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First sub-zero cold start - HIGH revs?
For the first time since i've owned it, I went out from work today to start my car up in -2 degree temp.
I knew that they 8 would rev a little high, but after I started it, I watched the tach SOAR up to a hair past 4K and sit there for about 20 seconds or so. I was completely in shock...I wasn't touching the gas, or anything for that matter. I simply started it up and let the clutch out in neutral. I was tempted to shut it down but then feared the flooding issues. Now I was always told to keep it under 3K or so in cold weather...was this normal or should I be concerned? I know i was about to freak when i saw it was sitting up that high and there was nothing I could do. I'm aware that it revs a little higher in the winter, but this seemed excessive to me. Not to mention while it slowly dropped down, it was somewhat spuddering back down. I searched it out and didn't find any definites for sky-high cold start revs. Any thoughts or comments? |
That sounds a little high, mine sits around 2500-3000 for a 20-30 second run. But then at 2 degrees! Probably no worries, wait till next time. How did it run afterwards?
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as long as it comes down to around 1-1.5K after a minute or so. it's normal.
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Normal behavior. I see it every day lately.
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ran great afterwards, no problems once i got her warmed a lil.
on a minor note, i'm thinking I should have let it warm up a lil more tho. Pulled out after about a minute and made a right turn - BARELY tapped the gas to get out and my rear swung out a good 75 degrees like I was on ICE. I've never seen a tail kick out so quickly on a car...not even in the Cobra. Clearly, the throttle isn't all that user friendly on these subzero starts! Glad to hear it probably wasn't a damaging problem. I was kinda sweating bullets for a moment. |
+1 to Mazda-Rati's answer. And plus infinity to your own "minor" note - when it's single digits or less the 1-2 minute warmup is a sin.
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I have discovered that if you bleep the gas peddle it settles down to 3K for a few seconds then down to 2K for the next minute or so. That 4K run with a cold rotary really worries me.
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I started the car and it revved to about 4K before going down to 2K after about 30 seconds. But this only happened once and it was only after I hadn't taken her out for an entire 2 days. The temp read -5 and I've started her at much colder temps and only had that happen when she was sitting for 2 days. So maybe this car really is meant to be driven!
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Yea, I was actually somewhat afraid to even tap the gas when it's already sitting steady at 4K...
If it happens again, i know I'll be maybe contemplating that though. |
This is one of those issues that rotaries have always been set up to do. However it doesn't mean it's good for the engine. It isn't. When you first start a cold engine you don't really have an oil up in the engine. It's mostly in the pan. You start it and it takes a few seconds for the oil to reach every passage and bearing. It definitely isn't a good idea to spin the engine up faster right away during this period. It adds a small amount of wear to internal parts. The next thing is that you don't want the engine heating up too quickly as we have staggered cast iron and then aluminum housings which expand differently with temperature changes.
So why then does Mazda do this? Emissions! That's right, an environmentalist beaurocrat somewhere had enough of a say that it affects the longterm wear of your engine! Emissions standards say that your cat has to do it's job within so many seconds of starting. It can't do this when it's cold though so they need to heat it up as fast as possible but still slow enough not to kill the engine. A little wear is fine apparently. The engine revs up higher when it's colder because the cat has a greater temperature range to heat up to. They need the extra heat out of the engine. Thankyou EPA. The RX-7's were done mechanically rather than electronically. We used to disable them and just let the car take a little longer to warm up when cold. |
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Originally Posted by rotarygod
This is one of those issues that rotaries have always been set up to do. However it doesn't mean it's good for the engine. It isn't. When you first start a cold engine you don't really have an oil up in the engine. It's mostly in the pan. You start it and it takes a few seconds for the oil to reach every passage and bearing. It definitely isn't a good idea to spin the engine up faster right away during this period. It adds a small amount of wear to internal parts. The next thing is that you don't want the engine heating up too quickly as we have staggered cast iron and then aluminum housings which expand differently with temperature changes.
