BMW M328i, Reassembly, Valve Cover Gasket and Dropping Things

Okay, it’s been a while since my last post, but the car has still been progressing. I left off with the exhaust on the ground waiting for exhaust gaskets, and needing to replace the valve cover gasket. The parts arrived, so I got on with it.

With the arrival of the exhaust gaskets for the manifold to center section flanges, I could refit the exhaust. This thing is a damn beast, but with some carefully juggling, wiggling and bolting, I got it back into place.

Just as a quick side note, when cleaning up under the car I noted that two of the nuts I removed from the giubo were completely wrong. That wouldn’t have helped the balance of the drive shaft.

They all got replaced, as they are Distorted Thread locking nuts. The top of them is basically squished and distorted, so when you put new nuts on, they bind on the threads and wont come loose. Reusing them is a no-no, because they will no longer bind like they should. Similar concept to Nyloc nuts, but can handle higher heat.

With the underside work done, I could finally refit the wheels with new rubber on them and lower the car down a bit and finish the work inside the car. I needed to refit the clutch pedal, as I had removed it to replace the bushes. I tried some flashy delrin bushes, but unless I removed the whole pedal box and fitted them on the bench, there was no way I could press the bushes on in the car, they were just too tight. Instead I went with a pair of new OEM bushes, slathered in grease.

Thanks to the bolt I fitted that was missing from the pedal box, and the new bushes, the clutch pedal feels much better now; it doesn’t move off the side, and I don’t hit the dead pedal now.

The other thing I wanted to do whilst under there was to replace the throttle cable, as my original one was well munted and made the throttle sticky. It was also ugly, and I don’t like ugly.

Removing the cable was easy enough, once you get the plastic clip out of the firewall (have fun one that one), it was just a case of pulling it through the engine bay and disassembling where it attached to the linkage. This is where it all kinda went wrong, all over one tiny little stupid (but crucial) bit of plastic.

As I was attaching the white plastic clip back on the end of the cable so it could attach to the linkage, I dropped it.

Of all the places, and things to drop, it was a plastic clip, between the 5th and 6th intake runners. It didn’t come out the bottom, and I couldn’t go magnet fishing because it was plastic. I tried moving and jiggling things in the area to see if it would drop down, and even lifted the car up and tried to fish around with my hand from underneath to find it. It didn’t work, I had only one option left.

The whole intake had to come off. Thankfully removing one isn’t too hard, and it’s something I had done before on my old M3, it’s just bit of a prick to get at some of the hoses and bolts.

Oh there it is, sitting on the starter motor…

This little bastard.

I then proceeded to immediately drop it again; onto the floor this time, so until it was ready to go back on, it went into my pocket.

Having the intake off did give me a chance to have a quick look around, and give the throttles a quick clean, so it wasn’t all bad. Back together it went, and on went the new throttle cable (assembling over a large rag, so I wouldn’t drop it again. See, I learn from my mistakes!).

Whilst setting up the new cable I encountered two things that made me facepalm. One, the throttle return stop had been mangled, and bent back. This stop is what stops the throttle pedal linkage going back too far when you take your foot off the pedal. If it goes back too far, there will be too much slack in the cable and you will never adjust it out. No prizes for guessing how I found this issue.

I bent it back as flat as I could, which made the pedal sit better, and allowed me to correctly adjust the cable. Being bent back was no accident; it took a lot of work to bend it forward again, so I can only suspect it was done intentionally to compensate for the stuffed cable.

The second issue, was that the throttle stop was badly adjusted. On my car because the shell was originally auto, instead of a normal solid “stop” under the pedal, I have the kickdown button still.

The throttle stop/kickdown button sits behind the pedal and is what stops you putting pedal to the metal, or more accurately, damaging the throttle cable by trying to pull it further than the throttle plate will allow. On the flip side, if it’s not adjusted enough, it will stop you getting to Wide Open Throttle (WOT).

The whole thing is on a thread and screws into the floor, but does have a locking nut that stops it goes in too far. On my car that locking nut was wound way out, which meant that the stop couldn’t be wound in as far as it needed to be, which means by the time the throttle pedal stopped, I was only seeing about 3/4″ opening, not WOT. No wonder this car felt slow!

I wound the locking nut down, and wound the stop in enough that when the kickdown button (which now does nothing but offer some nice physical feedback through my foot when pressed) is pressed, the throttle is 100% open.

With that mess cleared up, I moved out of the interior and into the engine bay for one last job for the day. The valve cover gasket.

I noticed it was BADLY leaking down the back corner, so ordered a replacement a while back. I had intended to rebuild the vanos whilst the cover was off, but decided to postpone that (for reasons I will explain in a later post) and just stop it leaking.

Replacement is easy; Remove the coils, a whole bunch of bolts, and then the cover itself. When removing the coils, you also need to move the loom out of the way, so I rest that on the strut tower.

I didn’t notice, or remember, that the coil connectors are actually numbered via a small brown plastic tag on each wire (as seen in the photo), so instead I put a small dot for each coil it went to (1 dot for coil 1, 6 for the 6th coil) with a paint pen. This is the connector for coil 2. The dots are covered by the locking clip when assembled. It never hurts to over mark things before disassembly.

And off comes the cover. It takes a lot of wiggling to get the back to clear the cable holder and the rear cam cap, but it does fit.

This is the corner that was leaking. The gasket wasnt that old, it must have been replaced when they did the head work, but for whatever reason it just didn’t seal here

The other leak I had was a bad one into a couple of the spark plug tubes, via the rubber washer on the bolts. I ordered a bunch of these (you need 20x btw, I came up two short). The old ones were hard as rocks and shorter than the new ones

I cut them all off the bolts, and pressed the new ones on. I slathered them in red rubber grease, and used a socket and a hammer to press them on. Much quick and easier than doing it by hand. Pop the new rubber washer over the threads, hold the socket on top, and give it a few good whacks with a hammer until it pops over the shoulder.

The new gasket was then fitted to the head, with a small amount of sealant in the corners of where it goes over the cam bridge in the front, and then back on the cover went. The bolts were then refitted with the new washers. Now, with the bolts be VERY careful refitting them. They are too easy to pull the threads out of the head if you over torque them. In this case I did them to 8NM working from the middle outwards and all was well

On went some new coils, and it looked like an engine again.

Some testing shows no signs of leaking anymore, which is good. The clutch pedal and throttle feel much better, with less slack and more immediate response. Unfortunately despite replacing the bushes in the shifter, there is still too much play (although FAR less than before), and it appears to be coming from the joint at the bottom of the shift lever itself, so that will need to be replaced, maybe with a short shifter?

The biggest disappointment is that despite replacing the coils and checking the spark plugs, there is still a very noticeable misfire at idle. It sounds like the old girl has some wild lumpy cams. I’m working on this now, so hopefully I can nail it soon.