mx5rx8

Hello, Newb 8 owner here. Search provided no threads discussing whether the plastic engine cover is functional in some way or if its just cosmetic? I'm sure it probably keeps the engine cleaner, but does it direct airflow for cooling or to the intake?

My initial thoughts were to yank it off and keep it off because it probably keeps the engine hotter and it makes adding oil and checking the dipstick alittle more difficult.

Your comments are appreciated.

HolyCross05

don't take it out

mx5rx8

Thanks for your response- would you care to share your experience as to why not? Anyone?

Glyphon

those on the forum that know what they are talking about in regards to the rx8, renesis, and rotary engines say that the plastic cover helps directs airflow under the hood, and acts as a sort of heat shield between the engine and the hood.

that said, in my experience with the car, i only use the cover in the winter, as it helps the engine get up to operating temperate quicker. in the summer, i take it off. last summer i noticed with the cover on, the cooling fans would run for a long time after shutting the car off.

in one instance, after driving for about 30 minutes, i pulled into a parking lot. turned the car off and got out. i noticed the fan was running. no big deal. just doing what it's supposed to be doing. 1.5 hour later, i came back to my car, and the fan was still running. it's still doing what its programmed to be doing, but i shouldn't have to run for 1.5 hours to accomplish it.

that day when i got home, i took the cover off, and the fan never ran for more than 5 minutes after shutting the car off for the rest of the summer, even on hotter days.

so, as soon as the temperature starts rising again, the cover is coming off again. YRMV, and i make no guarantees. that's just experiences that i've noticed with my car.

Nemesis8

iTrader: (3)

Another engine cover thread! I love it. Mine has been off for over two years now - no problems at 47 degrees North.

Raptor2k

There are quite a few threads that discuss the engine cover.

In summary, it's just cosmetic and the hood or anything else won't be affected if you take it off.

Glyphon - switching the ignition up one (without turning the engine on) and switching it back off will turn the fans off.

Glyphon

maybe so, but its easier to just take the cover off and not deal with it

mx5rx8

Right, coming from a geographic area where temps south of 40* are pretty rare, I was looking at it from the perspective of keeping the engine cooler by removing the cover. Those in colder climates would be concerned with keeping the engine warmer to avoid the cold start issues, I suppose.

Good point on the cover protecting against excessive heat on the hood and its pretty pearlescent white paint! Has anyone actually had paint damaged from the engine heat?

Raptor2k

^like I said, no

mx5rx8

Thanks for the summary guys. I swear, I did a search. Or my search kung fu is weak...

G8rboy

Mine has been off for 2 1/2 years with no problems... I've experienced 100+ degree days in the summer and -20 degree days in the winter. I'm convinced it's purely cosmetic. If Mazda was really concerned about it, they wouldn't be marketing their MazdaSpeed shock tower brace to RX8 owners, as the cover doesn't fit with that installed (or they would market an overpriced Mazdaspeed engine cover that was compatible with the MS STB ).

saturn

Necessary? Is it necessary for me to drink my own urine?

Of course not, but I do it anyway cause it's sterile and I like the taste.

Raptor2k

Was that necessary?

saturn

Guess you've never seen Dodgeball.

G8rboy

If you can dodge a wrench, you can dodge a ball

UFGator12

HAHHAHA, what a great quote. Props.

Raptor2k

Oh wowzorz, I can't believe I didn't remember that

Bah, I've only seen it once anyway, a rental is due

Hyperborea

If the engine was too hot and needed cooling then doing this does nothing to aid that. It only "fools" the engine computer and lets the heat stay where it is. The fans were on for a reason.

Raptor2k

Then you risk having the fans on forever (mine stay on forever in the summer, at least). It's a rotary, heat efficiency is bad to begin with. What's going to happen if the engine is hotter than normal? It's not going to melt or anything.

Hyperborea

If it actually would run "forever" and that's not just hyperbole then you have a temperature sensor problem. When the outside temperature is high it will take longer for the engine compartment temperature to come down (high school physics - Newton's law of cooling - the rate of cooling is proportional to the temperature difference).

What's going to happen if you don't let the fans run and cool the engine compartment down? How about premature aging of all of the rubber hosing, the battery, electrical wiring, alternator, and starter. When the car stops moving the fans keep the cooling air moving through the engine compartment.

KYLiquid

parts of the engine are aluminum, parts of the engine are iron, they absorb and release heat differently....if the engine is hot and the car feels the fans need to be on, then chances are that the car is too hot. If the engine runs to hot, or warms up/cools off to quickly it can cause parts to warp and that can lead to oil/coolant leaks. You would end up needing to rebuild the motor.

If you fan in running so long that you are getting a dead battery, go to a dealer and let them know that....thats a problem. The fan shouldnt run long enough to kill the battery in a stock car.

You should also check the coolant in the motor, the water pump, thermostat and the temp sensors the fans read to decided how long to run.

I live in orlando FL, and even in the summer where air temps are 98*F+ and the road temp is over 110*F, the car can run with the AC on and be driven hard and the fans dont run for more than 15-20 mins for me.

Glyphon

but if it was a temperature sensor problem, then it would behave the same with or without the engine cover.

Raptor2k

Newton's Law has nothing to do with my rx8's cooling fans.

A few degrees in temperature (or, er, the measurement of kinetic energy), which in turn activates whatever sensor for the fans to turn on, isn't going to significantly age components that are eventually replaceable.

Raptor2k

The dealership called it normal. Also, if the engine is getting hot as it always does in texan weather, and I decide to go on a long freeway trip, would this be called abusing my engine?

Hyperborea

If it was a temperature sensor problem then it probably doesn't make a difference about the engine cover. I suspect that it was more of a hyperbole problem.

Does the engine cover help direct the air flow from the fans to the engine? I don't know but it might. I suppose if somebody wants to "experiment" they could try it out after equally long drives on days with equal outdoor temperature and humidity and then time it from stopping the engine until the fans go off.