Again: Low Idle and IAC valve
02-20-2006 | 02:11 PM
#1
Thread Starter
Three Wheelin'
Joined: May 2000
Posts: 1,594
Likes: 5
From: Bayside, NY
Again: Low Idle and IAC valve
Hi,
My car's idle has been pissing me off lately. If I drive for a bit and shut off/restart the engine, the rpm's jump up to about 1200 and drop to 300 or so. Sometimes the car will stall. If I give it gas, the engine will rev up but drop back down to that mark. This has been happening for the longest time now (about 5 years). The dealer was never been able to diagnose this. I've been reading threads and it looks like people who have replaced their IAC valve have managed to get rid of this problem. Anyone know how much this thing costs and how simple it is to replace? Where is it anyway?
Another thing, sometimes when driving, I notice the car has very little power and it is not consistent accross the rpm range. I'm not talking about full throttle acceleration - just from 1000 - 3000 rpms. Other times (very rarely), the car has a lot of power (which is what I remember it as having when I bought the car). This leads me to believe that there's something wrong with one or more of the cylinders such as improper airflow or it's not firing right. Could the IAC valve have anything to do with this? Sometimes I can hear knocking coming from the engine (I have never used anything but 93 octane). The knocking is especially noticable when starting up a cold engine and driving within 30 seconds of starting it. At this point, it sounds like there is something really wrong with the engine. I've never heard an engine make such weird noises. I'm not even going to bother taking it to the dealer to have it checked out since they never find anything and I'll have to pay at least 80 bucks just for them to diagnose it.
Any help is appreciated.
Cheers,
Roshan
My car's idle has been pissing me off lately. If I drive for a bit and shut off/restart the engine, the rpm's jump up to about 1200 and drop to 300 or so. Sometimes the car will stall. If I give it gas, the engine will rev up but drop back down to that mark. This has been happening for the longest time now (about 5 years). The dealer was never been able to diagnose this. I've been reading threads and it looks like people who have replaced their IAC valve have managed to get rid of this problem. Anyone know how much this thing costs and how simple it is to replace? Where is it anyway?
Another thing, sometimes when driving, I notice the car has very little power and it is not consistent accross the rpm range. I'm not talking about full throttle acceleration - just from 1000 - 3000 rpms. Other times (very rarely), the car has a lot of power (which is what I remember it as having when I bought the car). This leads me to believe that there's something wrong with one or more of the cylinders such as improper airflow or it's not firing right. Could the IAC valve have anything to do with this? Sometimes I can hear knocking coming from the engine (I have never used anything but 93 octane). The knocking is especially noticable when starting up a cold engine and driving within 30 seconds of starting it. At this point, it sounds like there is something really wrong with the engine. I've never heard an engine make such weird noises. I'm not even going to bother taking it to the dealer to have it checked out since they never find anything and I'll have to pay at least 80 bucks just for them to diagnose it.
Any help is appreciated.
Cheers,
Roshan
02-20-2006 | 03:16 PM
#3
Senior Moderator
Joined: Aug 2002
Posts: 81,383
Likes: 3,063
From: Appleton WI
well the idle issue is most likely the IAC. Very easy to replace. less than 150 to change your self and is on the throttle body.
as for your "lack of power" it may be that your just used to the car, fuel you use (not all 93 is the same) How many miles do you have? it may be time for a cange of plugs.
As for the knocking, it may not be the engine. there are acouple causes that could be making that. 1). could be the purge control selonoid (common for making the ticking sound on this car) 2). could be the evap canister behind the drivers side rear wheel. 3). could be a exhaust gasket. or 40. it could be the valves need adjusting (unlikely but possible)
If the dealer your bringing it to never finds a problem (very hard to do if its only hapening randomly or not throwing a code) try a Different dealer!
as for your "lack of power" it may be that your just used to the car, fuel you use (not all 93 is the same) How many miles do you have? it may be time for a cange of plugs.
As for the knocking, it may not be the engine. there are acouple causes that could be making that. 1). could be the purge control selonoid (common for making the ticking sound on this car) 2). could be the evap canister behind the drivers side rear wheel. 3). could be a exhaust gasket. or 40. it could be the valves need adjusting (unlikely but possible)
If the dealer your bringing it to never finds a problem (very hard to do if its only hapening randomly or not throwing a code) try a Different dealer!
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