Your fleet running reports

[John]

Caterham K-series owners must be positively chilling in this weather compared to drivers of the Ford Sigma and Duratec variants. The exhaust, cat and manifold located on the driver's side make them a bit toasty in the footwell/leg area

[integrale_evo]

It doesn’t have catalysts, but I don’t really enjoy driving the ‘sud if it’s over 25c. You can get ok airflow into the cabin as long as you’re moving, but lack of insulation means lots heat soak through the bulkhead and floor, plus lots of clear glass for its size and thin pillars mean it’s a bit like a greenhouse!

[Sundayjumper]

M3 - MOT passed last week, no advisories. But they reckon the emissions are quite high? Not sure why, it had a new airfilter and oil change over winter and I run it on SUL. 1400 miles between MOTs, so pretty low amount of miles.

Small air leak ? My Compact had high emissions, eventually traced to a slightly leaky exhaust manifold gasket. In between pulses of exhaust gas you get a slight vacuum as the momentum of the gases pulls against the now-closed valves, it draws a little air in, the lamba sensor reads the excess oxygen as meaning the engine is running lean and the ECU pumps more fuel to try and compensate.

In this case diagnosed by listening very very carefully and noticing a ticking noise. On removing the gaskets the leak was obvious.

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[integrale_evo]

Did a little reading, whipped out the jets on my carbs and found they were 115s. The twin carb alfasuds come with 130 or 135s.

As the engine is standard other than the carbs stuck on top I decided to go with 130s. A whole £12 for a set of genuine Weber ones - for my £130 a pair Chinese copy carbs

They take literally seconds to pull out the old tubes, swap the jets, then screw back in.

All of the stutters, hesitations and farts back through the carbs on part throttle transitions are gone, it drives superbly, really happy. No bogging, at any rpm, never expected it to be so good.

I still can’t quite get it to idle as smoothly and consistently as I’d ultimately like, but it’s fine. Perfectly useable. If that’s the only compromise I need to make then I’m happy!

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[Sundayjumper]

An annoying issue has cropped up on the M5. I started a new job on Monday (yay) which sadly means going to the office three days pw (boo).

Monday - went to & from work no problem. Had a Coronation Chicken sandwich for lunch.

Tuesday morning - car started fine but warned of battery discharging overnight.

Tuesday lunchtime - popped over to the other site, car was fine. I'd brought my own sandwiches: egg & bacon mayo on thick tiger bread.

Tuesday hometime - car warned of battery discharging. Got home fine. I watched the system voltage and it was rock-steady at 13.6V while driving.

Wednesday - WFH. I think it was cheese & ham. Late evening I went to get something from the car and it was DEAD. So dead that my regular charger wouldn't even recognise it as being connected. And obvs. with a dead battery I couldn't open the boot to get at it . Connected my better charger to the jump start points ion the engine bay and left it overnight.

Thursday morning - it had enough juice to open the boot, so that I could disconnect the battery and attach the charger directly.

Thursday lunch - cheese & ham again. I need to buy some more Branston Small Chunk.

Friday morning - battery still not fully charged But it's 105Ah and the charger is rated at 6A so crudely - 105/6 = 17.5h in perfect conditions so meh. Maybe 24h+ to rejuvenate and then charge isn't too far off.

Made it to work. Fish & chips for lunch ! Not amazing quality but only £2.88 in works canteen including a glass of squash.

Friday afternoon - battery discharge warning again but started OK. It was hot.

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Friday evening & today I've been investigating, monitoring the current draw. The car shuts down correctly and goes to ~200mA. Internet seems to say it's meant to be 80mA but again meh. In theory 200mA would take three weeks to kill the battery, not 24h.

BUT ! After about half an hour it was shooting up to 5-6A. And that'll definitely kill it. A sweaty process of removing fuses one-by-one today has revealed the culprit to be one or both intercooler pumps. I say one or both because they should both be controlled in parallel by the bank 1 DME but in the BMW tech document it says they're 50W each which is about 4A with the engine off but battery full charged at ~12.8V. So just one that's crapping itself independently and sucking 5A ? Or is the DME running them both at 60% ? We don't know yet.

https://www.6post.com/forums/attachment ... 1574965738

[Explosive Newt]

egg & bacon mayo on thick tiger bread.

Do you make it yourself or are we talking the pre-made stuff you buy in pots?

[mik]

When WFH I absolutely HATE having a sandwich for lunch.

Something on toast.

Or in a fresh crispy Morton’s roll.

But not a sandwich.

[Jobbo]

Sandwiches are the best lunch of all. If I have something else I crave a sandwich next day. Not the same thing as the day before. I wholeheartedly approve of SJ’s lunch choices.

Glad my M5 charges fully overnight though. And it was 27.5C at 9.00am yesterday leaving my dad’s house in Hampshire but I haven’t yet seen 40C on the display. Eek. Even our kitchen thermostats for the underfloor heating were only getting to 36C today but I think they were under-reading to be honest.

[Sundayjumper]

egg & bacon mayo on thick tiger bread.

Do you make it yourself or are we talking the pre-made stuff you buy in pots?

Home made, or home-assembled at least. It wouldn't even cross my mind to buy it in tubs tbh ! Cook some bacon, boil some eggs, chop them up & mix with mayo. Add a bit of pepper. I imagine a cardiologist doesn't recommend this as being terribly healthy though

It was actually egg & bacon mayo sarnies that finally, fully, triggered an excruciating response to gallstones a few years back. I no longer have a gallbladder.

[Explosive Newt]

It’s a good strategy, I always end up making far too much and it’s not cost effective, or not enough and I am throwing away stale bread.

