Part No. 7790701

I had already planned to sell the car, when the “Intake manifold with flap control” was found leaky during the regular inspection. Good thing I had already taken a seat, when BMW gave me the quotation on a new manifold and a set of new glow plugs.

The car was ten years old and had done ~ 180000 kilometers, so this was not suited to current market value. And apart from spending 2 k€ on a car I was going to sell soon anyway I was annoyed by the throwaway mentality. Scrapping that amount of parts was not an option.

On the driver’s side of the engine block the dirt could be seen even without a flashlight. This is a blindfold foto from the underside of the manifold. It shows the swirl flap actuator bar. The dirt comes from there.


Swirl flaps are a familiar source of hassle. In the old engines the metal flaps occasionally fell into the cylinder and ruined the piston. My 535d had the newer version, which does not kill the engine, but will cause leaks over time. And many of the Diesel engines have this problem – not just the top-of-the-range M57TÜD30 TOP.

The manifold could surely be repaired, but the swirl flaps can’t be purchased seperately. The good news is: you don’t need them. The engine may run a bit more smoothely under low load conditions and your emissions and efficiency may be slightly better, but in real life you won’t notice the difference (at least I didn’t). And you can order blanks to seal the holes caused by completely removing the worn out flaps.

After reading the excellent pictorial instructions at (big THANKS, Peter10654!) I felt confident that I coud do this. Supplementary to this kind of tutorial the BMW “TIS” should be consulted – especially to get the proper torque values for the screws!

As there is enough plastic built-in I bought the ceaper version of the blanks (not the metal ones). And I took both versions (and re-sold the smaller 22mm blanks later). You need a bunch of seals and not every one is included in every package. Mind the exhaust gas recirculation and the throttle valve (yes, it’s a Diesel and yes, it has a throttle valve nevertheless).

Like Peter10654 I also had to change the glow plugs (and the controller powering them) and I procured some air filters (engine and interior) and the breather. It had to remain the cyclonic separation unit, as “PuMA measure 19196848” did not apply to my engine.

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Luckily I could use another car and the associated garage for two weeks, so I could work on the disassembled BMW in the evenings. The garage had an oil separator, but I had no idea how much dirt was waiting on the panels under the engine. Better be careful with this…

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Taking out the fuses powering the preheating unit and the ECU was the least I could do before unplugging everything there.

Not only the acoustic covering and the interior air filters, but also the strut brace was in the way. No big deal.

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There is the manifold. Now the dipstick can be unscrewed and the electrical and pneumatic connectors unplugged.

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It is always a good idea to have a magnetic gripper at your disposal. When in doubt put it next to the socket before completely unscrewing the nut.

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Loosening the manifold. Throttle valve and EGR have to be taken off afterwards. Then the manifold can be detached completely.

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To get rid of the oil from the breather, coking from the EGR and the other nasty stuff I brought a viscous machine cleaner. Brake cleaner from a spray can then blasts away the dissolved mess.

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Time to change the glow plugs. This was the most critical part: if the threads are too tight and you overtighten the hex you are finished here! The core of the plugs can hardly be drilled out – electrical discharge machining (after removing the cylinder head) is a realistic option then. But for me everything went well. 🙂

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With the threads cleaned (brake cleaner evaporates -hopefully- quickly enough, so nothing drips into the cylinder) and the new plugs inserted I could start to work on the dirt.

The upper part of the block was clean enough already, so I could exchange the preheating control unit. This is really difficult, as about everything in the motor compartment, not just the coolant hose, is in your way. And you have to unlock the sealed connector blindly.

Remember to push it towards the case first, to release any jammed latching.

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The manifold can be taken apart seperately. Detach the EGR- and throttle valves, throw away the old seals and demount the bar actuating the swirl flaps and then the flaps themselves. The easiest thing to clean should be the manifold pressure sensor, which can just be pulled out.

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Cleaning exhaust gas recirculation (could be rendered harmless in the E39, but not anymore in the E60 – unless you fiddle with the software…) and throttle. Not as spick and span as Peter10654 did it – but this was at the end of ownership, not the beginning. 😉

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Same with the air ducts:

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And now: the blanks. I already tried penetrating oil for cleaning – it also lubricates the viton seals.

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Re-attaching EGR and throttle:

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Before re-installing the manifold I changed the breather. Assembly is self-explaining / poka-yoke.

But why did they use plastic bolts with external torx heads?! If they had used them for the strut brace it would have made sense: the vehicle front end is made from aluminium and if you overtwist screws there you have a serious problem, but just to attach some cable holder, that gets in your way… -.-


I could borrow the “E6” socket, but if you can’t maybe “Neji-Saurus” is a better purchase.

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Afterwards the counterparts of the manifold seals could be cleaned and the intake manifold re-installed.

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Big question now: error codes or -messages? Of course. But it could have been worse than “increased battery drain”.

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The engine started. 🙂 So I re-installed the strut brace (MIND YOUR TORQUE HERE!!) and put the rest back together along with changing the air filters.


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As a memento I cleaned and lacquered one of the swirl flaps.


A nice addition to my collection of failed car stuff already containing a razed gear from a Volvo V40’s (Renault-made) gearbox and my color mixing light guide / badge lamp.


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