i have one of the older mrev's with the valve that you have to turn when the temperature drop's below 55 degrees. the way understand it, in hot temperature, the valve prevents hot fluid (anti-freeze?) from heating up the plenum/throttle body.

But what will happen in cold temperature if I don't open up the valve?

i'm not talking about real cold, i live in sunny southern California and last winter, for example, the temps never even dipped below 55. But now all of a sudden i am seeing colder temperatures at night (low 40's). So i wanna know what will happen if I don't open up the valve? Is it something that only affects the car at startup? (i.e. if i start up when the whether is 55, but then i drive into the night when the whether hits 40's but by this point the car is warm, is that gonna affect anything).

its a bit of a pain in the *** to access (on the older model i'd have to take off the engine cover and use some sort of tool to turn it. since i don't own any tools or really want to start unscrewing things in my engine, i'm probably just gonna wait and see what happens.)

 

As I understand it, you open the valve when the temps drop near or below freezing. I have had mine closed here in Texas for most all year. I even had it closed when we dropped to freezing, but no problems. If you lived in Canada, you should be worried about opening it. For sunny California, forget it and enjoy the cold air!

 

Most parts of Southern California won't get cold enough for you to start seeing any issues, especially if you park in a garage overnight. If you park outside overnight, then you'll be more affected by the colder temps and will have to open it up at slightly warmer temps. If you live inland or a remote area that sees consistant cold temps, say like teens, 20's, etc... you may want to open it up for the month or two when it's real bad, but that's not common for most of So Cal. Same goes for most of AZ too because our winters are very mild as well.

The first issues you'll probably notice are sluggish performance and decreased throttle response, however, they'll go away once everything's warmed up. You may have issues with the idle too, but again, that's just until the car warms up.

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Justin

 

thanks for the responses. this makes me feel assured b/c i never push my car b4 its properly warmed up. i even wait 30secs or so before even backing out of my parking spot for the oil to circulate a bit. i was concerned that the throttle would get jammed shut or something along those lines. but this doesn't seem to be the case. thanks again