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Purpose of Motor Covers?

Posted By: tc1446

Purpose of Motor Covers? - 09/10/19 10:32 PM

Almost all cars come with covers that hid most of the actual motor so that is about all you see when you raise the hood. I recently pulled the cover off of my Kia Soul and it had a thick layer of foam insulation underneath. I can't hear any difference in the sound of the motor without it. Other than "looks", is there any real purpose for these covers?
Posted By: ad244

Re: Purpose of Motor Covers? - 09/10/19 10:37 PM

So you cant hear the rod knock as bad when it's in warranty
Posted By: Kira

Re: Purpose of Motor Covers? - 09/10/19 10:41 PM

Other covers have no foam etc.

I think "looks" is it. Covering the organized rats' nest of scraggly wires and plugs.
Posted By: atikovi

Re: Purpose of Motor Covers? - 09/10/19 10:52 PM

Helps keep engine heat from damaging paint on the hood.
Posted By: ctechbob

Re: Purpose of Motor Covers? - 09/10/19 11:00 PM

Lets people that care about cars know that you gave a flip during your ownership to keep up with them when they're looking at buying your used car?

I actually used that as a measure when I bought my TL. 8 times out of 10 the battery cover is missing and that was actually a turn off when I was looking.
Posted By: skyactiv

Re: Purpose of Motor Covers? - 09/10/19 11:07 PM

It made a sound difference on a 2012 Mazda3 my wife had. The Mazda had a DI engine and the injectors were louder with the cover off.
Posted By: slacktide_bitog

Re: Purpose of Motor Covers? - 09/11/19 12:06 AM

I like the one from the first-gen Kia Sedona:

[Linked Image from images.hgmsites.net]

Originally Posted by ad244


So you cant hear the rod knock as bad when it's in warranty


LOL
Posted By: Mad_Hatter

Re: Purpose of Motor Covers? - 09/11/19 12:13 AM

I take it off in summer to improve airflow and put it back on in the cooler fall/winter months. Have I noticed an actual difference in coolant temps, no. Have I noticed a discernable difference in engine noise off or on in the cabin, no.

But I do it none the less..😂
Posted By: Reddy45

Re: Purpose of Motor Covers? - 09/11/19 12:14 AM

It's 1 additional thing for the mechanic or body shop to forget to install.
Posted By: 92saturnsl2

Re: Purpose of Motor Covers? - 09/11/19 12:20 AM

It's there for aesthetics, sure, but mostly it's there for sound deadening. The foam lining under the hood is what insulates the paint from the engine heat, the engine cover has little or nothing to do with the paint.
Posted By: 02SE

Re: Purpose of Motor Covers? - 09/11/19 12:24 AM

As mentioned sound suppression and aesthetics for the majority of the general public that don't know anything about engines, and just like the 'finished look' a cover provides.
Posted By: pitzel

Re: Purpose of Motor Covers? - 09/11/19 12:56 AM

I always thought those covers were 'maintenance deterrents'. As in, they want customers to think that engines are just black boxes that cannot possibly be at all fixed without fancy-dancy factory tools and training.

In the sales process, they may also reduce the perception of complexity, and thus, things that can break.
Posted By: Eddie

Re: Purpose of Motor Covers? - 09/11/19 12:56 AM

Helps keep the engine clean, helps with noise and in some cases it directs air over the cylinder head. I always keep them on for these reasons. Ed
Posted By: Kestas

Re: Purpose of Motor Covers? - 09/11/19 01:20 AM

When I worked for one of the auto manufacturers in the 80s, they had a task force called the Underhood Appearance Group, making sure the parts manufactured didn't look too odd when the hood is lifted. They didn't like the Prussian blue used on the cast aluminum master cylinders being built. It was there for crack detection during manufacture.

I guess they gave up and just went with an engine cover.

For two cars in my stable I took the engine covers off and put them on the shelf. They'll go back on when I sell the car.

Considering the troubling trend of tight underhood space and designers having more trouble trying to shed heat from the engine, and specifying more heat resistant materials, cars would be better off without these covers.
Posted By: rubberchicken

Re: Purpose of Motor Covers? - 09/11/19 03:08 AM

About 15 years ago, I read an article in either Motor Trend or Car and Driver that was talking about the trend towards aesthetic covers vs. cast and machined engine parts that were "beautified ". The article said that it was cheaper to design in a plastic cover to cover up an ugly engine, than compared to a pretty engine with nice intake, valve covers, hoses etc. About the same time, a similar trend was noted in the motorcycle industry. I am not sure if one trend predated the other, but it seems to be a reasonable explanation.
Posted By: Mad_Hatter

Re: Purpose of Motor Covers? - 09/11/19 03:13 AM

Originally Posted by Kestas
Considering the troubling trend of tight underhood space and designers having more trouble trying to shed heat from the engine, and specifying more heat resistant materials, cars would be better off without these covers.

My sentiments exactly 👍
Posted By: CR94

Re: Purpose of Motor Covers? - 09/11/19 03:58 AM

Originally Posted by 02SE
As mentioned sound suppression and aesthetics for the majority of the general public that don't know anything about engines, and just like the 'finished look' a cover provides.
They're also less expensive than giving the actual valve cover a "finished look," as some manufacturers used to do.
Posted By: sloinker

Re: Purpose of Motor Covers? - 09/11/19 04:57 AM

I've seen a few new cars recently that have foregone the covers. May be a new trend.
Posted By: wemay

Re: Purpose of Motor Covers? - 09/11/19 07:16 AM

I was in the "it's only for aesthetics camp too..."

