project 2007 BMW 525d High Mileage Hero

[motorpunk]

Mike Smith cars in Leicester (who are excellent, by the way) removed the RCL key coding. I’m seeing them on Friday as they have my 640d for brakes at the moment so will try and remember to ask how they did it. Or you can call them, they’ll remember the car, I’m sure. I vaguely recall him saying something about difficulty recoding it afterwards but I was more concerned about security with the other set of keys having been stolen.

Great updates btw. Fascinating to see how this at is working.

[Split_Pin]

Try blowing through the EGR thermostat, if you can then its stuck open.

The temp guage on my L322 barely got above a quarter so I bought a Renner 5 thermostat as a temporary measure and shoved it in the top hose plus replaced the EGR thermostat. On the test run it got up to 85ish but the best it could do thereafter is 76c. I did buy a proper thermostat as I thought that was the issue but I'm now not sure it is after reading your thread.

I might replace the fan viscous coupling (does yours have that?) in case it's dead and permanently engaged. 

Thankfully I dont have a DPF on the L322 so I'm just living with it for now but yeah yours needs sorted. Following with interest.

[robt100]

You're a braver man than me getting all that apart, I seem to have lost my confidence in car repairs recently, need to get back to being brave at getting things apart. Glad you're getting it sorted though and that everything seems in good condition, it always felt like a car with less than half the mileage!

[SiC]

11 hours ago, motorpunk said:

Mike Smith cars in Leicester (who are excellent, by the way) removed the RCL key coding. I’m seeing them on Friday as they have my 640d for brakes at the moment so will try and remember to ask how they did it. Or you can call them, they’ll remember the car, I’m sure. I vaguely recall him saying something about difficulty recoding it afterwards but I was more concerned about security with the other set of keys having been stolen.

Great updates btw. Fascinating to see how this at is working.

 

Please do ask if you get a chance. My suspicion is they deleted all the remote control IDs. I don't have the tools to sort that but an Auto Locksmith should do (there is a good one near me) - but it's easier for him (cheaper for me in his time) if he knows what was done to it. 

There are something like a maximum of 10 keys stored in these. BMW program all those key slots to known numbers. That way you can order a brand new key from a dealer and it'll just work by plugging it in. However if someone has deleted all the remote control key slot data, a genuine key directly bought from BMW won't work. Only a decent Auto Locksmith can then add a new key in. 

I'd like a new key as I'm always nervous only having one. Loosing it while out and having the remote control system in a weird programmed state could easily make it hard for anyone else trying to add a new key who don't know the intricacies of BMW security systems (like the AA/RAC). So loosing a key could end up making it bricked and being scrapped due to being uneconomical to repair. 

[motorpunk]

I asked them the question and I didn’t understand the reply. I got the impression that any good Indy should be able to recode that key you have to be remote again. Or call them yourself, I’m sure they’d be happy to help explain. 
 

[vaughant]

Could you go a bit hill billy like I was going to do with the Berlingo and parallel the connection to the lock button inside the car through a wireless relay from the paired fob that comes with it? 

Should be no challenge for someone of your talents.

 

[vaughant]

Something like that but they're about a tenner on Amazon?

https://uk.rs-online.com/web/p/communication-wireless-development-tools/2864043?cm_mmc=UK-PLA-DS3A-_-google-_-CSS_UK_EN_PMAX_Catch+All-_--_-2864043&matchtype=&&gclsrc=aw.ds&gad_source=1&gad_campaignid=20567417192&gbraid=0AAAAADkeWNMuGR0BwHVfJEXaeisnTuzKT&gclid=CjwKCAjw-8vPBhBbEiwAoA39WszaCGpYLX91gF57mBb0Nnq7mGpML-3f-TVjAmUC0qi3_FFkHTAnsBoC2DkQAvD_BwE

[horriblemercedes]

On 15/04/2026 at 21:08, SiC said:

- Washer jets are feeble. My E90 did this and was the washer filter screen gunked up. Annoyingly it is easily done if washer fluid is mixed. Back in the day, BMW wouldn't warranty this job if you didn't use their expensive genuine washer fluid... Should be an easy job if the tank isn't hard to get to.

 

If you're lazy like me, a little dab of bleach in the washer fluid tank will cure this. I did it for years and had no problems.

