kaneda3

this is what happened to me on my 10 minute drive to work

keep in mind this is a 90 si hatch with a b18b and turbo
and it was 7 degrees outside normally my car runs really cold(according to temp guage) and it will idle pretty high until it warms up (1500 rpm)

well i stop at a light and my rpm's start jumping from 1000-2500 over and over while at idle so assumed my idle control valve went on me
got to work parked it figured i would deal with it when i got home

so i leave work get in the car and everything is normal again
half way home i realize that the vents are blowing nothing but ice cold air
and i notice my temp guage is slowly rising
its idling fine now but my hands are still numb from the drive

any ideas?
could it be my water pump?
does that have any affect on my heater please let me know
mike

Speed Phreak

Could be a few things. You're idle fluxing and you're getting cold air with your heat on.....Interesting.

Could be the IAC (Idle Air Control) Valve like you said. Have you checked the cooling system yet? You just have some air in system, that could account for the funky idle. If you didn't have enough water in the system at all, you won't get hot air out of the heater either.

How high did your temp gauge get? Was it way up like overheating or just in the normal range.

inspyral

Do you hear any strange noises from around the timing belt cover(water pump)?

kaneda3

it was seriously below 0 with the wind chill so i didnt even get a chance to pop my hood(no garage)

it was on its way to over heating but i didnt spend to much time driving after it started rising

ill have to check my fluid tomorrow

thanx guys
mike

inspyral

My guess would be the water pump, or something else obstructing coolant flow, since it's not getting to your heater core, and and the fact that you were overheating.

vermsta

High idle on start up is normal. Your supposed to be around 1300 rpms I believe, all though depending on the coolant temp sensor signal it will vary, like if your coolant temp sensor is saying it's really cold then it will idle a little higher in order to warm up your engine. Now the fact that your heater all of a sudden wouldn't blow any hot air, just makes you suspect a cooling system problem even more. If your low on coolant or your heater core blew up you won't get hot air through. Now if your really low on coolant you may not even be getting any coolant flowing by your coolant temp sensor which is making your idle out of whack, but usually if you have a flucation in the idle it's due to whacky signals or something making your idle air control valve stick. One thing to check is a vacuum leak, which I believe vacuum is what changes your thermostat in your cabin from hot to cold, actually you might want to disregard that because i'm not really that knowledgable about heating and air conditioning. First check your coolant level if that's okay you can rule that out. Then after letting your car reach normal operating temp check your upper radiator hose make sure it is hot, if not your thermostat isn't opening. While doing this you can leave your radiator cap off and watch the coolant flow through the radiator if you never see movement once the cooling fans coming on and the upper radiator hose gets hot then suspect the water pump.

vermsta

Also there is coolant hoses going to the fast idle vavle? Not sure if that's what it's called. Just another thing to keep in mind.

inspyral

You're probably thinking of the IACV.

MrFatbooty

There's the fast idle thermo valve which uses a thermowax plunger in the coolant to bring the idle speed up when coolant temp is low. If the coolant line around there is busted you would have the not warming up problem and also the jumpy idle problem. The valve has a port running into the throttle body and it's pretty close to the IACV.

kaneda3

ok heres the deal

one the coolant is full

two the upper hose is not getting hot

and three i dont see the coolent moving either

so i should assume its the water pump?
is there any other possibiltys before i order the part and ask my friend to help install it?

do i have any aftermarket options with a new water pump or should i just stick with oem?

thanx guys youve been a big help
mike