BMW wiring and error codes

[Wagger]

20 hours ago, Colin Lindsay said:

Removed and cleaned passenger pretensioner and contacts; removed and cleaned the short cable from pretensioner to loom along the rear of the seat, and cleaned the contacts at that main connection too where it disappears under the floor. I don't think I can swap pretensioners round as there's a different short cable connection on either side so passenger cable won't fit the driver's side except at the actual pretensioner itself, which means removing both seats yet again. NOT AGAIN!!!  I might replace the pretensioner itself but have located a small BMW-specialist garage less than ten miles from me, so might call in with them for advice, as some enthusiasts are stating that the airbag warning light is not so easily reset as many claim. Worth a try later in the week. 

Don't despair Colin. There are some good BMW forums where you may find a solution. There are some clever guys who can program out some features and there used to be plug on bits that would 'Fool' the system into believing all was well. Quite how useful Airbags are on a CV I cannot suggest. I know two people thrown clear of a CV car who would not have survived if they had been wearing a belt. This was before belt wearing was compulsory.

[Colin Lindsay]

10 minutes ago, Wagger said:

Don't despair Colin. There are some good BMW forums where you may find a solution. There are some clever guys who can program out some features and there used to be plug on bits that would 'Fool' the system into believing all was well. Quite how useful Airbags are on a CV I cannot suggest. I know two people thrown clear of a CV car who would not have survived if they had been wearing a belt. This was before belt wearing was compulsory.

Nil desperandum, if that's how it's spelt. I don't really despair, just grumble out loud and take on the challenge. I've just fitted the new exhaust, not as well as I'd like (it seemed a slightly different profile to the old, so some of the flexible joints are not as square as I'd prefer) but no leaks or blow-outs. Currently trying to work out where the vibration damper goes as there are no clues. I need the car tomorrow as family are all working or on courses so taking theirs, so it'll be roadworthy by then. 

I'm not used to this kind of expenditure in recent years; exhaust, tyres, and small sundry parts have cost me 75% of the purchase price already. It had better behave! Conversely I'll be in a position where I can't sell it as I'll never get the outlay back. 

I did manage to get the Freelander through MOT, clean slate and in quite good condition, so that's a bonus. 

[Wagger]

4 hours ago, Colin Lindsay said:

Nil desperandum, if that's how it's spelt. I don't really despair, just grumble out loud and take on the challenge. I've just fitted the new exhaust, not as well as I'd like (it seemed a slightly different profile to the old, so some of the flexible joints are not as square as I'd prefer) but no leaks or blow-outs. Currently trying to work out where the vibration damper goes as there are no clues. I need the car tomorrow as family are all working or on courses so taking theirs, so it'll be roadworthy by then. 

I'm not used to this kind of expenditure in recent years; exhaust, tyres, and small sundry parts have cost me 75% of the purchase price already. It had better behave! Conversely I'll be in a position where I can't sell it as I'll never get the outlay back. 

I did manage to get the Freelander through MOT, clean slate and in quite good condition, so that's a bonus. 

I have used BMW breakers near me for used spares. Euro Car Parts and GSF for new parts. My local BMW dealers occasionally do a free health check which includes a full jet wash as they won't have dirty cars in the workshop. If I time things right they do a diagnostic check for about £50. My friendly mobile mechanic then does the necessary if I cannot fix it. I have only spent around £1k on my 520D in four years. (20,000 miles) Most of that been on Runflat Tyres.

[Colin Lindsay]

12 hours ago, Wagger said:

I have only spent around £1k on my 520D in four years. (20,000 miles) Most of that been on Runflat Tyres.

I know I'm newly-fangled with the Z3 hence some of the expenditure, like a pair of front struts that I now reckon I don't need but cost me £300. I had to fix the rear fog lights - stuck permanently on - for MOT, so needed a £30 switch plus a full service which included a new thermostat, but I also replaced the front brake discs and pads and gave the underside a full Wax treatment. The exhaust rattled alarmingly, so I replaced the silencer which admittedly did have a perforation at one of the welds, then found it was the CAT. It was embarrassing if driven down a street as pedestrians could hear it echoing off the buildings, so as it spoiled the image completely(!) it had to go too. THAT was £1700, no exchange as the BMW mechanics reckon the internals have been removed over the last 25 years as it's dated 1997. Replacement hood window was £100. Replacement stainless petrol tank straps were £75, the originals were crumbly, and only a tenner for new seat bushes. Rear tyres were about £180 a pair. Get that airbag system sorted and it'll see no more for a while, although the headlamp switch illumination doesn't work - that will really annoy me until I replace the £5 bulb after about ten hours labour as it requires parts of the dash removed, and the exhaust joint bolts are not the proper sprung bolts so I'll scour eBay for replacements. As with the Triumphs, little details get on my goat until properly sorted.

