1986 BMW 325E

Earlier this year my father, brother and I decided to take a look at a 86' BMW 325E 5-Speed Coupe for sale close to us. 

The car was non running/driving so it had to be towed to our driveway.

After taking out some of the interior more rust became apparent:

Passenger side rear subframe mount:

Drivers side:

Trunk:

Passenger side firewall:

The floor was surprisingly clean considering the condition of the rest of the car, but the worst area by far was the driver side frame rail, which was all but gone. This E30 will need plenty of welding down the line to be road worthy. 

But before that we want to see if we can get the motor to run. 

If we can get it running and driving reliably, it should make a pretty fun weekend beater. 

Welcome, not to be too nosy but what part of Ontario are you in? 

Looks like a fun project, good luck on getting it going. Make sure that timing belt is in okay condition before running it too much.

In reply to adam525i :

No worries! We're in Vaughan, already got new belts to put on when the weather gets warmer.

Neat. Yeah, that should be a pretty fun weekend car.

Good luck with the repairs. 

Looks like a fun project. I have several e30s and they demand attention.

If you haven't sourced them already I've used Valcas Garage for several patch panels. Shipping can take a minute because they're over in europe I think but the parts looks robust.

Definitely second the timing belt. I wouldn't do much more than hand crank it until you've swapped that.

I'll be chopping up an E30 to go to scrap in the coming months, so let me know if you have need for any cutoffs. 

In reply to KevinLG :

Yeah, I'm interested mainly in the floors and the metal behind the rear mudguards, here's what ours looks like under the carpet

If your car is cleaner in these areas please do send some photos, thanks!

Unfortunately all that rust at the front of the footwells is where all of these cars rust. You'll find a lot of the rust spots are where the studs holding the insulation panels underneath are welded on. Fortunately most of that stuff is fairly easy to make out of sheet metal, though you'll have to make that rocker corner in multiple pieces to weld together. I just did the same thing last year on my '86 325es, it was externally a fairly rust free car but the floors were at least as bad as yours.

If you've not done repairs like this before, the lessons that took me the longest to learn were one - cut back to clean metal, even if it means the holes get really big and the fabrication is harder. Welding to thin half-rusted metal doesn't go well, and even if you get it tied together, it won't last long since it's already compromised. And two - spend the time to make the patch panels fit tightly. Makes the welding and finishing part so much easier, but it is so tempting to cut those corners when you're in the middle of it.

EP 1: Starting the rust bucket

All we need if fuel and spark, simple right? Not really.

After sending 12v to the in tank pump and the 2nd pump, only the first pump made noise, which is supposedly enough to get the engine running.

The E30's fuel lines were rotted out almost completely, so we ran temporary rubber lines, one from the pump to the fuel rail and the other from the return to a empty container to catch returning fuel.

Now turning over the car actually pumped fuel to the engine but still no start. Next we replaced the plugs, distributor cap and rotor with new parts.

Old Cap:

New Cap:

Now the car would turn over, but only run super rough on a what sounded like 1 or 2 cylinders.

Maybe faulty wires? Checking each plug for spark while cranking the car disproved this, showing spark on every plug.

After some more research we decided to check the crank reference and position sensors:

Doing a quick resistance test, both sensors readings where within those specified in the Bentley service manual. Then we checked the wiring from the sensors to the ecu connector with a multimeter, it was fine. 

The last thing we could think of was an ECU issue, so we took that out, opened it up and found no water ingress or anything noteworthy. At this point we were stumped because we had fuel and spark but the car would not run. 

Checked the compression on each cylinder, as well as fuel pressure at the rail, everything was in spec.

Finally we decided to try swapping out the old ignition coil with a newer one we had lying around, and to our surprise, the car fired up and ran perfectly.  What was happening is that the old coil was working, but just barely, outputting enough power to create a spark but not a strong one, thus not igniting the fuel in every cylinder.

Now the e30 runs!

What the setup looks like:

Obviously this solution is temporary just to see if the car could run, next post will detail overhauling the fuel system.