"In cooler climates it helps warm up the engine faster. In hotter climates it helps dissipate heat from the hood to protect the paint, even if spec'd with an under hood lining."

This is what I was told by a KIA service tech when he noticed I had removed mine. Not sure I totally buy it but if I get hood paint issues while under warranty, I don't want to give anyone an easy "out". So for now it's back on.
Posted By: mehullica

Re: Purpose of Motor Covers? - 09/11/19 07:30 AM

Aerodynamics. Help lower the coefficient of drag. Less turbulent air under the hood coming in from the grill at high speeds. No manufacturer will waste money on anything underneath the hood unless it increases MPG
Posted By: Virtus_Probi

Re: Purpose of Motor Covers? - 09/11/19 11:28 AM

Originally Posted by Kestas
When I worked for one of the auto manufacturers in the 80s, they had a task force called the Underhood Appearance Group, making sure the parts manufactured didn't look too odd when the hood is lifted. They didn't like the Prussian blue used on the cast aluminum master cylinders being built. It was there for crack detection during manufacture.
I guess they gave up and just went with an engine cover.
For two cars in my stable I took the engine covers off and put them on the shelf. They'll go back on when I sell the car.
Considering the troubling trend of tight underhood space and designers having more trouble trying to shed heat from the engine, and specifying more heat resistant materials, cars would be better off without these covers.

Didn't Bill Alexander recommend using Alizarin Crimson instead?
;^)
He was the guy who taught Bob Ross how to paint, went from being a German POW in WWII to having a PBS painting show.
I remember him hollering exuberantly about spreading his magic vhite on the canvas with ein grossus brush!
I always wondered if he favored Prussian Blue because of his ancestry...
Posted By: hallstevenson

Re: Purpose of Motor Covers? - 09/11/19 01:43 PM

On our Fusion, the noise difference with it on vs off is substantial.

I think it looks 100% better with it on too.
Posted By: PimTac

Re: Purpose of Motor Covers? - 09/11/19 01:50 PM

They reduce noise, keep the top of the engine cleaner, protect any wires and lines, and clean up the looks. It will depend on the manufacturer as well.
Posted By: bdcardinal

Re: Purpose of Motor Covers? - 09/11/19 03:19 PM

Originally Posted by sloinker
I've seen a few new cars recently that have foregone the covers. May be a new trend.


The new Ford Rangers only have them on the Lariat. Ford even issued a SSM stating that ordering one for a non Lariat was unwarrantable and claims would be denied. Guess what sales came in demanding had to be covered under warranty...
Posted By: Gimpy1

Re: Purpose of Motor Covers? - 09/11/19 03:26 PM

The engine covers on the GTO where know to cut the fuel line on the driver's side, so most folks took them off. IMHO most covers are for aesthetic reasons, except for VW they mount the fuse box on top of the plastic battery cover.
Posted By: Linctex

Re: Purpose of Motor Covers? - 09/11/19 04:30 PM

Originally Posted by ctechbob
Lets people that care about cars know that you gave a flip during your ownership to keep up with them when they're looking at buying your used car?

I actually used that as a measure when I bought my TL. 8 times out of 10 the battery cover is missing and that was actually a turn off when I was looking.


PFFFTTtttt ........ Most Acura TL owners are 100% unaware their car ever had a battery cover.


Originally Posted by Reddy45
It's 1 additional thing for the mechanic or body shop to forget to install.


+ 1,000% !!!!!!!!
Posted By: DGXR

Re: Purpose of Motor Covers? - 09/11/19 05:20 PM

I'd say the engine covers are for cosmetics and the foam is for sound deadening. Some of the late model Mustang V8s don't have an engine cover, which surprises me not only because it is Ford's flagship sports model, but also because they look terrible underhood with various hard lines and hoses and wires running all over the place. But whatever, they still sell like hotcakes.
Posted By: Railrust

Re: Purpose of Motor Covers? - 09/11/19 08:20 PM

I think depending on the manufacturer and engine design it can be used for sound deadening, especially in direct injection motors. Ford has done this, Lexus, several others. Other times I think it's just for looks, and like someone else said...to deter someone from works on the car. Honestly I've worked on some cars where removing the covers were worse than working on the engine itself.
Posted By: Yah-Tah-Hey

Re: Purpose of Motor Covers? - 09/11/19 08:23 PM

Cosmetic
Posted By: BMWTurboDzl

Re: Purpose of Motor Covers? - 09/12/19 11:27 AM

Hide the mess of wires, fuel lines, etc. etc. It also minimizes dust accumulation, provides some sound deadening (sound deadening material can be held in place between the cover and the engine).
Posted By: SeaJay

Re: Purpose of Motor Covers? - 09/12/19 01:42 PM

Yes, there are some (minor) advantages to the engine performance, cooling, noise, etc.

But lots of folks desire that the engine compartment looks clean and neat, this hides some of the dirt.
Posted By: 1978elcamino

Re: Purpose of Motor Covers? - 09/12/19 05:42 PM

They are called appearance covers
Posted By: buster

Re: Purpose of Motor Covers? - 09/12/19 10:48 PM

The foam on my 2015 started to come off so I removed the engine cover and never put it back on. I liked it better without it.
Posted By: OTCW

Re: Purpose of Motor Covers? - 09/12/19 11:45 PM

Some foams are fire suppresants as they melt if the engine catches fire.
Posted By: I_4

Re: Purpose of Motor Covers? - 09/13/19 12:06 PM

They make a nice "mouse house" where the little rodents can stay warm while feasting on nuts and wire insulation. Seen that more than once.
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