If the viscous coupling on the fan is shot you will hear the vroom when you hit the throttle in neutral when the engine is hot. You know the noise you get when starting cold that disappears after a minute. One of my 740's does this and I'm reluctant to change the viscous coupler cos it sounds cool, but it does run a bit cold. Sad, I know, but I keep getting comments about how good my V8 sounds LOL (it's a 4 cylinder 2.0 litre) :) Plus it warns pedestrians not to run the crossing lights LOL.
Mebbe thats the problem, or part of it. I don't think the splash guard will make much difference, my theory is that it's there to catch forgotten tools and stop oil drips.
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'86 740 GLT 2.3 injection 7 seater estate, '89 740 SE 2.0 injection saloon, '87 BMW 316 carb Coupe