Startup RPM vs Engine Wear?

[TheLoneRanger]

I still have the Explorer with the high start-up idle spike, now with 25K more miles on it, with no ill effects so far.

I did modify the IAC by restricting the airflow slightly. This dropped the 'spike' by about 200 rpm, and I don't grit my teeth anymore.

quote:

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since the needle sweeps all the way to the redline when you first start it up (all the gauges sweep to their maximum then down again)

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Patman, now that is SCARY.....!

(I love Vettes, wish I had one of my 59's back.)

[ May 29, 2005, 11:17 PM: Message edited by: TheLoneRanger ]

 

[Patman]

Only the needle itself sweeps up to the redline though, the actual rpm of the engine doesn't, then it would be scary!

 

[moribundman]

I've never seen my Audi's idle exceed 1k RPM during a cold start at freezing temperatures. Hot idle RPM is between 640 and 680 RPM, which is much lower than the hot idle in the same car with the Euro spec ECU, which is about 850 RPM. If it's not freezing my engine idles for a few seconds a bit over 700 RPM, then drops right away to between 640 and 680.

My old Scirocco would start at about 1200 RPM (gas pedal pressed twice before starting) in sub-freezing temperatures, but the idle speed would drop quickly to standard 920 RPM.

[ May 31, 2005, 08:53 PM: Message edited by: moribundman ]

 

[99]

There's really no point in even discussing this. The computer controls the idle and puts it where it is programmed to. Period. There's nothing you can do about it unless you go in and remap the idle parameters. Considering the car manufacturers have to warranty these engines, I highly doubt the momentary high idle after a cold start is killing your engine. I'd worry more about beating the **** out of it before it warms up or driving the car hard before it warms up...that's where you run the most risk of damage.