OM651 Inlet manifold - replacement options - genuine/pattern/oem?

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New Member
Jun 12, 2017
S212 E250 Sport Estate
Long time member/lurker. Had my 2011 E250 CDI parked up for about 2 years now, went into limp mode just before lock down and I've been into the office about 10 times in 2 years so just use the old land rover as I was 99% sure I knew what it was and I was no looking forward to tackling it. Sure enough i have never had to remove so much on a car to get to one part, but I am almost there and sure enough there is a nice leak down the back so either a crack or broken bolt. I also found an EGR leak due to a missing bolt resulting in a gasket being eroded away.

It is getting a complete EGR/inlet strip down clean out and replacement of every seal and gasket I can get to and a new inlet manifold and another fuel filter housing (spotted damage). I spotted what I thought was a good deal on a genuine, new inlet manifold that was listed as being "without flap actuator" and ordered it along with all genuine gaskets and o rings from Mercedes dealers. Sadly when it arrived today, despite being the same part number, it is a non-swirl flap version - I was intending to reuse my actuator and save £250.

I was quite surprised to see so many non-genuine versions on the usual European parts sites but wondered if anyone had experience with ones from brands such as Febi Bilstein (£100) or Pierburg (£216)? Anyone know who makes them for Mercedes or compared one of the non-genuine ones? I find it hard to believe that anyone would go to the expense of making injection moulding tooling for such a complex part. I normally buy genuine parts and filters unless I am sure it is the same company who makes them for Mercedes.
No experience of these but Febi and Pierburg are well known names; I would be very surprised if the Pierburg one is not as good as the OEM one - may even be OEM.
You may find that a third party developed the tooling and then sold the tooling to multiple different manufacturers - the world wide demand for these manifolds must mean that there is a decent market size. So it maybe that the Febi branded one came from the same tooling as an unknown brand. I've had mixed experiences with Febi parts - I would go for the Pierburg if it was my car.
I have recently completed this. There was a snapped bolt, usual one 2nd from the front at the bottom. Happened when I hit a double bump on a country road, rushing to showjumping one Sunday morning.
I used the...the.. cant remember Pierburg or Febi, but anyway not a Mercedes one. I examined it and I could not find any difference in the moulding, design or quality. I even weighed it, after cleaning the old one and allowing for the broken bolt. No perceptible difference. I even noticed a small mould number that was the same as the Original Mercedes one. You can be sure that they are all coming from the same source.

I also replaced the Diesel Filter heater/housing for the upgraded one with the three bolt holes-Mercedes Original, sourced from Germany. I even replaced the thermostat again Mercedes Original.. Renewed all the seals -Mercedes original. Cleaned everything including EGR, throttle body etc. £150.00 approx for everything.

Oil now after 500 miles is as clean as a petrol car and manifold is working perfectly,. but one day at a time

I would have been delighted to have sourced a manifold without the flaps
Coming back to this, work, farming and little ones got in the way. Can get a genuine one with new motor for £360 until tomorrow night (10% off on ebay) or the Pierburg for about £200 so, given the responses above I think I will go the latter and hope the actuator is fine. Given I had a code for flaps not returning I suspect the mechanism is all gummed up and possibly worn. I had thought about fitting the flap-less one but I guess I will just get an error code? Unless I fit the actutor and just let it do it's thing? I assume the flaps must do something useful at the low rev range?

I already have a new filter housing fitted by a local specialist when I got the car but on removal I noticed that one of the hose connections has a bit of damage - looks like someone was too rough with it and by the time I buy (if they do it) a new seal I just got a new genuine one for £30 something, got a whole set of EGR gaskets (OEM) as well and a new throttle valve o-ring.

My leaking EGR made the insulation on the bulkhead very fragile and it has a hole in it, whole part is £60 metal and insulation so that will solve the common annoyance of the insulation sagging away along the top. I wonder if I have been losing boost through the leak. tbh the power for a 2.1 litre has always impressed me at how much it could shift such a big car and I would regularly get 58-60mpg on a run. Bristols impending LEZ has me wondering about replacing it with something Euro 6 but I rarely go into the city.

My tip for anyone doing this - get a very long reach 10mm spanner for the bulkhead nuts.

Thanks again for the replies
The OM651 engine is fitted to multiple vehicles- longitudinally and transversely-cars and commercial vehicles- different world markets--differing states of tune---single/twin turbo versions----its no wonder there are different variations of inlet manifold- which will fit!
chassis/engine no is your best guide to duplicate exactly.

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