Summer shedding BMW E93 325i SE Convertible

Summer shedding BMW E93 325i SE Convertible

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Erast Fandorin

Original Poster:

138 posts

37 months

Tuesday 20th May
quotequote all
There seems to be an appetite for stories about middle aged BMWs here so here's my effort!

Living down in the soft south, the idea of summer cruising in a soft-top is always appealing. In the past, garage occupants have included Mk 3.5 Golf cabby, MGBs, Caterhams and even a Renault 19 16v soft top. They've all shared space and time with bikes, but I was getting to the stage where the effort to get kitted up and drag the bike out from its covers (a 280kg BMW R1250GSA) meant it was being used less and less.

I'd also moved a year or so, gaining a driveway with room for a couple of cars, but losing access to a leaky old concrete garage. Added to the equation was the OH, who made it clear that wild horses would fail in any effort to get her on the back of a bike, no matter how pillion friendly.

A plan formed that involved selling the GS and replacing it with a cheap rag top, at the same time leaving a bit of money in the bank for new house stuff. Getting the spanners out wasn't really part of the plan.

So one Saturday morning last March found me in a coffee shop waiting for the OH while flicking through Autotrader, like you do.

A search for cheap cabriolets within an hours drive produced this:



Mr Tidy

26,543 posts

141 months

Tuesday 20th May
quotequote all
Welcome to middle-aged BMW straight 6 petrol ownership. thumbup

I'm currently on numbers 5 and 6 from between 2002 to 2006 and seem to be addicted!

Erast Fandorin

Original Poster:

138 posts

37 months

Wednesday 21st May
quotequote all
Thanks. I have some previous; my first car was an E3 2500 (family hand-down), I ran a E34 535i SE for a while, had a E39 520i Touring for small children duties, and one winter I smoked around in a E46 328i shed.

Mr Tidy

26,543 posts

141 months

Wednesday 21st May
quotequote all
All straight 6s too!

My current daily is a Cat N 2005 E90 330i shed.

Erast Fandorin

Original Poster:

138 posts

37 months

Friday 23rd May
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It appeared to be a tidy looking 6 pot 3 series cabriolet - the one from the era where manufacturers had all decided that a convertible should also be a hard-top - and damn the weight and complexity. But at £3,500, there had to be a catch.

Out of (very mild) interest, I called the dealer. The catch was that it had been taken in pEx by a customer who had driven down from Manchester, but no sooner had the customer driven off in their new purchase than the Engine Management Light illuminated. Hence the price. Fresh MOT though, and everything worked.

Of course, I should have run.

Eventually the OH arrived at the coffee shop. Casually, I showed the ad, and rather surprisingly she suggested going to take a look "as it's in a pretty part of the country and we have no plans today".

So I found myself heading down to the New Forest, and on the way I undertook some basic research, which included calling a family member who is in the trade. "Probably a sensor" he said. Ha!

But you know where this is going.

In the watery sunshine of an early spring day, the car looked quite presentable. It hadn't been messed with, the paint was tired, the fat (kerbed) 17" rims supported a variety of ditchfinders, and there were signs of careless previous owners (>5 of them).





On the other hand, the interior was tidy, there was no damage to the body, the roof went up and down without too much groaning, it started and ran smoothly enough when warmed up, and gears, brakes and steering were present and correct. The sparse history file (backed by the MOT read-out) suggested that 70,000 miles was genuine, the EML actually extinguished itself after a while, and the '325i' was really a '330i', but de-tuned.

But £3,230- (we haggled...) for a 6 cylinder convertible 3 series just in time for summer cruising? How bad could it be?

I handed over a card, sorted the insurance, and drove home. Which it managed just fine, showing over 40mpg for the trip.



