mikefitz

Treat the car to a new drain/ fill plug, https://www.mlperformance.co.uk/products/genuine-bmw-e82-f10-f30-g30-differential-drain-plug-with-o-ring-inc-135i-340ix-540i-m5 Mike

Why don't you take it back to the mechanic who installed the springs and ask him to correct the issue. One common problem is tightening fixings whilst the suspension is not under load. 20 to25 mm is a big error in ride height, it needs to be sorted. Ride heights are discussed in this post. https://www.bimmerfest.com/threads/table-of-ride-heights-for-various-f10-packages.980922/ Mike

Replacement of the discharge valve, ( about £20 from Amazon) solved a similar issue on my F11. On dismantling the compressor it was clear the desiccant was over saturated. I was able to dry it out, but a kit from eBay is an alternative, complete with maintenance parts, https://www.ebay.co.uk/itm/284003906870. The air springs have been replaced with low cost Amazon items that visually seemed almost identical to the BMW units. They perform as well as the originals ( except they stay inflated) and time will be the test, OK so far after 10 k miles. Mike

Your battery is either a 95 Ah AGM type 019, or a 105 Ah AGM type 020. Top choice would be the Bosch S5 or the Varta silver dynamic, ( the same battery, different label) . Costs around £200 to £215 Inc vat and carriage for the 105 Ah battery, a bit less for the 95Ah. Another excellent battery is the Yuasa 105 Ah YBX9020 and the 95 Ah YBX9019. Yuasa batteries are available from Halfords and all the on line outlets. Tayna always seem to be competitive for batteries https://www.tayna.co.uk/car-batteries/ My guess is your battery is the 105 Ah, if not, it would be worth fitting the larger battery. Access is where you would expect a spare wheel, if your G31 is a anything like my F11. My comments are for a F11 but your vehicle should be similar. The boot floor lifts on a gas ram revealing a shallow trim cover over the remaining area. This is held in place with plastic rivets at the rear edge, use a trim tool or small screwdriver to remove these. First disconnect the negative terminal, 10mm spanner/socket, and put to one side. Remove the hold down plate, 13mm spanner/ socket, finally the positive terminal and the associated distribution panel. Replace battery and connect up in reverse order, negative last. Register the battery with Bimmercode/link, 'how to' on you tube. Don't close the tail gate with the battery disconnected. Mike

I can confirm the body length of a M sport F11 is 36 cm. Its original fit with part code matching realoem. Most aftermarket parts do not distinguish between M sports and SE. I replaced the bump stops and they were similar to the new items in your picture. From the condition of the originals, mine looked as bad as yours, I suspect the they act as an auxiliary spring as well as a bump stop. Mike

I don't think a solid flywheel conversion kit is readily available for the 4 cylinder engine. Even if available it would result in serious issues and probable engine damage. The timing chain and related parts would not react favorably to the increased shock and vibration as would the transmission. Fit a new LUK DM flywheel and clutch kit, don't even consider using the existing flywheel. A motor factor can supply the complete set of parts for around £600, Euro car parts current cost is £200 for the LUK clutch kit and £425 for the LUK DM flywheel . Unless supplied with the parts, its advisable to buy new fixings for the flywheel and clutch. The rear main seal needs inspection once the flywheel is removed and replacement needed if required. I assume the work will be DIY or via an independent. I shudder to think what BMW would charge as a new flywheel is in the region of £2000. Depending on milage you may want to consider replacing the timing chain and associated parts, kits are available. Once the gearbox is removed its possible to access the timing chain area. Watch, https://youtu.be/p_CXrfSQrIo Mike