Car's engine bays

I haven’t looked at any new cars lately. I haven’t even looked closely at my '99 Cherokee. But I’ve noticed, when looking at some cars, that the engine bays in American cars tend to be painted black, while the ones in foreign cars are body colour. Why? Wouldn’t it be easier to paint the whole body – inculding the engine bay – at the same time, instead of painting the engine bays black?

I don’t know the answer to your question, but I have an interesting observation.

I bought a new car last year, and when I checked the oil for the first time a few months later (before a trip), I realized I had never opened the hood . :eek: This from someone who normally does his own oil changes, brakes, bearings, and minor repairs like air conditioning, starter motors, etc.

My car has no dipstick. For real. The only reason to open the hood is replace the washer fluid.

As to the OP’s question, I have a American SUV and the engine bay is the same color as the body. So was the previous one.

I don’t recall seeing any non-car-color engine bays, except where the engine has been removed, or the car has been very seriously detailed.

My American car and my imported car both have the body color on the wheel skirts and a black firewall.

I doubt they care what color it comes out as long as it’s either the car color or a neutral color like black, white or primer grey.

I suppose it just depends on what stage the parts are attached to a car vis-à-vis when the painting is done. For uni-body construction, painting the whole thing at once is the obvious choice. For cars with bolted instead of welded skirts, neutral would be best.

My current car, a Lexus ES 300, has an engine bay the same as the body…green.

The same for my first car, a '77 pontiac sunbird hatchback, made in Canada.

Well I know a reason why some people do it. Some people are of the belief that by painting the engine bay black, it will absorb radiant heat from the engine better, and thus help to cool the engine.

At least, that’s their belief, and I’ve heard it repeated many times by many pseudo-scientific car folks. Whether or not it works to any measurable extent…I have a headache.

Uh, in the factory the entire car body is painted the same color. Maybe… just maybe sometimes the chassis components may have type of shielding that’s not strictly-speaking the firewall but some other protective shield. In the case of 100% of the cars that I deal with, this isn’t the case and the entire engine compartment is body color.

That would only work if the body could conduct that heat and then radiate it effectively to the outside.

It seems I’ve been looking at the engine bays of '60s cars. There’s a '68 Cougar in the shop with my MGB. Its engine bay is black. The exterior of the car was resprayed a very long time ago, but I’m pretty sure the resto guy said the black engine bay was original. I did see some original stickers in it.

I was looking at an MGB on eBay. (No, I’m not getting another.) It was also a respray, and it was black under the bonnet. The engine had been rebuilt and repainted, so the hole must have been painted black at that time. And the engine compartment of my '63 Herald was painted black at some point.

So perhaps it is that I’ve been seeing cars that were painted at some point. But I’m pretty sure the '68 Cougar was like that ‘back in the day’.

I can think of two possibilities as to why the engine bays would be black. One is that during the 60s, the cars had fairly open grills, so painting the bay black would help hide the ugliness that’s things like braces, struts, etc. The other reason is so that if the engine dripped oil or other fluids routinely, they wouldn’t be so noticable. (Some engines were pretty notorious for flinging grease and the like while they were running.) Also, now that I think about it, back before things like PCV valves and the like, you had a bunch of nasty fumes under the hood, those might discolor the paint of that era, so black would conceal it.

When I first started to drive, I had several ‘60s and ‘70s american cars.

My first car was a 1963 Chevy Impala. It was a medium dark blue. I recall the engine compartment was dark, but don’t remember if it was the same blue or just black.

Next came a ’65 Pontiac 2+2 (basically the same car as the Catalina or Bonneville, but with performance and other options). The engine compartment was definitely the same color as the body: white.

At other times I had a ’71 mustang, and an early ‘60s Ford Falcon station wagon. In both of these I remember the engine compartment (or at least the inner fenders and firewall) were the body color.

Not a huge sample, but at least some American cars of that vintage had the body color under the hood.

I think some of you are over thinking this.
Back in the days of old, the entire body would be primered in black. then the hood and trunk would be shut, and the outside of the body would be sprayed whatever color. The engine bay and trunk would remain black, as they had never been painted.

Some cars, at any rate. I know that some makes have a “splatter” color only in the trunk (IIRC, Chrysler was one of the makes that had that). You can buy specialty paint to replicate it.