4250 RPM idle at startup in bitter cold
 

Started up the 8 this morning - it was about 11 degrees F outside. The RPMs immediately rushed up to over 4000 RPM and held there for what seemed like forever (probably only 15 seconds or so though). I hadn't touched the throttle prior to startup. It then dropped to just over 2000 RPM and held there for the remainder of an extended warmup. Car not only ran OK after that, it ran very well, seemed strong.

When I shut the car down yesterday afternoon it was idling at about 800 RPMs, as is typical when my car's warmed up.

I don't recall reading anything like this on the forum before. Since I don't usually reach 4K RPM till the car's been fully warm for a few minutes, 4K+ at ice-cold startup gave me quite a scare.

Anyone else have anything similar happen to them? Any ideas whether this is normal?

Thanks.

At least it stayed running. Everytime the temp drops below 20F, my engine will die right after start up unless I either leave the clutch pushed in for about 30 seconds or blip the throttle a couple times.

Common occurance up here in Canada. There is a post or 2 on this.

Thanks for the input. My searches showed lots of folks who saw 2500 or 3000 rpm idles but looks like I've still got the record. There was also lots of examples of surging, where my idle was steady.

11 deg F = bitter cold? Heh heh. It was minus 33 C (-27 F) here this morning. Has been like that all month. But seriously, 4250 rpm is kinda scary. Never seen anything like that . . . so far. Good luck.

bitter cold to some, heat wave to others... :)

My guess is this is normal. A call into your dealer service Manager should confirm this. It rarely gets super cold in Texas, my 8 has not climbed that high at start-up, but it does get up there.

Good luck!!

- Irish :cool:

You should get a little better performance when you got nice cold air.

My car did almost the same thing one day that was about 9 degrees F. RPMs rushed to 4000+ but quickly dropped down to 2000 and then stayed there for a good 10 seconds or so. Normally, RPMs start at 2000 and then quickly drop down to 1500 or so.

We've only had one really (relatively) cold day where I live, so I don't know yet if this will be a common occurrence for me.

Revto9K, here is the link I was talking about. Someguy went higher than 4.5K!

https://www.rx8club.com/showthread.php?t=48056

When my engine's real cold, it seems to want to go back and forth between 2000 and regular idle 3 or 4 times before it "settles" down. It's kinda scary, cause when it hits that lower end rpms, it almost sounds like the engine wants to shut down. Once I've sat 10-20 seconds, it's all good.

Even on mornings when it was close to 0 or below, my 8 never hit that high on the tach. Usually would go to about 2500 for a few seconds, then settle in at about 1250 and then gradually decrease to it's normal 750 when completely warm. It is garaged for the rest of winter, so I don't have to worry about it any more for a while.

Yes RevTo9K, I had something similar happen. (see thread) https://www.rx8club.com/showthread.p...light=3600+rpm

A couple days ago the temp was around 0 and this didn't happen, but the high to low idle RPM oscillations did. I don't know if this was due to the reprogramming, or just coincidence. Anyway, I still think the high RPM on a stone-cold engine can't be good for it!

There is a similar thread in the Canadian forum where the engine burps the gas for 5 minutes before picking an idle.

https://www.rx8club.com/canada-forum-35/does-your-car-do-very-cold-49949/

Mine , when its started runs up to 2000 rpms then down to about 1500 rpms , then after about a minute ,it runs up to 2000 again then starts bringing the rpms down

Hey everybody,
Thanks for the input, the links, etc. This morning it was even MORE bitterly cold - about 3 degrees F (or for those of you north of the border, picnic weather :) ). Only went up to 3500 Rs and then dropped to 2000 rather quickly.
...and as djseto pointed out, the car runs very strong on ice cold air.

My car is parked outside, I get the same exact thing.

The last few days, its been around 0 F when I leave in the morning. This has easily been the coldest few days since I've had my car, and I also freaked out a little when the rpms went up to a little over 4000 when I started the car. The RPMs went down pretty quickly and I kind of figured it was just because of the cold. I agree the car does seem to run very well in the cold air, but the cold is also murder on the already poor gas mileage.

Yeah, really... the idling sure doesn't help. Plus, when it's running that nice, it's hard to keep outta the throttle.

Hey guys,

first time poster, long time lurker. Thought I start posting and hope to contribute to the forum.

I had the same problem this morning. i was surprise to see the RPM rocket up to around 4k, however mine started dropping after a few seconds. Went down to 2k, then down to 1k. I thought the car was going to stall or something so I revved the engine a few time, but then it finally settled around the normal 800 rpm range.

And yeah, the car seemed to run much better more quickly than my other days trying to warm up the car. Strange isn't it?? :p

Rotary Owners Don't worry! A piston engine can have piston damage by high rpm with a cold engine as the piston is smaller and slams around a lot. But the rotor is not soft aluminun and their really is nothing that can be damaged except for the lack of oil on the bearings. Also low RPM ,when cold, will cause "fretting" as the different materials expand and contract with each power stroke and cold water shock. So reving the engine gets the oil moving faster (if using the correct oil) and actually has less time between each power stroke to have the thermal expanion. Mazda learned this back in the early 70's as the short distance drivers were the ones having the "O" ring between the housing burned and failing. Starting in 1974 this ring was teflon coated to prevent the burning. Also reving helps the exhaust system and converter get warm faster so the smog emisions are eliminated.

Even with the 32F it's been the past morning start up has been normal. So I didn't have this exact problem, but something else cold related.

Two days running, it was below 32F (in Florida here). Started her up, backed out and drove down the street. No problems until I accelerated away from the stop sign.

When the engine is cold, I don't usually rev high, but I did by accident and this happened:

In 1st I accelerated, and at 5,500 RPM it seemed like it bounced off a limiter (like it would at redline). I repeated the experiment a couple of times in 2nd and 3rd thinking I had either not been watching the guage, or accidentaly put in the cluth or something. But sure enough, bounced off of 5,500.

After the first 10/15 minutes, the temp guage finally moved up past "C", gave it a rev and it went above 5500. Weird. Tried again at lunch, after it was warm, gave it a few "experimental" high revs to the warning buzzer, so it's not in limp mode either.

Anyone else, especially in colder parts get this?

I havent seen this posted before, not sure what to look it up under with the owners manual, so no yelling at me! ;)

That is in the owners manual. 4000 is OK to get the oil and all moving, but 5500+ is too much so there is a limiter built in. I have hit it also and it is a shock.

hrmm, must have missed that chapter..., probably cause I figured "gee I'm in florida..."

I assumed it was a feature not a gripe, just wasn't sure. thanx

We had -13C/-5F this morning in Toronto and my car did the 4250RPM spike at start up and then eased down. Damn I hate it when it does that! It makes me nervous. But I tell you, the car drives really great/peppy and smooth after that!