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RX-8 and heat wave

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Old Jul 18, 2006 | 07:21 PM
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Thumbs down RX-8 and heat wave

I had a scary experience today:
I was driving home from work this afternoon, and got stuck in traffic on I-95 in Philadelphia. After something like 15 minutes of stop and go, I noticed that needle of water temperature gauge started to move right from its usual position - 2 points left from the middle. It moved up to about 2 points RIGHT from the middle. At that point I also noticed that idle changed to 1500 rpm from usual under 1000. Probably computer tried to increase water circulation that way. Outside temperature was 105 at that point. I already started to seach a place to pull over. But luckily traffic started to move, and when I was able to get to regular highway speed, temperature gauge returned to its usual reading. When I got home I looked at the engine and didn't find any coolant spots, oil level also was at top mark.
So it seems that this car can't tolerate heat over 100F, and it's not surprise that there are so many engines failed in places like NV, AZ or TX.

Last edited by rx8-rus; Jul 18, 2006 at 08:41 PM.
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Old Jul 18, 2006 | 07:23 PM
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Is yours an automatic?
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Old Jul 18, 2006 | 07:30 PM
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thats hardly anything- you should be on adyno whentit spikes and steam starts rolling out from under the hood. that's scary
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Old Jul 18, 2006 | 07:30 PM
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Originally Posted by otherside
Is yours an automatic?
No, manual. I was in similar conditions last year, but never saw needle moving. Could it be a result from latest flash update update month ago?
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Old Jul 18, 2006 | 07:32 PM
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IP check.
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Old Jul 18, 2006 | 07:51 PM
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When you say no "coolant spots" does that mean you checked the radiator and overflow tank for coolant levels?
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Old Jul 18, 2006 | 07:51 PM
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I would check your coolant. I have been in 100+ stop-n-go for hours (live in So. Cal.) and other extreme to the edge driving at 100+ and my thermo never goes past half. Maybe you have a "winter" mix of antifreeze and water. But I don't think you have anything to worry about only being 2 notches above half.
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Old Jul 18, 2006 | 07:53 PM
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Originally Posted by saturn
When you say no "coolant spots" does that mean you checked the radiator and overflow tank for coolant levels?
Yes I did. Level seems to be normal and no signs of leak. I'll check level again tomorrow, when it cools down.
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Old Jul 18, 2006 | 08:00 PM
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Those of us in Texas see 105° pretty often. I haven't seen mine get hot yet although most of my driving is highway. Even in the city it hasn't gotten hot yet.

A side note the AC works great as long as the engine is about 1500 RPM. at an idle the AC compressor just doesn't turn fast enough probably since the motor is a twister.
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Old Jul 18, 2006 | 08:23 PM
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It always kills me when I see heat issues from people in the North East. I live in the freaking desert! For some reason the 8 I have owned for 3 years now has made it through 3 summers of constant 100+ temps with no heat problems.
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Old Jul 18, 2006 | 08:29 PM
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I also never had heat related problems before. This is my third summer with RX-8. Thast's why I said it was scary.
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Old Jul 18, 2006 | 08:42 PM
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Originally Posted by NoTears316
It always kills me when I see heat issues from people in the North East. I live in the freaking desert! For some reason the 8 I have owned for 3 years now has made it through 3 summers of constant 100+ temps with no heat problems.
AC's have to work a lot harder when they have to dehumidify humid air so you're going to have less problems than someone from the NE during a very hot and humid day.
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Old Jul 18, 2006 | 08:46 PM
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Just a reminder: Keeping your recirculate button on will improve your AC efficiency by at least 35%.
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Old Jul 18, 2006 | 08:56 PM
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From: Bellevue WA
You all live in the Artic.
I was driving home the other day and on the freeway the
outside temp was 127 degrees.
Ya bunch of pansies.
Temps here in the 110's to 120's are quite common in the summer.
Wheres my Slurpee, and my sunscreen?
Oh and the 2 Rx-8's I have had in the past 2 years have done just fine!
Attached Thumbnails RX-8 and heat wave-mini-temp05152006-002.jpg  

Last edited by Easy_E1; Jul 18, 2006 at 08:59 PM.
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Old Jul 18, 2006 | 09:07 PM
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Originally Posted by Easy_E1
You all live in the Artic.
I was driving home the other day and on the freeway the
outside temp was 127 degrees.
Ya bunch of pansies.
Temps here in the 110's to 120's are quite common in the summer.
Wheres my Slurpee, and my sunscreen?
Oh and the 2 Rx-8's I have had in the past 2 years have done just fine!
I am looking for land (developable) in Queens Creek, Marana and netherparts.
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Old Jul 18, 2006 | 09:21 PM
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From: Bellevue WA
Originally Posted by RotoRocket
I am looking for land (developable) in Queens Creek, Marana and netherparts.
Hurry up before the place melts.
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Old Jul 18, 2006 | 10:31 PM
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Originally Posted by Easy_E1
You all live in the Artic.
I was driving home the other day and on the freeway the
outside temp was 127 degrees.
Ya bunch of pansies.
Temps here in the 110's to 120's are quite common in the summer.
Wheres my Slurpee, and my sunscreen?
Oh and the 2 Rx-8's I have had in the past 2 years have done just fine!
You live in the desert. You don't know what humidity is.
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Old Jul 18, 2006 | 10:40 PM
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I heard that when it's 120 degrees in Arizona it really feels like 65 degrees in Michigan, because it's a dry heat.
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Old Jul 19, 2006 | 07:51 AM
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From: Milan, Michigan
Michigan feels like a sauna.

