You know, that plastic shield on top of the engine compartment, the one that blocks view and access to almost everything. I removed mine thousands of miles ago and have seen no effects, bad or good. Why is it there, and why not remove it and leave it off?
Its pretty obvious. Its there to force cool air coming in through the grill into the radiator and keeps warm engine air from reaching the front of the radiator. All cars use some sort of seal there. You haven't noticed cause its winter. In the dead of summer you might. It needs to be there.
It also reduces dust and sand that comes over the rad. onto the engine components. It's not absolutely necessary though, as you have found. Things just work a little better with it in than out.
Toyota surely wouldn't have spent a a few bucks and engineer hours for the cover if it wasn't needed.
Cooling drag is a big deal in aircraft. Any air that comes in through the grill that doesn't go though the radiator introduces drag that has no positive effect. I'm willing to bet that at highway speeds you can see a difference in MPG with and without the baffle in place. Drag goes up with the square of your speed. Do this experiment in the morning when the temperature is cool - cool air is denser and causes more drag.
Removal of the shield may somewhat impact A/C performance at a stop, or very low speeds. The cooling fans may not be able to pull as much air through the condenser On FJ Cruisers, one *must* remove the cover to properly clean the radiator. Any sort of driving in sand and especially mud will result in troublesome overheating. A surprising amount of trash can collect between the condenser and radiator Not sure if any trash will accumulate between the condenser and radiator of a Prius. I checked last summer and it was just dusty
If I could get the doctor's numbers I'd pull mine in a minute. "Toyota surely wouldn't have spent a a few bucks and engineer hours for the cover if it wasn't needed." Toyota didn't design or build the most fuel efficient car possible. There are any number of things in the car that aren't needed and a bunch of "needed stuff" was left off. "Need" is in the mind of the owner.
I believe that I can answer my own question. The "radiator cover" is designed to discourage owners from spray-washing the engine compartment. Since the Prius is so dependent on its electrical electronic subsystems, water is quite hazardous, much more so than on a car with a conventional ICE. The majority of Prius owners, like the owners of any conventional passenger car, never look under the hood, much less are willing to take a screwdriver to a component. The cover can be safely removed and stored until the day one wants to sell the car. The sad truth is that all of the effort spent on maintaining your Prius, if you are a techie, is completely wasted when you go to sell the car. Joe (Jill) average and his (her) spouse will look at the condition of the body and interior, and make their offer accordingly.
+1 Mention how often you changed the cvt fluid, or had the dealership flush the brake fluid, they'll look at you as if you stepped out of a flying saucer "Nanoo nanoo take me to your leader!" For example, with my FJ Cruiser, not only have I already changed all the gear oil a couple of times, I've also flushed the brake fluid (A DIY job on the FJ), and even changed the power steering fluid. Gives me peace of mind Do you think if I ever sell the FJ, the average person looking at it will give a s*** I've done that work? Of course not! Like folks looking for a home. Say you have two homes in comparable neighborhoods, same size. One home was built by a real picky SOB, using ICF wall construction, tripane windows with dual low-e and dual argon fill, ductwork properly sealed and insulated, highest efficiency gas furnace and A/C, floorplan that is efficient and makes the most of natural winter sun for heat, Decra steel shingles on the roof, etc But, it's a plain looking house. No granite or slate, just regular formica countertops and nice, but plain, laminate flooring. No frills, though that house would probably hold up forever while costing 35-50% to heat cool as the neighbors The other house, looks ritzy with all sort of neat window treatments. Lots of granite and slate, fancy wood floors. A house that really wows you. Hidden behind the gyproc is sloppy insulation and wiring, very sloppy vapor barrier work. The cheapest furnace, A/C, shingles, and windows that money can barely buy Priced exactly the same, guess which house will be easier to sell? Especially if the wife refuses to even look at the gawdam furnace or A/C, and instead imagines all that impressive granite and slate Never underestimate how stupid humans really are
Worse: when you sell your house, the new owners will immediately rip out the improvements that you are especially proud of and replace them. This is an iron law.
This law is applicable with my recent home sale: we have tens of thousands of $s worth of granite desktops and builtins in three secondary bedrooms. The buyer is having this all taken out. This removal requires recarpeting the house BTW, no problem! To respond to the OP's original question, I'd say that the cover has a mostly cosmetic function.
Actually, after owning Pearl for just over two years, and detailing her frequently, I have come to the conclusion the cover does stop dust from entering the engine compartment. The cover has dust on the front up to where the hood rubber touches it, but very little after that. I'm leaving mine in. It's easy enough to remove if you want access to the front of the rad.
I've got a dumb question here. I just got my 2004 Prius serviced at the dealership about a month and a half ago (had an inverter coolant pump go bad). Anyway, I've been looking at my engine compartment off and on for the last few weeks, scratching my head, and it finally dawned on me that my radiator cover was missing. Then I started scratching my head some more wondering if I had a radiator cover in the first place. So, can someone confirm that the 2004 Prius has a radiator cover? If so, I need to give my dealer service department a call. -Nathan
[quote=morrisnk;951876]I've got a dumb question here. I just got my 2004 Prius serviced at the dealership about a month and a half ago (had an inverter coolant pump go bad). Anyway, I've been looking at my engine compartment off and on for the last few weeks, scratching my head, and it finally dawned on me that my radiator cover was missing. Then I started scratching my head some more wondering if I had a radiator cover in the first place. So, can someone confirm that the 2004 Prius has a radiator cover? If so, I need to give my dealer service department a call. -Nathan[/quote] Yes I believe in general they had a cover- at least mine did before I took it off and left it in the back of my garage. If you have to buy one make an offer.
Need is in the mind of the beholder. I have a smart key on my Prius, but I definitely don't need one.
I've been called grumpy and worse. I *wish* somebody would call me an Inglorious Basterd but it hasn't happened yet
Looks like the dealer's service department had it all along. They forgot to put it back on and decided to hold it for me until I came back in for my next oil change. That would have been a long time, considering I do my own oil changes. Well, it gave me an excuse to buy some ATF WS oil and replacement washers for my transaxle oil change. Anyway, thanks for the offer northwichita, those radiator covers are $95 new online. -Nathan