So why then does Mazda do this? Emissions! That's right, an environmentalist beaurocrat somewhere had enough of a say that it affects the longterm wear of your engine! Emissions standards say that your cat has to do it's job within so many seconds of starting. It can't do this when it's cold though so they need to heat it up as fast as possible but still slow enough not to kill the engine. A little wear is fine apparently. The engine revs up higher when it's colder because the cat has a greater temperature range to heat up to. They need the extra heat out of the engine. Thankyou EPA. The RX-7's were done mechanically rather than electronically. We used to disable them and just let the car take a little longer to warm up when cold. |
Weve been having very cold days and nights here in cincy and I started my car up on tuesday and it was about 3degrees that morning and it went to 3500 and started revving itself for about 15-20secs. My car was in neutral and I was outside of the car drinking some coffee and talking with my neibor. I havent seen that before ever! Just curious if that revving by itself is normal or not.
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Originally Posted by t-run/8
That's intersting. I might like to try putting a space heater near the cat, remove it in the morning, and see how the engine revs as opposed to no heater.
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sounds like the general concensus is that it is normal, but not good for your car.
WTF is wrong with this picture. :mad: Anyone know any way to limit the revs, or cut them shorter? Sounds like blipping the gas might help a hair...but I'm just not content watchin my car helplessly rev itself away in the friction-heavy, freezing cold environment. I guess i'm just mostly suprised that it hasn't bothered more than it already has |
Tapping the gas pedal drops the revs to 2k as another poster pointed out. While it's still a little high, it's not nearly as bad as 4k.
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Originally Posted by Stavesacre21
sounds like the general concensus is that it is normal, but not good for your car.
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I never questioned if general cold starts were bad for your car, I simply was questioning 4K RPM starts on an ice-cold engine. There is a difference.
Next time you start up your 8 and it races half way up the tach like your slamming the gas down, see if you raise any concerns. and I already store one car...don't need another. |
yup, i had the same initial reaction as well when i started her up for the first time in sub-zero conditions.
i was like WTF?! lol panic mode, but it is normal. the colder it is the initial RPM will be high, but it does go down to 2500-3000rpms and then the tach will start to rev itself and bounce around for a while until it warms up a bit. usually takes 5 minutes or so for it to idle down at 1500rpms. I good investment is an oil pan heater? at night you just run an extension cord out and plug it in to the oil pan heater and you'll be good go to in the morning! highly recommended. |
yea i've never had a problem with a cold start from the garage...it's when i come out and my car is either in a lot or in the parking garage at the hospital...places where a heater clearly wouldn't be feasable.
I did however try the tap the gas meathod and it is tried and true...just blip it and it'll drop on down to around 2. Ahhh...that's much better :-) |
Yes, this happens 4-6 times a winter for me. It happened the first time this winter a few weeks back.
I even have a video of it going from 3600 down to 2300 and then down to 1500. Just let the clutch out as soon as you can, because that drops the revs a little. EDIT: Ah, just read about the throttle blip thing.. good idea. Also, I wouldn't worry about the wear to the engine--these RPMs are really not all that high (Mazda revlimits the car to 6500 when cold), and there is no load, and it happens only for a short amount of time. |
I just started having this 'issue'...and I noticed blipping the throttle did bring the revs down.
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Originally Posted by Stavesacre21
I never questioned if general cold starts were bad for your car, I simply was questioning 4K RPM starts on an ice-cold engine. There is a difference.
Next time you start up your 8 and it races half way up the tach like your slamming the gas down, see if you raise any concerns. and I already store one car...don't need another. Just a thought. |
Originally Posted by Endor
It's not "good" but the number of times you're starting your car in these kinds of conditions is very small compared to the overall life of your car. If you're that worried about damaging your engine then park it for the winter or move to Florida or SoCal. Otherwise just accept it as part of owning any car, rotary or otherwise. Starting a piston engine is going to be just as hard on the internals as it will on your car.
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Fuck Emissions And US Regulations
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