BMW E30 Firewall Rust Inspection + Bulkhead Wiring & Engine Bay Strip Down | 028

BMW E30 Firewall Rust Inspection + Bulkhead Wiring & Engine Bay Strip Down | 028

In this BMW E30 build video I finish stripping out the engine bay following the previous M40 engine removal and also remove the sound deadening and heat shielding on the bulkhead or firewall to inspect it for rust or damage.

I started off by unhooking the battery and removing it, then zeroing in on all the wiring which is routed around the front of the car, with all of this unhooked you end up with two bundles, one from the driver's side and one from the passenger side through the firewall of the E30.

The wiring also crosses the bulkhead tidied behind a plastic cover to keep it neat, I removed this entirely and separated the wiring.

With this out of the way I removed the windscreen washer fluid bottle and the coil pack, along with removing the bonnet or hood latch from the front core support.

I finally removed the exhaust from the car, which was now only connected via the mid hanger and rear backbox exhaust hangers.

I also took the opportunity to remove the propshaft by disconnecting the centre support bearing and removing it from the diff.

At this point, I decided to try and drop the subframe with the steering rack and power steering pump etc still connected to it. First things first was to strip off the nice new HSD coilovers I fitted in a recent episode along with the new brakes.

Then I loosened the front subframe bolts and attempted to lower it down carefully on a jack. Needless to say, I came clattering down to the ground after a few taps on the steering linkage which was holding the whole thing up. Luckily no damage.

I was unable to figure out how to remove the fuse box, but there's clearly a large bundle of wiring passing just behind that into the cabin.

Knowing that I also needed to access the back side of the brake booster or servo, I headed into the car to dismantle the glovebox and see what was hidden behind it.

Unfortunately, there's no big connector to remove to take that fusebox out, so I will be leaving that for now and coming back to it.

But while I was in there I removed the 4 nuts holding the brake servo in place and also disconnected the clevis pin which connects to the linkage (and in turn the pedal).

Back on the outside of the car, I proceeded to disconnect the 3 brake lines connecting to the servo and in standard fashion, got brake fluid everywhere before managing to remove the servo altogether. A good tip here is to make sure you drain the master cylinder before unhooking those lines.

While I was dealing with a mess I also removed the clutch slave cylinder and drained the fluid from it.

With this out of the way, I disconnected the hard brake lines from their white plastic clips and removed them from the engine bay for safe keeping, and then

With all this removed, I could finally start removing the sound deadening and heat shielding which covers almost the entirety of the bulkhead, to reveal what rusty horror may lie underneath.

Knowing the firewall is a very common spot for rust, I was expecting to find some terrible spots under here. A really common one is the whole that the steering shaft pokes through, the foam deadening here can soak up water which allows corrosion to occur, and that rust can spread far and wide. Another common spot is below the heater matrix hole, and also below the brake servo hole, plus around the heater box where the blower motor is.

The worst I found was that the blower motor area was full of leaves and the drain blocked entirely. But other than that no rust in sight. I can't believe my luck on this one.

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