Incidentally I replaced the exhaust last night and the car is transformed; not only much quieter but more power at low revs. I was always surprised at how poor the acceleration was in lower gears. The CAT has been messed about with and no doubt blocked. All I need to do is work out where exactly the vibration damper sits on the main pipe, or if I even need it, and that's it done.

[Colin Lindsay]

Latest news on the old CAT is interesting. As BMW wouldn't take it back due to the welded patch on top I decided I'd see what was lurking underneath. I suspected the internals had fallen in, hence the rattling, and the resultant blockage had affected performance which was far from blistering. So: one patch ground off: here's another one!!

  

Grind that one off and...... nothing.

  

The CAT is completely empty, not a trace of internals. No trace of what was causing the rattle, no trace of what was blocking the engine gases and reducing performance, and absolutely no trace of how it sailed through MOT last August well within emissions limits when the aftermarket Euro 2 CATs fail regularly. You'd think a poor CAT would be better than none at all!

Strange... but the transformed engine is definitely a real points-getter so I'll just avoid looking at the bank balance and enjoy the car. If it would stop raining I might even get the hood down. 

[Steve P]

I reckon someone stole the precious metals overnight and then covered it up with the patches.

S

[Colin Lindsay]

15 hours ago, Steve P said:

I reckon someone stole the precious metals overnight and then covered it up with the patches.

S

And welded it up again from above... I can just picture a whole gang of inch-high welders walking about on top and ducking under the bodywork...

[Peter Truman]

A neighbour of ours ran a Taxi service of 50 taxi’s (each. Licence was worth about $300k) their solution to a blocked or restricted CAT was smash it through with a crow bar no further any obstruction, all taxi’s of that period ran on gas so it wasn’t too great a pollution issue.

He told me  that quick solution after I’d just paid $900 for a new CAT for the then daughter in laws Hyundai 

[PeteH]

On 21/03/2024 at 09:43, Colin Lindsay said:

And welded it up again from above... I can just picture a whole gang of inch-high welders walking about on top and ducking under the bodywork...

Apparently, there is a whole "back street" enterprize, which will remove the internals and re-fit the then empty cat. allegedly to "improve" performance. They make their money from the sale of the precious metals. How it ever gets past (an Honest) MOT tester is a matter for some debate?. I note the latest tesing machines, actually upload the results onto the DVLA database in real time, Or so my Tester says?. My old Peugot 107 is marginal, and keeps bringing up the error on the dash, which for the moment I can delete. There is some thought it could be the O`2 sensor?. £25 as oposed to a mninimum of £150 (ish) for a "pattern" Cat, or "big bucks", probably more than the car is worth, for an O/E one.

Pete

[Steve P]

I had a Pug 408 Estate GT170 which was a great quick car but at 170K it kept going into limp mode and actually cut out completely at 70mph on the A3M towards Portsmouth once, it was the EGR system, sold it on E bay as it wasn`t worth fixing.

S

[Colin Lindsay]

2 hours ago, PeteH said:

 I note the latest testing machines, actually upload the results onto the DVLA database in real time, Or so my Tester says?

You can't fake the emissions over here, the machine must register a proper sample and then pass it, so if it fails the machine will let you know. You get a readout of the results on the MOT certificate which is also sent to DVA electronically. Mine was 0.770 CO idle and 503 HC idle, I must check that against the permissable limit. That's with NO CAT at all.

The BMW online forum is currently tearing their hair out over why I only have one O2 sensor in the exhaust, pre-CAT, and none post-CAT, but the original 25 year old exhaust and the new replacement from BMW are identical with only one socket for a sensor so it's not a PO mod. All of their M44 engines have two so as the engine didn't alter any settings to compensate we can't account for the drop in performance and as I've examined the old exhaust minutely there's no blockage. 

