From 1989 forward; M20 engines (325i, 325is, 325ix, 325, 325e, 325es) used what were called injector harnesses for the fuel injector connectors. Prior to 1989 M20 engines used individual two prong connectors for each individual injector. There are three main benefits to the later harness, the first benefit is that the later harness has...
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After blowing a coolant hose I had accidentally pulled off the ‘fuel tank breather valve’ off of its nipple on the throttle body plate. The symptoms where: -Check engine code 1222 but only at idle after 10 seconds and would disappear when throttle was given -Uneven idle This is what the breather valve looks...
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It may seem like a battery is a battery is a battery but  there are some critical differences between batteries. There are essentially two types of batteries you can choose from; AGM and Lead batteries. Many new BMW’s like E90 come with AGM batteries, these batteries use a technology called Absorbed glass mat. Without...
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Many people are not aware that there are different types of brake lines, different types of flares (with different unions), different materials that they can be made of, or how to cut, and flare them properly. The most common brake line size for most BMW’s and particularly true for E30’s is 4.75mm with a...
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Supplementary guide for trailing arm bushings: https://www.rtsauto.com/the-easy-way-to-remove-and-install-e30-trailing-arm-bushings/   This is a step by step DIY on how to remove the whole E30 rear subframe assembly, and how to remove and install stock and aftermarket subframe bushings:   1. Put car on 4 jack stands, in the back since you will be removing the subframe,...
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My way is not only faster then most traditional ways, but its also makes the trailing arm bushing come out without much resistance. Things you will need: 30mm socket Bigger C-clamp or PREFERABLY a vise Box cutter KY lube (not required, but if you have it I recommend using it)   First Cut off...
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There are two basic challenges to changing the transmission fluid on the E30 for the DIY’er. The first is to find a 17mm hex (a shallow 17mm at that) to undo the transmission fill and drain plugs. The second challenge is how to actually get new fluid back in because the drain plug is...
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By design E30 shifters are doomed to go sloppy over time because the materials that keep it tight are made out of things like rubber and hard plastic. Here is the no-bullshit way of getting that shifter tight again.   You will need parts 6 and 13 from the dealer. Part 2 from a...
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There is a very high probability that through the life of an E30 the odometer gears will go out. If your odometer gears are original and are still functioning as they should then consider yourself lucky. If you plan to own your E30 for the distant future then it will be worth bookmarking this page!...
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Most every maker of m60/m62 engine mounts currently is basing off the idea of using subframe spacers. I  have covered where this idea of using subframe spacers came from here: https://www.rtsauto.com/mounting-an-m60-m62-without-subframe-spacers-and-without-drivetrain-angle/   Essentially the person who wrote one of the first DIY for the swap used subframe spacers, and because others were religiously following...
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