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.

[SiC]

Replaced the drivers side wing mirror glass as it was annoying me. Little things like this make a car feel scruffy imo and for £18 off Amazon it's cheap enough to sort.

Thermostat done ... again. Genuine for main this time and Mahle/Behr with scrubbed off marking suggesting it's OE. Now holds 97C or so when sat and the engine fan kicks in. Opening is 88C but there are electronic flaps on the front that open when needed. So it gets hot until the fan moves air around.

 

Also managed to have the left side bonnet release cable come off the hook which got the bonnet stuck shut 😩

Turns out you can go through the front wheel area and prod the latch open with a long screwdriver. Also this car is ridiculously over engineered. There are air ducts for the front brakes - nothing unusual. However they have vacuum operated flaps to control when they're open or not ... why?! Must save a fraction of a mpg.

Anyway I managed to get it open and this time I put a zip tie around the cable so it doesn't fall off again.

As the thermostat was a bit quicker to change this time, I had spare time to do the air filter.

My fucking god is this a shit design. You need the whole scuttle area and brace bar off just to get this damn thing out. Even after all that you need to bend the plastic at the back to get the bloody cover out.

What a monumentally shit design. Took a good hour to replace that with a lot of swearing.

 

Then did an oil change. Thankfully this is a lot easier and the oil filter is up top. Also nice to see a dipstick - my N52 330i and Z4 don't have this annoyingly.

.

Underneath is remarkably dry for a BMW. I couldn't see any oil leaks at least.

And yes there was oil in it!

Finally did the fuel filter. Probably didn't need doing but was in the box of service bits that robt100 left with the car. Bit of a pain in the arse to get to. Not least with diesel running all down your arm.

 

Then went for a test drive to make sure everything was okay...

... and it wasn't 😩

Engine light pinged up on the main road a few miles from home, engine cut out and I managed to coast into a side road. Fuel pissing all out of the area where I did the fuel filter.

I got Mrs SiC to pick me up and I went back down in the 330i with tools.

I thought it was a jubilee clip that had failed as they didn't feel like they were tightening up properly. With the cover off however it turned out to be the big retaining clip at the back had popped off. I thought I pushed it in but it was hard to get on. Tbh I don't think this Blueprint filter is the best quality. Being a FEBI brand, this is the second FEBI part that has caused grief in quick succession. Not impressed.

Anyway I bashed the clip all the way on this time with the backend of a ratchet. Drove home fine. 

Even if a large diesel spill was left behind 🙃

An FTP always knocks confidence in a car but at least this time it was my fault really. Just instead knocks confidence in your own abilities...

I haven't driven it since as I haven't needed to. But probably use it for more tip runs this weekend. It could do with a pair of front tyres as they've worn badly on the edges - wheel alignment is almost certainly out. Probably the cheapest ditch finders will be going on to be honest.

 Currently sat next to a car of the same age and to be honest probably similar value when brand new too. 

I was speaking to my neighbour the other day and he is getting a new electric car through his work. Hence his F31 320d xdrive touring (with towbar) will be up for sale. I have expressed an interest - not sure if he actually took me as serious though. It's an N47 so I would need the chain doing. However 125k on the clock between two owners (previous was his dad) and it's generally been well looked after I believe. Good spec too with panoramic sunroof.

Anyway this would mean a major cull of vehicles on the fleet. This would certainly go and possibly either the Z4 or 330i too. The 320d isn't ULEZ/CAZ so I'd keep one of those two petrols so I can nip in - possibly the 330i as I'd like to keep an auto. 

[SiC]

One issue that has been really annoying is that the clutch pedal drops a bit and doesn't return all the way up. It mechanically fully engages the clutch but it makes the bite point feel weird with the pedals out of line. You can pull the pedal up manually with your foot but that's annoying.

@robt100 mentioned that it was a problem with @motorpunk for all his ownership and never a problem.

Looking up at the pedal, it looks to be missing a return spring. (Not that clear on these photos)

 

Part 14 below

 

The same spring for the E39, E60, E61 and E65. 

Apparently people remove it as they prefer the clutch pedal feel. I think it's awful and my E89 is much better feel with a spring. 

You can get them new on eBay but the cheapest is £30 shipped ... for a spring. They don't appear to be available second hand. 🫤

I might find what the dealer wants but if it's just as crazy price, I'll see if I can get an equivalent spring. Cause sod spending that much on a bit of ordinary twisted metal. Unless anyone knows of a manual E39 or E6x being broken for parts?

[Matty]

Probably not the best time to mention it given that a cull is immenent but ive a nice Z4 coupe available soon 😉

[SiC]

12 hours ago, Matty said:

Probably not the best time to mention it given that a cull is immenent but ive a nice Z4 coupe available soon 😉

I always thought a Z4 coupé would look fantastic next to it's Cayman competitor at the time on the drive 🙃

[yes oui si]

14 hours ago, SiC said:

This would certainly go 

HNNNNGGGGGFFFFF