[SiC]

If you're lazy like me, a little dab of bleach in the washer fluid tank will cure this. I did it for years and had no problems.

I fixed that with my usual trick of a gentle blast on the washer line hose. Disconnect both washer jets, thumb on one hose end and blast the other. But going gently as you don't want to pop any hoses off. Having the thumb on the end is a handy way of providing some sort of pressure relief valve. Then blast both washer jet inlets too.

Back to full pressure now. Rear could do with the same but need to be real careful as popping any of those hoses off makes it a right nightmare to fix.

[motorpunk]

2 minutes ago, SiC said:

I fixed that with my usual trick of a gentle blast on the washer line hose. Disconnect both washer jets, thumb on one hose end and blast the other. But going gently as you don't want to pop any hoses off. Having the thumb on the end is a handy way of providing some sort of pressure relief valve. Then blast both washer jet inlets too.

Back to full pressure now. Rear could do with the same but need to be real careful as popping any of those hoses off makes it a right nightmare to fix.

Rear washer pipe is disconnected inside the roof lining! It’ll drain out safely somewhere, but will not wash the rear glass. When I had the wiring loom in the boot hinge repaired, they disconnected it and forgot to reconnect. Apparently you can reach it through the speaker covers inside the boot roof (if that makes sense). 
 

I never bothered with screen wash and always used tap water, so it once or twice got algae or whatever in the tank, so I’d add a kettle of boiling water and a tiny bit of bleach to clean the pipes. I also recall the washer pipe popping off the grommet inside the bonnet once, but it pushed back on.

Funny how I remember such detail in a car I sold years ago but can’t remember my own feckin’ phone number.

[SiC]

12 minutes ago, horriblemercedes said:

If you're lazy

I definitely am. 

But also my experience with aging 2000+ era German vehicles is that it's a fine balance of removing enough to make a job easy but not too much that you risk breaking all the plastic parts.

For example, I was watching video the other day on an "easy" way of accessing the EGR thermostat. He disconnected and moved a hard line vacuum hose out of the way by pushing hard. That video was uploaded 14 years ago...

Try doing that on these 14 years later, you're almost guaranteed to snap that pipe. I certainly wussed out when I thought it would work but the plastic wasn't being forgiving enough. If you snap that hose, it is a plastic intake manifold off job. Which also involves removing a bunch of other plastic pipes and electrical connectors.

Before you know it, you having to make and wait for a large autodoc order of replacement plastic parts that have now broken!

[SiC]

Some fun for the weekend...

Austrian BMW main thermostat 

Israeli Behr EGR thermostat (with scrubbed markings)

Chinese unbranded Glow Plug module

[dome]

20 hours ago, SiC said:

Some fun for the weekend...

Austrian BMW main thermostat 

Israeli Behr EGR thermostat (with scrubbed markings)

Chinese unbranded Glow Plug module

How's the access looking for the glow plug module? I'd imagine with your simpler intake setup than most of these it's not too bad. The hardest thing is getting the connector going to the alternator split, that was a mare on my 730d

[SiC]

6 minutes ago, dome said:

How's the access looking for the glow plug module? I'd imagine with your simpler intake setup than most of these it's not too bad. The hardest thing is getting the connector going to the alternator split, that was a mare on my 730d

Friggin 'mare. For those that haven't done it, it's to the left of the dipstick in this picture behind all the hoses.

I managed to do it without removing the manifold though. Now just have 3 plug codes.

According to the internet, it won't regen unless it's 2 or less codes active. However this link from BMW docs don't mention anything of the sort. Just >75C coolant temps and exhaust hot enough.

https://www.dropbox.com/scl/fi/d5v4mcprho24ic9qr0655/Doc20151008085826-2-7.pdf?rlkey=lfo47md5vfjf20crr3op8t77o&dl=0

Plus this familiar named chap back in 2016 that I found on a BMW forum reckons that glow plug codes don't stop a regen either.

@JJ0063 presumably this is you 10 years ago. I don't suppose you remember the specifics? 😂

It would make sense if it still regen with those codes as I reckon they've been stored for a very long time. A regen usually happens at most between 600-800 miles so it must have done plenty of cycled in the 257k+ miles it has.

Anyway at least it should start smoother in the winter.