Perfeck

Except the EML re-appeared



Erast Fandorin

Original Poster:

138 posts

37 months

Thursday 29th May
quotequote all
Working on the basis that I should try the simple stuff first, and that (unlike the fours and eights) BMW's six cylinder engines are intrinsically robust, I tried a tank of Tesco SUL fuel, a dose of treatment for petrol ('guaranteed to fix gummed up injectors'), and a reet good thrashing. An Italian tune-up is a bit of challenge; gears are long so a 2nd gear pull will take you beyond single carriage way limits.

There was some improvement; but there was still misfires from a cold start, and hesitation from tip-in, which made it easy to stall at junctions etc. The EML would still re-appear a fuel miles after I cancelled the codes.

Petrol treatment exhausted, I booked it into a local-ish specialist who has maintained MINI's and BMWs for me in the past, and asked them to give if a (post....) pre-purchase inspection and to diagnose the running issues.

Their recommendation was that the injectors were replaced, along with the rocket cover gasket.

What my pre-emptory initial research hadn't revealed is that BMW used two types of engine in the E93, pre-facelift used the simple and reliable N52 engine, but after 2007 BMW switched to a direct injection N53 motor, which hasn't been so reliable.

And injectors for the N53 are £400.

Each.

Ouch.



Erast Fandorin

Original Poster:

138 posts

37 months

Thursday 29th May
quotequote all
As the possibility of using the car for a planned trip to the Le Mans 24 hour in June receded I decided to ignore the EML and do some stuff to make myself feel better.

The complicated roof structure can go wrong, but faults can be mitigated with maintenance. Those in the know recommend Gummi Pflege rubber lubricant for the many seals between the roof sections, and Silicone spray for the myriad joints and hinges. Very satisfying.

The thin, cheap floor mats also had to go. Dredging through old emails revealed that Autostyle (still a silly name) were my go-to mat suppliers, and they're still around. A set of black with silver edge was acquired.

My eBay searches turned up a recently refurbished set of the correct Style 157 wheels, complete with a 5 year old set of barely worn Bridgestone runflats for the price of two new tyres.

One dry day I gave it proper deep clean, wash and clay, followed by a very amateur 'detail', using my cheap Amazon DA polisher.


And even found some old school polish in the back of the fridge:



Top beading:


And celebrated my labours with a photoshoot at a local landmark:


I'll admit, there were times when I was cruising along local roads on a warm evening, roof down and tunes on, when I said to myself "This is the best £3,250- I've ever spent".

Erast Fandorin

Original Poster:

138 posts

37 months

Friday 30th May
quotequote all
As if expenditure was ever going to end there......

An ABS warning light joined the Christmas display on the dashboard.

I stuck my head in the sand, and pretended a BMW with only 70,000 miles on didn't need £2400- worth of fuel injectors, and swopped in a set of coil packs and spark plugs (£160). Predictably that made no difference.

Luckily, the bike sold quickly, liberating some funds, so now it was all-in.

I needed a displacement activity so I took the boot trim out and cleaned the stains left when a PO used it to store a dead body:





Much better:




Timbo_S2

609 posts

277 months

Friday 30th May
quotequote all
enjoying the journey on this. We have a simialr E93 325i. Problems have involved a persistant EML for pressure in the cats (I suspect the exhaust has been tinkered with), and it drinks a bit of oil. Wife carries a can in the boot at all times. Other than that, its been good!

Erast Fandorin

Original Poster:

138 posts

37 months

Friday 30th May
quotequote all
I spoke to my local village garage. They were confident that a common or garden sort of middle aged BMW, which was (mostly) running & rolling wouldn’t present them with a serious technical challenge, so I asked them to sort out the ABS light (it was a n/s/r abs sensor), and the EML.

In hindsight, this was a mistake. In my defence, they often have reasonably exotic machinery on their ramps, and they are located a 5 minute walk away from my house, not a 45 minute drive like the specialist, which makes the logistics a whole lot easier to deal with.

They had the car for the best part of two weeks, during which time they spent a lot of time scratching their heads, replaced the MAP sensor, the valve cover gasket (that the specialist had suggested), and the valve cover. And then they waved the white flag, announced that it was a good as it was going to get, and sent me on my way with a £900- bill.