Anyway why is the intercooler running at night? Surely nothing needs to be inter-cooled at that point? Or did I misunderstand?

[GG.]

Had a bit of a panic last night with the immobiliser in a Heathrow car park - the mobile reception seemed to be fine when we parked it up and I "deadlocked" it but was not playing ball last night when we got back. Following a delayed flight and sat in a hot car at 11pm with all our luggage after several attempts I gave in and called MetaTrak. Extremely helpful guy on the phone pointed out that there is an "Emergency Unblock" function that you can use that connect via bluetooth - started right up thankfully.

I then got to the barriers on exit and there must have been some IT glitch as it seemingly did not have my booking and wanted £750 on pay as you go Second saviour of the evening was the attendant who helped raise the barriers and let me through. Just hoping I don't get some automated demand for payment through the post now...

[Rich B]

I have Metatrak on my van, they are always super helpful and friendly - every time i get on the channel tunnel i get a nice call to say my van is moving without being on - made even more fun because my security question/password is very silly and makes the family laugh when i have to say it out loud (obviously im not sharing it here! )

[V8Granite]

Clio did a Clionyhing, my fancy 3d printed honeycomb exhaust rubber had made a bid for freedom, no idea where.

2 new standard ones coming in the brackets and I'll bond the fancy ones in next time when I do some underbody work over winter.

Dave!

[Sundayjumper]

Anyway why is the intercooler running at night? Surely nothing needs to be inter-cooled at that point? Or did I misunderstand?

No, you understood perfectly, there is no reason for the pump to run when the engine is off. Maybe let it run for a few minutes after switching off to dissipate a bit of heat but that's all. It also cools the engine ECUs. Totally separate from the main engine & turbo cooling system. But what's happening is that everything shuts down correctly, then about 30 mins later this pump starts up again.

Some of the details I wrote earlier turned out to be wrong. That's what happens when you believe stuff on the internet It's very important to Do Your Own Research BMW's own diagnostics & tech reference is something called ISTA and (unsurprisingly) it's excellent and highly detailed.

Pump 1 is connected to *permanent* live, and permanent earth, and controlled by ECU 1 via LIN bus, a simple single-wire communication. Being connected to perm live allows it to run the battery right down to nothing.

Pump 2 is connected to live only when the car is awake - so it can't run the battery right down. It is controlled by ECU 2 via LIN bus. A *separate* LIN bus.

So the two pumps are independent, electrically speaking. The fuse I pulled is only for pump 1. Although in the coolant circuit they work in parallel:

Screenshot 2026-07-12 140851.jpg (61.42 KiB) Viewed 165 times

Simple eh ?

"C" is the pump that's causing the problem. I need to figure out if the pump is freestyling and doing its own thing, or if the ECU (which should be fast asleep) is somehow waking up and doing something weird. I think if I swap the pumps left-to-right that will narrow it down. However it's far too bloody hot to be doing that right now.


* LIN = Local Interconnect Network

[John]

I have a small lump on my head

Something* fell from a tree as I was driving under it and hit me right on the top of my head causing a surprised yelp from me and hysterical laughter from my wife

*Shocked state rendered tree identification impossible so could have been anything from an acorn to a coconut

[DeskJockey]

egg & bacon mayo on thick tiger bread.

Do you make it yourself or are we talking the pre-made stuff you buy in pots?

Home made, or home-assembled at least. It wouldn't even cross my mind to buy it in tubs tbh ! Cook some bacon, boil some eggs, chop them up & mix with mayo. Add a bit of pepper. I imagine a cardiologist doesn't recommend this as being terribly healthy though

It was actually egg & bacon mayo sarnies that finally, fully, triggered an excruciating response to gallstones a few years back. I no longer have a gallbladder.

"Add lightness" #ColinChapman. I too am without said body part, can't say I've missed it, and have had medical professionals compliment the neatness of the scars. Not sure I can claim credit for that, but I'm happy to accept.

[Explosive Newt]

Anyway why is the intercooler running at night? Surely nothing needs to be inter-cooled at that point? Or did I misunderstand?

Simple eh ?

Bad input to the ECU seems the most easily fixable possibility.
New ECU a less happy thought.

[Sundayjumper]

I too am without said body part, can't say I've missed it...

Same. I was quite worried about it, whether I'd have to avoid oily or fatty (aka "everything that tastes good") food forever more. But I've not noticed any difference at all. Must be close to ten years now.

[Sundayjumper]

Bad input to the ECU seems the most easily fixable possibility.

True, and I didn't actually think of that, I approached it from the other direction and was thinking about ECU output in case the ECU was firing spurious signals. I totally disconnected the ECU and the pump kept running. I could even take the pump fuse in & out and it would turn on & off - i.e. it was still latched on even after resetting the power, and with no bus signal.

My working assumption is the electronics in the pump are borked and it's triggering itself. Curious that it waits ~half an hour after switching the car off to do it though. I've ordered a s/h pump to try out.

An alternative that I only thought of this morning is damaged wiring, which is quite possible as I had the engine out and might have slightly squished something. That would be annoying to track down.

New ECU a less happy thought.

For a laugh I looked up the price of a new ECU. £1,948.87 and there's two of them

https://www.sytnerstevenagebmwparts.co. ... 72239.html

[DeskJockey]

Parts prices and availability is crazy. The auto electrician I use for the Zoe has had to turn away cars because he can't source the spare parts, even on relatively new cars, and the costs for the parts he can get are eye-watering.

Last time I was there he was working on a 2022-23 Peugeot that needed some wiring replaced (known fault apparently), and a kit with five wires, two plugs, and an overall length not exceeding 10 inches, was £70+