In early 2012 I purchased an 87 BMW 325is (3/87 manuf.) for the purpose of racing in SpecE30. Since I don't know anything about BMWs, my plan is to drive it on the street for a few months (as well as some autocross), then take it on track in early 2013. This wiki entry contains notes on the car and build.

Engine Cooling

The coolant gauge reads low. If you let it sit for a while it'll *eventually* get almost to halfway. Hoses are warm, heater blows hot air. If you pull the temperature sensor (the left/green one) the car won't start and throws a code, so I think that sensor is fine. The aux fan hasn't ever come on, but that makes sense if the car isn't getting warm. The aux fan will come on when you hit the A/C button. I suspect that the thermostat is just stuck open.

A few threads regarding cooling fans:


The consensus seems to be that you don't need a fan at all while racing, but you need one while idling or very low speed. It seems like everybody takes the mechanical fan out and either uses the OEM aux fan or an aftermarket electronic fan.

Oxygen Sensor

The car is throwing Code 2 (O2 Sensor). I tested the signal, and it stays at about 0 volts during idle, and fluctuates between 0-1 volts as RPMs rise. Seems normal. However the resistance between the header leads is about 16ohms, which is a bit high, so the heating element may be toast. I ordered a Motronic 1.3 ECU which has better diagnostics, so we'll see if it still throws the code. BTW the Bentley manual is wrong regarding the connector pinout. I'm pretty sure that black==signal, gray==ground, and the two whites are the heating element.

New ECU says 1222, which means the car is either reading too rich or too lean. The light only comes on at idle. I need to check out the idle valve and vacuum lines at a minimum.

Slave Cylinder

What a pain in the butt. It took 7 bottles of brake fluid to bleed it. Tips:

  • The car must be level
  • Get a speed bleeder (SB6100), as the normal screw fits very loose and lets air in. Or use some thread sealant.
  • If you still can't get all the air out, pull the slave cylinder off the car, but leave the hydraulic line attached. Pump the plunger a few times and reinstall.

Charcoal Canister

Build Log

I realize now that I should have started this log earlier. So the beginning of the build isn't documented. Fortunately/unfortunately I haven't done that much.

Replacing timing belt (?)
Replaced water pump (?)
Replaced some coolant hoses
Replaced spark plugs (?)
Replaced distributor cap and rotor

Replaced front springs and shocks
Replaced front control arms
Replaced front hubs
Replaced from control arm bushings with offset delrin ones

Cleaned injectors in ultrasonic cleaner and other chems.
Rebuilt injectors (o-rings, pintile caps from mr injector)
Reinstalled injectors, bolted down intake manifold

Removed coolant hoses from heater core. Plugged hose at rear of engine with a splice and cap. Plugged hose at thermostat with splice and cap.
Throttle body coolant bypass. Removed hoses from throttle body. Capped hose on thermostat (down the road I should press out the fitting in the thermostat and thread in a plug. In progress of finding a bolt to plug the threaded hole in the side of the block.
Removed charcoal canister. Put fuel filter on end of fuel line. Need to do something better later to make sure fuel doesn't come out during rollover. Also need to remove solenoid and plug vacuum line.

cars/spece30.txt · Last modified: 2015/08/04 08:12 by justinhomi
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