It was horrible; popping and chugging and generally being beastly. I drove home, parked the demonic old bd at the back of the driveway and ignored it for a month.

Clearly, I was going to have to bite the bullet and cough up for a new seat of injectors (sadly I could find no UK based enterprise able to refurbish the old ones).

I'm lucky in that I have some contacts at BMW UK, and I persuaded one to order a set of injectors using their staff discount, and I then handed the precious things over to the specialist for fitting (total bill: £1,800).



The old ones - a mix of Index 11, 6 & 7, plus a spare found in the boot. Never a good sign.



After this injection of capital was running a whole lot better, and for a short while I didn't even see the EML:



Until I did:


PS Is this peak BMW Dashboard graphics? Crystal clear, white on black, no screens and just the right amount of information in the pixels.

Note also the eccentric choice of an oil temperature, not water temperature gauge for the display binnacle.

Erast Fandorin

Original Poster:

138 posts

37 months

Wednesday 4th June
quotequote all
Should it stay or should it go?

The £3k car is already a £6k car and it’s still busted. I need to take a break from the litany of expense for some man maths.

For someone who grew up on a diet of elegant 3-series drop tops, the smooth six cylinder BMWs have always been an attractive proposition. Around my way they are still to be seen; in immaculate condition and smelling of old money and winters spent tucked away in a warm dry motor house. I’m the first to admit the somewhat bulbous E91 & 93 have little of the understated style of the E30, E36 and E46 generations (although roof and windows down they’re not bad – that beltline chrome trim is really quite slimming) , but the latter are starting to get old and the ones appearing on the market at the affordable end usually looked sad and tired.

Prettier 3 Series BMW rag-tops yesterday:

OG E30:



Elegant E36


Stylishly suave E46


Lumpen E93



The E90 series of 3s are arguably just over PEAK BMW; when electrical, mechanical and hydraulic finally gave way to electronics. While a single hump dash 3 series like mine was the last of the cars to retain the button-fest that is the trad BMW dashboard architecture, the post face lift E9Xs have largely CAN-BUS electrical systems, electrical power steering, and direct injection engines.

On the other hand, mine still has a decent 6 speed manual gearbox, a creamy smooth (and really quite economical) 3 litre engine, a manual cable handbrake, plus mod-cons like electric seats (not heated for some reason) , auto Xenon headlights, puddle lights, parking sensors, and black leather that’s wearing well. And apart from the origami metal roof, it’s frameless windows allow it to perform the pillarless window trick.



Also in the E90’s favour is sheer volume. BMW sold more than 3 million of the things over the 8 year production run, which mean spares support is very good, either used, OE, or via your friendly local BMW retailer’s parts department. Even though they’re usually hidden somewhere at the back of the showroom.

Sunk costs argument aside, where could my theoretical £6k go instead if it were limited to a 6 pot Three? The spread of E93 325/330i prices is from £5k to £9k, and from what I understand, all could need injectors at around 60-60k miles. Go up a generation starts to get expensive quickly; from 2014 the E90 became the F30 and 4 series, and a nice 435i will cost mid teens with the 440i with the B58 from £20k up.

BMW will also happily sell you a new 440i cabriolet (only with 4wd and an automatic gearbox) at a ……wait for it…really quite astonishing £70,000.

So here I am having convinced myself that even at £6k, it’s still pretty cheap thrills.

And so the expenditure goes on.

preacherman

399 posts

220 months

Wednesday 4th June
quotequote all
First up, and at a minimum, you need to get a code reader to start investigating what's causing the EML. Ideally getting INPA on an old Windows laptop as that gives you more diagnostic detail than anything else, even than the (more recent) factory ISTA software.

We could speculate what is causing the EML (NOX sensor/cat, lambda sensors, vacuum leak, DME) but without the codes and/or data it may not be accurate. I wouldn't buy any more parts until you've done that.

