Repairing the VANOS seals on BMW’s M52TU/M54/M56 engines

Since 1992, BMW has used a variable valve timing unit, called VANOS (an abbreviation for the German, variable Nockenwellensteuerung), which advances or retards the timing based on readings from the ECU in order to optimise performance. Initially, a single VANOS setup adjusted only the intake timing, but BMW introduced a double VANOS setup in 1996 to adjust both intake and exhaust timing. The unit sits at the front of the cylinder head, and the readings from the ECU send a signal to the VANOS solenoid, which then adjusts oil pressure to operate two pistons inside the unit. The pistons in turn adjust the timing by advancing or retarding the camshafts. Continue reading “Repairing the VANOS seals on BMW’s M52TU/M54/M56 engines”

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SEAT Leon (Mk1) front suspension overhaul

Next to your engine and gearbox, maintaining your suspension is one of the best things you can do for your car. The suspension is both what keeps you connected to the road, and what absorbs all the road’s imperfections, and in a bad state of repair, it will hurt your fuel economy, decrease the lifespan of your tyres, and adversely affect your car’s ride and handling, not to mention make your car less safe to operate.

Thankfully, rebuilding a suspension on many cars is not a terribly expensive or exceedingly difficult undertaking, and doing so can make a tired old car feel much newer again. It is also a job that can quite often be done an average DIY-er.

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Continue reading “SEAT Leon (Mk1) front suspension overhaul”

How to cripple your engine in one simple step

Vacuum leaks can be notoriously difficult to diagnose, as they can range from small cracks in a hose or intake pipe, to a clogged crankcase vent system, to an improperly sealed oil filler cap. This is largely the reason I have ignored my E39’s minor leak, because diagnosing it would mean removing the whole air intake system to check everything over. Plus, barring an occasional stumble at idle, the car seemed to run fine. However, last week, when it started tripping the check engine light and logging fuel trim codes, I decided it was time to sort it out. Continue reading “How to cripple your engine in one simple step”

Restoring hazed and oxidised headlights

Last month I replaced the aftermarket headlights on my E39 with OEM units. Since I had purchased these used, they had some of the usual hazing and oxidation on the lenses.

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So, arming myself with this excellent tutorial, some sandpaper, and a spray can of clear coat, I removed the headlights from the car – a very easy thing to do on the E39’s – and set to work. Continue reading “Restoring hazed and oxidised headlights”

Overhauling the rear suspension on an E39 saloon

There is no definitive answer for how long a suspension component should last, but when your car regularly deals with rough roads, road salt, and other stressors, it is no surprise to find parts beginning to wear out around 50,000 miles. I bought my E39 in the autumn of 2015 with 54,000 miles on the clock, and it needed new tie rods up front. Since I had it apart, I also did the traction arms, control arms, and anti-roll bar links at the same time. A couple of months ago, at 68,000 miles, I replaced one of the rear strut and coil assemblies, and noticed at that point a split boot on the rear control arm. A creaking sound from the nearside rear also indicated a bad ball joint, which you can see below.

Continue reading “Overhauling the rear suspension on an E39 saloon”

Lighting the road like it’s 1999

I bought my E39 for a variety of different reasons, but its headlamps were not one of them. The previous owner had fitted some imitation ‘angel eyes’ that he found on eBay, which, while providing good light, did not look very nice. It was particularly when looking at them from the side that you noticed how cheap they looked (despite costing about the same as a proper facelift set).

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For quite a while, I left them alone. After all, they worked, they passed MOT, and I couldn’t find an OEM set for under £200. If I was going to replace the lights, it would have to be done cheaply. Patience was rewarded, however – a few months ago, I found a pre-facelift set off a breaking E39 for £50. They needed to be rebuilt, as they were missing a couple seals and the adjusters were broken (a typical problem on the E39), but they were complete and clean. A few quid for new adjusters, a helpful tutorial from YouTube, and a quiet Friday night in front of the TV, and I was in business. Continue reading “Lighting the road like it’s 1999”

Rebuilding a propshaft on a BMW E39

In my previous post, I mentioned that I wouldn’t be doing any more work on the E39 until after Easter. I really shouldn’t say things like that, because yesterday I found myself underneath the car again.

Very soon after I bought the car, I became aware that the centre support bearing on the propshaft was on its way out. The initial clue was an occasional pinging (metal to metal) sound when I set off from a stop. It wasn’t something that needed to be done right at that point, though, as there were no other symptoms and everything was smooth. But in recent months, the pinging has gotten worse (it has been doing it all the way up through third gear), and I noticed increasing slack in the driveline and some minor vibration, particularly at higher speeds. A day off had been marked in my diary, so I decided it was time to rebuild the propshaft. Continue reading “Rebuilding a propshaft on a BMW E39”

Replacing the rear struts and coils on a BMW E39

A week or so ago, I started to notice a rattle coming from the rear end of my E39. I knew I had a few things loose in the boot, so initially suspected it was just something back there moving around. However, after tidying things up, the noise persisted, and the other day I got underneath the car to see if something like a sway bar link had broken. To my surprise, I discovered this.

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I had no idea the coil was in such poor condition. There was no mention of anything when I had it MOT’d in July, and when I most recently inspected it, probably in early autumn, it looked fine, save for some of the coating flaking off. On top of all this, I hadn’t noticed any difference in how the car drove. Continue reading “Replacing the rear struts and coils on a BMW E39”

Replacing the door seals on a Mk1 Leon

Several months ago, I noticed that the front footwells in the Leon were quite wet, and began tearing the interior apart to figure out where the water was coming from. Part of the problem was a perished seal on the pollen filter housing, allowing water to come in through the fan housing. This was made worse by the fact that the drain passages on the inside of the wing were blocked.

However, the bigger problem, and main source of the water, was that the door seals were perished. It is very common for the door seals to rot on Mk1 Leon’s, so it was not difficult to find an online guide to aid with replacing them. I used this guide, and found the whole job to be simple and straightforward as a result. Continue reading “Replacing the door seals on a Mk1 Leon”

Would you trust the Mini Lift 2500?

If you work on your own car, you will have a way to get it up in the air. Most backyard mechanics or DIYers will use the traditional jack and jack stand method. It takes a bit of time, but it’s proven and reliable. If you’ve got more space and more money to play with, you might have a pit in your garage, or even a hydraulic lift.

Today I came across something called the Mini Lift 2500, which seems to slot somewhere in between the jack stand and hydraulic lift methods. It’s a collapsable lift that slides underneath your car, and then with the aid of a crank, lifts the whole of your car up to a maximum height of 585mm. Continue reading “Would you trust the Mini Lift 2500?”