Troubleshooting Gearbox, Engine Oil, and BMW Bargains

“Andrew Everett looks at gearbox swaps, N43 engine oil pressure, and some used BMW bargains – including some tasty 4 Series tips…” 

Diesel Gearbox Swap

Troubleshooting Gearbox, Engine Oil, and BMW BargainsIt’s quite well known in the trade that the post 2009 six-speed manual gearbox – the ZF GS6 45DZ – is a bit iffy. It works fi ne when it works but it seems quite prone to synchro failure. Whilst there are a few aftermarket parts to repair these it’s still an expensive job and about the same as the $594 a used box will cost. These were fitted to the 1, 3 and 5 Series with the N47 2-liter diesel from 2010 onwards, starting with the F10 520d – so a huge number of cars. Lower powered cars such as the 118d and the like tend not to have them.

Non-Efficient Dynamics cars have a cheaper escape route. The older 2007-2009 GS6 37DZ ‘box is both physically identical and, at around $170, a hell of a lot cheaper. As long as it has the stop/start switch on top of the box (a small plastic control unit) then you are good to go. The only trouble is, you will find that your cruise control then won’t work and you may fi nd performance a bit different. That’s because the ratios are different and the engine ECU will detect that the engine speed to road speed isn’t correct and flag-up a fault code. However, that’s easily and cheaply fixed – your car has a diff ratio of 3.15:1 and the one you need is 2.56:1. You’ll buy the correct diff for well under $85 and fitting it is not much more than an hour’s labour.

That’s all well and good on the regular 1 and 3 Series cars but on F10 520d and Efficient Dynamics cars you’re going to struggle. Efficient Dynamics cars will need the gearbox, diff and a standard 120d/320d ECU so it’s starting to become complicated and expensive. The 520d manual has a 3.38 diff ratio and apart from the 3.08 and 2.93 units fitted to autos, there’s no alternative as the previous E60 diff certainly won’t fi t. If you could live without cruise control then the 37DZ box will fi t and work and you may find a 2.93 auto differential will reduce the gearbox to road wheel speed enough for the ECU to be content again but I don’t know if it’s been tried yet. It might work, it might not. Certainly, as early F10 520ds are down to £4000 and still dropping, and a 520d auto diff is worth about 100 quid, it’s an option worth looking into.

Read :   Troubleshooting Viscous Fan BMW Problems

N43 Oil Pressure (again!)

The poor old N43 has been much maligned, but not nearly enough. Recently I’ve heard of a couple of these engines with flickering oil pressure lights at idle. One was in a 2008 320i and another in a 2009 118i. In both cases the sump was dropped and inspected for bits of timing chain guide that have been sucked up into the oil pick up pipe – nothing was found.

However, it was found that when going through diagnostics, the oil temperature was almost reaching an astonishing 120 degrees – that’s bloody hot for old oil. The reason this was happening is because the mapped thermostat these engines have wasn’t doing it’s job well enough and that was leading to the coolant running very hot also.

N43s are supposed to run quite hot for emissions but if you cook the engine, it’s going to go wrong. In both cases, the thermostat was replaced with a new genuine item and once the oil and filter were replaced the problem was solved. So if if you have one of these, it’s worth getting the engine up to temp and letting it idle for 20-minutes with the cooling fan cutting in and out – and checking the oil temperature with diagnostics. It might just save you the nightmare of an N43 engine swap or rebuild.

4 Series Bargains

Well, the new 4 Series Coupé is out and whilst it’s not ghastly like the 2 Series GC, its styling is best described as ‘challenging’, but even as stick-in-the-mud as I am, I’m confident that we’ll be used to it in six months. Think back to the shock of the first 1 Series 16-years ago and how modern the Bangle-era cars still look today. The 4 Series will drive every bit as well as the new 3 Series which means it’s as good as you get.

Read :   Review BMW M4 CS For Work And Touring

It’s worth having another glance at the outgoing F32 model. Launched seven years ago, I managed to blag a 428i M Sport for a road test and thought at the time that it was near enough the perfect everyday car and a worthwhile improvement on the outgoing 3 Series Coupé – itself a fine drive and very easy on the eye.

F32 production has now ended which means there are astonishing bargains to be had, especially on ultra late pre-registered cars and ex-demos. Having a dealer’s name on the V5 won’t really affect resale on what is now an old model but we think good specification late model F32s could be holding their value better than expected after the initial hit.

Choices? The turbo sixes are great of course but I thought the 428i with 245hp was superb and the replacement 430i even more so.
They are not as good on fuel as the 420d but they’re good enough and have a lot of poke. Right now it is bargain city at BMW dealers: how about a 69-plate 435d X Drive M Sport with thirteen miles (yes, 13) for $27145? An equally fresh 420d X Drive M Sport, same nominal mileage – just $21207. My favorite though, a February 2020 (so new…) 430i Auto M Sport, rear drive only, next to no mileage and a fiver under $22900. This is new 1 Series cash for one of BMW’s best ever styling efforts – so lovely to drive and own.
Go and buy one, and let us know how good a deal you got.

Used BMW Bargains

‘Why pay more’ is such a good slogan and it’s rarely more applicable to used cars. Covid-19 has hit car makers very hard and the expected huge job losses are going to make a new car about the last thing on folk’s minds. Time to kick that $340 a month PCP into touch and buy a cheap used car – but not a bad one.

Read :   Troubleshooting BMW E34 5 Series Common Problems

Skimming through Auto Trader looking for inspiration found me a clean one-owner E60 525i manual. It was Gloss Black with Dark Grey leather and the skinny standard 16-inch wheels that children used to point at and laugh – but it had done a real 110,000-miles, had two keys, the full book pack and had just had a new set of tyres – £1950 to you Sir/Madam, and I bet £1800 would buy it on a good day. The E60 has had a slightly rough ride (mainly from E39 adherents) but a good example is still a fine car. Its ride and handling on the 16- inch wheels is probably not far behind the current G60 model due to its lighter weight and good old hydraulic power steering and, with the old M54 2.5 engine on board plus the six-speed manual, it will be a tough and reliable old thing. For under £2,000 here is a nice straight-six petrol BMW to last you ten years. The other side of the £2000 E60 coin is the much newer 57-plate 525d M Sport Auto with the ‘slight flaring from second to third’. There’s nothing ‘slight’ about it, it’s finished and needs a rebuild in the way every ‘slight’ problem is in fact a mechanical disaster. Unfashionable is always the way to go with bargain motoring.

Beggars can’t be choosers of course but in these uncertain times they’ll find a really decent car for a couple of grand if they’re canny and swerve all the ‘just needs XYZ’ scrap and this 525i shows just what is out there  .

Leave a Comment