You'll want to get familiar with the blogs on this website: https://bimmerprofs.com/blog/. The only proper resource for the N53; I would trust this over most other material online. Your experience with the local garage is a common one. I have travelled far to Beemer specialists with great reputations but even they don't understand this niche engine. It was peak complexity and cannot be fully diagnosed without the data from INPA, which very few garages have. You'll find owners on this forum and e90 post who have INPA and have been through diagnostics journeys!

A final note, I was amazed to see that you're hitting 40+mpg with bad injectors. Ordinarily they will leak or be unable to spray a fine enough mist, preventing the engine from running in stratified mode (eco) and the fuel economy taking a hit. They would inevitably need replacing soon no doubt but the right data might have given you some breathing space on the 1800 quid!

Mr Tidy

26,543 posts

141 months

Wednesday 4th June
quotequote all
That's bad news about the injectors. frown

But one of the reasons (like HPFP issues) why when I went looking for a 330i I only ever considered for ones with the less troublesome N52 engine!

Erast Fandorin

Original Poster:

138 posts

37 months

Thursday 5th June
quotequote all
preacherman said:
First up, and at a minimum, you need to get a code reader to start investigating what's causing the EML. Ideally getting INPA on an old Windows laptop as that gives you more diagnostic detail than anything else, even than the (more recent) factory ISTA software.

We could speculate what is causing the EML (NOX sensor/cat, lambda sensors, vacuum leak, DME) but without the codes and/or data it may not be accurate. I wouldn't buy any more parts until you've done that.

You'll want to get familiar with the blogs on this website: https://bimmerprofs.com/blog/. The only proper resource for the N53; I would trust this over most other material online. Your experience with the local garage is a common one. I have travelled far to Beemer specialists with great reputations but even they don't understand this niche engine. It was peak complexity and cannot be fully diagnosed without the data from INPA, which very few garages have. You'll find owners on this forum and e90 post who have INPA and have been through diagnostics journeys!

A final note, I was amazed to see that you're hitting 40+mpg with bad injectors. Ordinarily they will leak or be unable to spray a fine enough mist, preventing the engine from running in stratified mode (eco) and the fuel economy taking a hit. They would inevitably need replacing soon no doubt but the right data might have given you some breathing space on the 1800 quid!
Many thanks for the response - definitely something to investigate. I was worried about over-fuelling when I initially bought the car, but was re-assured by the low fuel consumption - although this was a best-case very gentle ~50 mile motorway cruise.

I have found N53 specific information pretty difficult to come by, so was unaware of the INPA tool. I do have a cheap code reader; at various times it identified misfires on one cylinder (#2 ISTR), and a faulty O2 sensor. At other points it was also pointing at air leaks. The fact that there were a number of different indexed (i.e. versions) of the injectors in the car pointed at prior efforts to fix the issues.

The specialist has also been pretty good for me in the past - and sorted a friends leaky Alpina B6 - so I wanted to trust them on this. And the car was clearly running much better after the work; clearly producing more power, smooth idle and no misfires, only the rough cold starts and slight hesitation on tip-in remained.

Also, the thread is up to about September last year - there's more to come!

PS I also sold the old injectors for £100 afterwards (condition fully disclosed) so the bill was 'only' £1700 biggrin



Edited by Erast Fandorin on Thursday 5th June 10:24

Erast Fandorin

Original Poster:

138 posts

37 months

Thursday 5th June
quotequote all
Mr Tidy said:
That's bad news about the injectors. frown

But one of the reasons (like HPFP issues) why when I went looking for a 330i I only ever considered for ones with the less troublesome N52 engine!
In hindsight an excellent call!

Erast Fandorin

Original Poster:

138 posts

37 months

Monday 9th June
quotequote all
Sometime towards the end of the summer I SORN'd the car and parked it up. I had other priorities, and after servicing the roof and cleaning out the drain channels I left while I re-grouped.

The motor had improved by increments, and looked to be one last push from being resolved; although I was aware that the EML had to be extinguished for the MOT.

