Sudden High Idleing.......

[Rabbi]

I ran my car for a good 4 hours yesterday testing for more problems (this car has been an ongoing project)

 

the car ran perfectly idling for over 4 hours without overheating or smoking (good sign finally!)

 

today i go and start it up and the dam car idles at 2000 rpms in park & neutral. But as soon as its popped into any gear including reverse the rpm's drop down to around 1K like they should be.

 

What could cause this? The car was running perfectly yesterday now its running like poo again.

 

 

Also ive noticed im losing alot of antifreeze yet its not leaking anywhere, And i opened my radiator cap today and the stuff bubbled out like ive never seen before, Almost like it was boiling after running the car for about 3 minutes.....Im thinking my radiator is fucked also, Shouldnt my radiator be warm to the touch after 4 hours of idling? The radiator is always freezing cold, But my fans do kick on after awhile like they should. Is my radiator shot?? Could this cause high idling in park & neutral?

[19Cutlass94]

What motor is this on? If I was loosing coolant and there where no puddles anywhere, Id be tearing into that motor to replace the LIM gasket pretty quickly. Since we all know bearings dont get along with coolant. Take off your oil cap and look and see if you can see any milky substance. If so Id replace them with no hesitation. If not, maybe it hasnt gotten that bad yet.

 

As far as the high idle goes, Id look into the IAC. You will probably need to do an idle re-learn to fix that.

[Rabbi]

this is on a 91 z34 with the 3.4.

 

I have a feeling the coolent is leaking but im not 100% positive, The oil looks fresh as hell but the motor does seem to get unusually hot very quickly. And i dont think the coolent is circulating like it should be, Shouldnt the radiator be hot as shit after running for 4 hours? The idle problem just started today after running fine for months. But ive always been concerned about the radiator not getting even slightly warm....Its ice cold after idling for 3-4 hours in my driveway, That isnt normal is it?

 

Also the car idles in park at around 1.5 to 2.0 thousand rpm's but seems to drop a tad after a few minutes of running.. I screwed with my alarm system last night because it wasnt working but i dont think that would effect the idle would it? Im trying an idle relearn right now so i will post the results later tonight.

 

The engine gets extremly hot very quickly but no signs of overheating, The gauge shows the engine just over the middle normal white line so i dont think its overheating, But the motor is VERY hot very quickly, Even the side braces (almost look like strut braces) are even hot as hell. The entire engine compartment is just hot as hell to the touch, But theres no smoke or overheating signs.....Im leaning on just selling the car but if its something simple id like to hold on to it if i could.

[Rabbi]

ttt

[joey b]

when in gear and driving, what speed does it idle at?

[Rabbi]

900-1000ish

[joey b]

in MPH, trying to figure out if the idle speed drops due to being in gear or due to the transmission not allowing it to rev any higher.

[Rabbi]

in MPH, trying to figure out if the idle speed drops due to being in gear or due to the transmission not allowing it to rev any higher.

 

im not sure exact mph,it doesnt seem to be hitting any sort of rev limiter

[THe_DeTAiL3R]

High idle could be a vacuum leak...

[joey b]

put it in drive on a flat surface, let it roll without your foot on the brake or gas and tell me what speed it goes. I don't see why it would run normal in gear but not out of gear.

[fastbird232]

IAC maybe?