering new front coil/strut assemblies. Didn't find anything special on the few sites I checked. If anyone has any good recommendations I would be happy to cancel my current order from Amazon.

Thanks everyone on your input thus far.

Its definitely not broken. It does appear mildly 'wider' if that is such a thing compared to the driver side.

You should definitely check the DISA (danger of serious engine damage).