By way of contrast, one area I had expected to spend some money was on was the suspension - I usually end up doing so on middle-aged cars that I've bought. On collection, this one was was comically bad; it always amazes me that owners assume suspension components will last the life of a car. I recall being told once that 80% of cars go to the scrap yard with the set of dampers fitted when it was built.

The symptoms of knackered underpinnings were very obvious; if the car encounter a mid-corner ripple, the front axle would wash-out across the road. Under cornering loads, the rear axle would resist roll so far, and then just give way, leading to roll oversteer. Straight line stability was poor, minor corrections were needed constantly, there was a sense that the wheels were just bouncing up and down under the car, and larger bumps crashed and shuddered through the structure. All-in all, while cruising slowly along country roads was pleasant, there was zero enjoyment to be had in driving the car.

Over the winter the pile of boxes sitting in my study grew:



Here was one advantage of the ubiquity of the E9Xs, parts are plentiful and reasonably priced - especially if you've ever maintained a Porsche and become used to the cost of 911 spares.

I found Autodoc to be a useful source, and my local BMW Retailer was also very handy for the bits and pieces I couldn't be sure of getting right on the German company's site.

I ended up with a full front rebuild suspension kit, including drop links, top mounts and track rod ends.









The obvious replacement damper is the Bilstein B4 - usually available at around £75/corner. But after discussion with the Bilstein rep at a local event, I decided to fork out on a set of B6s. And to save the risk of flying springs; I bought some std length replacements for the front, and got the village garage to make up the struts:



The specialists had suggest £3k for the work - so far I was into parts for about £1300.

Now I just needed to work out how to get them onto the car.

Erast Fandorin

Original Poster:

138 posts

37 months

My days of spending hours under old cars are past, so I was looking for an alternative to jacks and axle stands in my driveway. Not far from me is an outfit run by a friendly bunch of Poles who will rent out a lift and tools. I booked a Saturday slot for the end of March – before the MOT was due to run out.

My youngest son (21) works in the motortrade in vehicle repairs, and a friend of his runs a sideline as a mobile mechanic. So friend was booked for the Saturday, and my two sons and me would supply unskilled labour (and in my case fund a slap up Ruby Murray in the evening).

The plan was to replace the front suspension including struts, rear dampers and the rear top links, and if there was time, replace the flexible brake hoses and refresh the brake fluid.

The day arrives, and at 9am the car was up on the lift.


Shortly afterwards #2 son arrives with the news that mobile mechanic friend had been on a bender the night before, and was hors de combat. Bugger.

After a fortifying breakfast at the local Scottish Restaurant (i.e. three double egg and bacon McMuffins), we decided to push ahead anyway. Number 2 son was a star, rolled up his sleeves and just got stuck in.

It wasn’t easy; after 16 years, many of the suspension joints had united, all exposed threads were corroded, and the things generally fought back wherever possible. Before long the BF grinder was out.


However, by 7pm in the evening, the pile of old bits had grown, new bits had replaced them, and the car was mobile again.





Rarely did a chicken Jalfrezi washed down by a Cobra taste so good.

shalmaneser

6,163 posts

209 months

Whereabout are you? Would love to rent a lift for a few hours myself!

I'm surprised you're chucking cash at the car without getting some decent diagnositics on the engine. A semi decent code reader (something like an Autel AP200) will give you tons of info. What do the fuel trims look like? Are you confident there isn't an air leak?

Mr Tidy

26,543 posts

141 months

Great work, it should drive so much better now!

josh00mac

381 posts

122 months

Yesterday (06:18)
quotequote all
Good commitment. I would love a cab for summer duties but don’t have the space. This N53 and folding hard top would scare me.

I’ve had an N52 630i for a few years - as you say this is the last era of classic BMW dash and proper steering. A 630 cab with the N52 would be a great swap if you ever move this on.

Diagnostics is a tricky one with plenty of experts. Good luck with the EML.