flatsix777

Interesting thread, I never realised that there was love for them. I had an 04 645i for around a month. The valve seal issue quickly emerged & I was fortunate to be able to return it to the dealer for a refund after a little fight. I liked it a lot so replaced it with the 630i in the hope of fewer inherent issues, which proved correct. In all honesty I didn’t notice any difference in real world handling between the two; both are excellent and carry their bulk well. I imagine the weight difference is most of the reason that performance doesn’t seem markedly different from the seat once you wind them up. The V8 has more punch at low rpm whilst the 6 loves to rev at the top end, giving an impression of rather more relative urge than it perhaps has. Both sound great in their own way. Cheers David

It’s a 630i Sport with the N52 motor. I’ve had it 4 years and put 40,000 miles on it; now 130k. It’s a fantastic engine; flies at the top end and is quite rapid if you use all the rpm. It loses out to the 645i at low rpm (preceded the 630, briefly) but max attack feels quite similar. It’s planted with nicely weighted steering and a great 6 speed auto box. It feels properly refined and has a decent boot. Averages 24.7mpg in outer London and gets well into the mid 30’s on a run. Things I don’t like include run-flats, sport function that is too hardcore for a daily whereas non-sport is too soft and every maintenance task is a proper mission. They are cracking value ; mine would part-ex at around £3k I think. Insane when you think how good it is. It’s had most of the common faults, fortunately all fixed by me or else I’d be much poorer! Parts are expensive from BMW and jobs take 3 times as long as you think they should. You also need INPA software to read and code the ECUs for many tasks. Here’s the list: Starter motor - average price from ECP but the inlet manifold needs to come off. CCV - blew clouds of smoke at high rpm under load. Needs all the plastic hoses replacing that are disturbed as they go brittle and inlet manifold off. Post 2007 N52s have CCV integrated into the cam cover. Vanos Solonoids - uneven idle & just needed cleaning. Standard fault. Swimming pool in rear footwell; blocked water drains. Lots have condensation for this reason. ZF 6HP 19 box - supposedly sealed for life but, in my experience, not so. I changed the pan (plastic with integrated filter), fluid and mechatronic seals to fix a slightly hard down shift. Perfect now but the valve body needs to come out so needs commitment. The pan and lifeguard fluid are properly expensive. Wishbone bushes - all 4 arms replaced at the front at 100K. Rear shocks replaced at 100K. Oil leaks - Cam cover, oil cooler, sump. Standard and all a PITA to do. Fumes get pulled into the cabin so you have to do even minor stuff. Brake back plates - x 4. Made of alloy and corrode around fixings making a massive noise. Hydraulic lifter tick at idle - just needs bleeding every 10k, That’s the lot and everything here will affect a 630i at some point. The 645 had most of the same stuff but also, surprisingly, valve stem old seal failure. Even DIY it’s a £1500 fix and about 18 hours. I I’m a fan of them and they are a cracking motor for the money, no question. Hope this helps. David

Another pics: I’ll dig my maintenance records out and follow up - mine has pretty much had every standard issue. David

No problem; I’m a big fan too. Here’s a few current pictures: Couple more to follow. David David

Thanks Shirish, I hadn’t picked that up so great info. You’re right it’s the same 5.0 motor as in the XF and Range Rover and there is quite a lot out there on the timing chain problem when you specifically search. I’m not too sure how common it really is but will be researching carefully. The slightly earlier 4.2 XKR seems not to have this issue and still churns out 420 brake. David

I’m currently looking to replace my 630i daily driver with something that has a little more character. It’s a tough decision as the BMW does everything so well and has done its depreciating, but after 4 years it just doesn’t excite. Life is too short. I fancy a 6.0 XJS, but it’s a real struggle finding one without corrosion or welding, at least at sensible money. I love the XKR too and am taken with this 58 plate 5.0 at a local dealer. I think this is the first of the Gen 2’s (had thought that’s the 5.0 began in 2009) with a great spec and 77k miles. It’s up for £16k, so maybe is a little spendy. I can’t find anything negative in the reviews. What do you think; any experiences with them? David

Great work Les! Your experience convinces me I need to renew my injectors too. Where did you source the brass inserts (assuming similar on 930) and the injectors? You’ve done a fantastic job on the 924. Cheers David

This is a very interesting concept and it would be great to understand how it functions in use. My 930 has air intakes on the rear wings which a PO added - they have no functional purpose but a rear cooler could change all that. I fitted a Carrera matrix cooler under the front wing with fan and also a front mounted cooler where the A/C condenser used to live in order to manage temperature on track. It’s compromised but works, although heat is still marginal in the worst standing traffic when ambient temperature is high. An improved solution, using my rear air intakes, is appealing. Good work & fair play for getting on with it. Cheers David

I can’t really help with that problem but to remotely check spark I use my inductive strobe - easy to position so you can see it through the rear window. Cheers David

MoTs expiring after 30 Mar are automatically extended by 6 months now. Still got to be road worthy so brakes are a problem. Not going to help make June happen though.... David

A partial engine drop is very easy to do and gives much improved access to the rear of the case. David

Great video Jonny - excellent products. David

Fantastic work. It’s really coming along nicely and the quality is excellent. Fair play. David