It isn't the hot air in an engine bay that is going to set fire to oil, much rather the rather hot lump of metal called an exhaust just underneath, which is where any oil that happens to leak, is going to drip! Yes - it is unlikely (after all, it was oil leaks that stopped my heat exchangers from going rusty :wink: ) but don't just assume the air is the only hot thing. I spent a whole summer helping a friend build a very high-end kit car - a Ferrari P4, powered with a V8 engine from a 348. Passed its SVA, ready for road and track - we took it to a track day for initial testing and 2 hours later it was a smouldering wreck, never to be seen again - an oil line had come undone, and ignited on the exhaust. Just a cautionary tale - this is not to suggest that every oil can in an engine bay is going to spontaniously combust, but it ain't going to help....!
Having said all that, there is no account for muppertery of the highest order, so here is my tale...
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-I could say that this happened 'to a friend' - but that would be a lie. It was me....
Some years ago I was driving between Somerset and London, on the Glastonbury/Devizes/A4 route, with an american girlfriend I had at the time. You know how owning a Van you become very accustomed to the
smell of the engine, drifting up along the heater channels, and providing early warning of exhaust leaks, oil leaks, excessive heat even - well, for a while I had quite a strong smell of petrol.
I duely pulled into a layby near Frome, and walked around the back of the van (engine running) where I opened the engine hatch....
For quite a while my fuel tank sender had been broken (in fact, I only just fixed it after about 12 years) and to help reduce the inconveinience of running out of fuel, I took to carrying a plastic fuel can in the van 'just in case'. It was one of those red gallon ones. It was plastic. I kept it to the left of the engine bay. With fuel in. I know, I know....
....so as I opened the engine hatch, I saw that the plastic fuel can had managed to jump out of its 'secure' home in the left side of the engine bay, and was now resting on the (still running) fan belt. The fan belt had gradually worn through and melted the plastic, and a steady stream (think water pistol) of fuel was now jetting out of the can and soaking the dizzie/fuel pump/dynamo area of the engine. :shock: I batted the tank out of the van onto the road, and calmly (shaking) went to the front of the van and turned the engine off. "Nothing to worry about..." I told my passenger..."just a bot hot, we'll have a quick break here and let things cool off then set off...." I lied.
After enough time for all the spilt fuel to evaporate away, I closed the lid, thanking lucky stars, God or anyone else that would listen, for not letting my pride and joy burn to a cinder. A VERY lucky escape.
After a few more miles, as I gradually calmed down, I was aware that the petrol smell was still quite strong....my young american friend had seen the petrol can I had left behind in the layby and popped it back into the van (still pissing out petrol) - although to be fair, she had the presence of mind to put it in the back of the van (on the carpet, bedding etc) rather than in the engine bay itself. The strong smell of petrol remained for months....
All I have now is one of the automatic fire extinguisher systems that Aaron sorted out a few months ago. As someone else pointed out, there are plenty of other places to store things like spare oil - of full petrol cans....