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Old 12-09-2010, 02:38 AM   #7 (permalink)
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Svietlana II - '13 Peugeot 308SW e-HDI 6sp
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Originally Posted by puddleglum View Post
I know that a friend of mine from years past found a heat lamp mounted under his VW Beetle helped quite a bit with cold starting. I thought the heater might do the same thing, if it could raise the under hood temp. enough.
A heat lamp directed at the oil pan or engine block would be better than a heater since its radiation would go straight to where it's needed, while the heater first heats air, which later gives only some of its heat to the engine. The heat lamp is immune to drafts, and warms only what it's directed at. The heater, on the other hand, will waste energy warming everything in the engine bay: not only engine, but also radiator, wires, fluid reservoirs, ducts, hood and side walls, etc. Sure, the engine bay will be warm, but you'd have to keep that heater on all night for the engine block to soak up some heat.

Originally Posted by puddleglum View Post
Oil pan heaters do help, but they have to be on a smooth surface below the oil level. I could put one on the engine pan, but there is no flat spot on the transmission. Also, I think the ECU looks at coolant temp., not oil temp. when determining fuel mixture.
Flat or curved, but no compound curves. A coolant/block heater won't heat your oil, so even if the coolant is warm, your oil has the density of thick molasses. With an oil pan heater, once the oil warms up it transfers some heat upwards to the rest of the engine. It may not have a noticeable effect on coolant temperature at start up, but the coolant will warm up faster once it starts circulating. Thinner, warmer oil is what you want most if your trips are short.
e·co·mod·ding: the art of turning vehicles into what they should be

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Piwoslaw's Peugeot 307sw modding thread

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