The desert feels more like when you open the oven to check your food...!!!!'
I remember when I went to Vegas, wow....... it was 115+ and I've never experienced hot air like that day.....
But I rather have desert like weather and not Michigan weather..... the humidity just kills....
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Old Jul 19, 2006 | 08:18 AM
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Thumbs up

Originally Posted by rx8-rus
I had a scary experience today:
I was driving home from work this afternoon, and got stuck in traffic on I-95 in Philadelphia. After something like 15 minutes of stop and go, I noticed that needle of water temperature gauge started to move right from its usual position - 2 points left from the middle. It moved up to about 2 points RIGHT from the middle. At that point I also noticed that idle changed to 1500 rpm from usual under 1000. Probably computer tried to increase water circulation that way. Outside temperature was 105 at that point. I already started to seach a place to pull over. But luckily traffic started to move, and when I was able to get to regular highway speed, temperature gauge returned to its usual reading. When I got home I looked at the engine and didn't find any coolant spots, oil level also was at top mark.
So it seems that this car can't tolerate heat over 100F, and it's not surprise that there are so many engines failed in places like NV, AZ or TX.
It hit 103 here yesterday afternoon, no problems. The A/C did just fine, partly because I did the simple A/C insulation DIY a couple days ago (cools noticeably better). This is my 2nd hot, humid summer with the 8, and it "tolerates" 100+ temps just fine.
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Old Jul 19, 2006 | 08:36 AM
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Originally Posted by zoom44
thats hardly anything- you should be on adyno whentit spikes and steam starts rolling out from under the hood. that's scary
Yup I hate the heat. I was at the track last Fri & Sat. Only one car on the Dyno lol it was just way too hot at 119!!!. Then a lot of the D1 cars where geting way to hot.

Remind me never to buy a 350Z and try to drift it. Every run something went wrong on that car
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Old Jul 19, 2006 | 08:36 AM
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Originally Posted by saturn
You live in the desert. You don't know what humidity is.
Okay, right about now we need some physicist who passed thermodynamics to chime in.

Higher humidity "feels" hotter to us since it interferes with the way our body cools itself. We cool down when we perspire and it evaporates. But when it's very humid, our perspiration doesn't evaporate as readily, so we don't cool as readily as we do when in a dry environment.

Now, as to our cars... they don't cool by perspiration/evaporation, but by transferring heat to the air passing through the radiators. So my big question is: What is the difference in heat transfer between dry air and humid air at the same temperature?

Ever notice than a "wet" cold feels much colder than a "dry" cold? Years ago I lived at the beach during the winter and drove my motorcycle to work. Regardless of temperature, I could always tell the difference between an onshore breeze and an offshore breeze, because the humid air felt MUCH colder. My warm body transferred heat to the cooler air much faster if it was humid.

I suspect our autos transfer heat more efficiently in humid conditions than in dry conditions, even though it feels much hotter to us.
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Old Jul 19, 2006 | 08:51 AM
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Originally Posted by Paul_in_DC
Okay, right about now we need some physicist who passed thermodynamics to chime in.

Higher humidity "feels" hotter to us since it interferes with the way our body cools itself. We cool down when we perspire and it evaporates. But when it's very humid, our perspiration doesn't evaporate as readily, so we don't cool as readily as we do when in a dry environment.

Now, as to our cars... they don't cool by perspiration/evaporation, but by transferring heat to the air passing through the radiators. So my big question is: What is the difference in heat transfer between dry air and humid air at the same temperature?

Ever notice than a "wet" cold feels much colder than a "dry" cold? Years ago I lived at the beach during the winter and drove my motorcycle to work. Regardless of temperature, I could always tell the difference between an onshore breeze and an offshore breeze, because the humid air felt MUCH colder. My warm body transferred heat to the cooler air much faster if it was humid.

I suspect our autos transfer heat more efficiently in humid conditions than in dry conditions, even though it feels much hotter to us.
Ugh, this is going to turn into one of those "I took physics -- I'm an expert" threads.
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Old Jul 19, 2006 | 08:56 AM
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Yesterday was our hottest/most humid day of the year, but my '8 did fine. The fan stayed on for quite some time after I pulled into the garage tho', as expected.

Humid air is less dense than dry air and therefore more heat transfer capability (non-evaporative discussion). Humid air also has a latent heat component. I'm not a physicist, but I am a pilot, so relative air density is very important to me. Oh, and I stayed at a Holiday Inn Express last night.

btw: keep in mind that there is no such thing as cold. It is just a matter of heat transfer.

Last edited by Huey52; Jul 19, 2006 at 01:09 PM.
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Old Jul 19, 2006 | 09:43 AM
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Does anyone have an 8 in Miami? Its got both high humidity and 100+ temps. That must be the true test.
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