This article serves to provide nuanced detail for those looking to refresh their OEM setup (Denso with early style dryer in particular); one of the biggest roadblocks is that the OEM parts catalogue (ETK) is often wrong. Also, reference to this article for how to recharge the AC system: How to recharge the AC...
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When changing the AC evaporator on a BMW E30, there’s definitely a right and a wrong way to do it. The glovebox is attached to the car by a brass-colored piano bracket. If you remove the black screws, you’re going to spend a lot of time realigning the glovebox when reinstalling. Instead, if you...
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There is only one correct way to test an E30 AFM, and that’s by using an oscilloscope. The most common mode of failure is the wearing of the carbon strip within the AFM. In simple terms, the AFM is one big variable resistor. It takes a +5V supply, and the carbon strip provides variable...
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Perhaps one of the least understood components on the E30 M20 is the EVAP Fuel tank breather valve. If the valve is stuck open or if the hose has a tear, it will cause a significant vacuum leak. The green hose connects to a brass barb on the underside of the throttle body. It...
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So you’ve heard that you should change the timing belt on an M20 every 50k miles or 4 years (whichever comes first), because in case of failure the valves will hit the pistons, rocker arms will break, and you’ll be looking at a top end rebuild or a new engine. But what many people,...
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If you’ve purchased an aftermarket underpanel for your E30, you’ve probably realized it doesnt not come with sound insulation. This sound insulation is called Jute. OEM PN 51488229734 provides for just enough insulation to do one under panel.   The insulation has one sticky side and one cloth side; doubling the layers will make...
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In the vast majority of cases, vacuum leaks are to blame for poor or inconsistent idle issues on M20 engines found in E30’s. Vacuum leaks basically mean air that is entering the engine where the air flow meter has not had a chance to meter it. Unmetered air, is unexpected air, and as such...
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This is an excerpt from the factory E30 repair manual instructing how to mechanically and electrically test the ICV (idle control valve) for an M20 engine.
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In the world of alternators the one used on most all E30’s is quite simple and straight forward. The Bosch alternators are a a two post design, with D+ and B+ terminals. B+ (also called 30) is the larger of the two and routes through the starter, then the battery junction box and finally...
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Near most idle issues are derived from unmetered air entering the intake past the AFM (Airflow Meter). Simplified, it means you have a hole in one of your connections, gasket matting surfaces or intake related hoses. Un-metered air is a fancy way of saying that you have additional air entering your system that the...
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