 

[johny]

I think its still possible to test an alternative vehicle in place of the one needing an MOT but this wont be possible for much longer as the tester will be plugged into the OBD and know everything...

[PeteH]

8 hours ago, johny said:

I think its still possible to test an alternative vehicle in place of the one needing an MOT but this wont be possible for much longer as the tester will be plugged into the OBD and know everything...

My "guy" already does this for the Sprinter. His equipment is plugged into the OBD port. But not on the P-107?.

Pete

[johny]

The thing is they can take readings from the OBD already but Im not sure theyre actually sending the associated vehicle identity info direct to DVLA yet but they will...

[Wagger]

Colin, when I first had an E60 five series in 2017, all forums were full of de-catting procedures and egr bypasses that would fool MOT inspectors. Looks like yours is an example. These cars will pass without Cats and by passes as the fuel management systems are quite good. However, it usually requires re-mapping to gain more performance.

I did block the vacuum tube on my E46 3 litre diesel's EGR valve to stop it fouling a replacement inlet manifold. It improved fuel economy (surprisingly) and pickup after decelleration. The gunge in the first manifold dissolved the ultrasonic welds and the manifold split under turbo pressure. I bolted the replacement to prevent recurrence. The deposit was over 3mm thick on the old one.

Edited March 24 by Wagger

[Colin Lindsay]

NOW the on-going debate on the Z3 forum is that my car actually shouldn't exist, as with only one sensor it should be a pre-1998 1.8. Despite the V5 stating 1897cc and the engine number being original and pointing to 1.9, the 'experts' reckon it's incorrect. Having once been told that my GT6 was never made by Triumph then I'll take ideas like that with a pinch of salt, especially when BMW themselves seem to know what it needs. This is the reason I bought this particular car - very few sensors compared to later models and equipment meant to enhance the driving experience, not make it into a home cinema and four-wheeled mobile phone so that if it can't dial Just Eat it needs to go back to the dealer for a full upgrade.

I bypassed the EGR on my TD5 Discovery - in fact, removed it completely - with no detrimental effects, but now the law has changed and the EGR must be present and working. They don't test diesel emissions at all, which is now the subject of debate and legal challenge, but petrol cars have always been tested. It will be interesting to see the next test result with the new CAT fitted. 

[Colin Lindsay]

Lord, I'm starting to wonder why I ever bought this Z3. The airbag light is now on permanently, "passenger side seatbelt pre-tensioner error" according to the code reader. I can't reset it so the fault is still there. It may be the tensioner, the first connection, the cable, or the second connection, or the main loom - all disturbed when I removed the seats to repair the bushes. I can replace the tensioner, or the short cable; I've already checked and cleaned the connections all the way to the main loom. Each component will cost money to replace and if the fault remains then that's wasted money - which we all hate doing! Checked it again yesterday and now there are TWO faults, the driver's side has also shown an identical warning. That's both sides now, with replacement tensioners costing £140 at least and that's only on eBay; if it's not the pre-tensioner itself, or the cables, then it's the main loom, which can be salvaged by very delicate splicing. Add to that a slight reluctance to start when hot on Thursday, and a possibly-related misfire on Friday that went away after a few minutes... now the paranoia is setting in. Every corner: is that the suspension waving about? Seems slow to accelerate: is that the camshaft position sensor going or am I not pressing the accelerator enough? I see it becoming a money pit and am starting to lose enthusiasm for it. These cars are being scrapped in quite large numbers due to faults like these and the cost of replacement parts - it has certainly made me appreciate the Heralds! 

At least one thing was settled: the car is UK-spec and has only one exhaust sensor, pre-cat. That led to a lot of anti-UK comments concerning emissions on the Z3 forums, but not my problem - I'm road legal and original. 

[alan.gilbert_6384]

Hi disconnect the battery, wait 24 hours the connect the positive to the negative on the battery for 10 mins, leave for an hour then reconnect make sure you know the radio reset code before as this will will Alt - Ctl-delete the the whole system.  Good luck it sometimes works.

[GrahamB]

2 hours ago, alan.gilbert_6384 said:

connect the positive to the negative on the battery

I presume that you mean the positive and negative leads to fully discharge the system and not the terminals?