Rebuilding a BMW intake: S52 to M50 manifold conversion, day 1

◷ 3 minutes to read   ⁓   Next post →

Coming to you live from my parents garage in this 7 part series, are the chronicled adventures my dad and myself had converting an S52 intake manifold to the larger M50 intake manifold. Day 1    Day 2    Day 3    Day 4    Day 5    Day 6    List of parts    Day 7

Today, Saturday was the first day to installing this kit–something that should only take 2-3 hours or so, well based on what the directions tell you (they are wrong unless you’ve done this 35353 times, have direct access to OEM BMW parts, and can understand these horrible directions).

Taking the S52 manifold out was a bit of pain. The directions are not clear at all about what is connected to what and the pictures are pretty bad. Luckily the Bentley manual is much clearer. Additionally, 101 Performance Projects for Your 3 Series has fantastic color photos and instructions that helped a great deal as well (see project 12).

The most troublesome issue about taking everything apart was dropping fasteners! Many of the bolts and nuts and so forth and very hard to reach and only one hand can squeeze in there, this leads to trouble once the bolt is lose but there is no way to catch it. This was particular troublesome with the 7 bolts holding the manifold down. Having magnetic tools would helped a lot, or a tool like this. Or duct tape on a stick can work wonders too ;-)

One note the instructions don’t tell you is that the fuel injector heads are extremely delicate–we accidently broke a few small pieces off of them, but luckily the tips were perfectly fine still.

About 4 hours later, we had everything apart :-)

With everything apart it was much clearer that I could buy a couple more hoses (heater & coolant ones) and figured might as well order those less I have to take the manifold off again anytime soon :-)

Since that was the decision and I knew I wasn’t putting everything back on, I decided to focus on a few other little projects I was going to do with the manifold off.

First up, I replaced the VANOS oil line and solenoid (project 18 in 101 Performance Projects), that was a snap to replace those—a snap, but certainly not cheap, coming in at over $200 for both parts, doh!

Next up was replacing the knock sensors. Something that isn’t clear anywhere is that there are 2 knock sensors but it is a single piece. So I bought 2 knock sensors, which I thought I needed, but that turned out to be 4 sensors in total, doh! Thankfully I could return that extra set :-)

And last up was replacing the valve cover gasket. While this could be done with the intake manifold on, it was a bit easier with everything apart. Everything was going great till I started to put it back together. The bolts holding the cover down were to be torqued to a low 10 N-m. Well I set the torque wrench to this and started tightening and then snap – it broke, my first over torqued screw (seems the torque wrench needs a re-calibration too). So I had to take it all apart to get the broken stud out (luckily it was easy to get out), but doh indeed!

12 hours later, it was nearing 10pm; what a long day! Everything else will have till next weekend…

Tips from Day 1:


Read this next:

Rebuilding a BMW intake: S52 to M50 manifold conversion, day 2 →