You guys really helped with my last question about a Jetta taking on water, so now I have one about my 2004 Corolla LE.
For a while now it has idled at very high RPMs when it is first started. It drops faster when the weather is warm, but even then it will idle around 1200-1500 RPMs for 2-3 minutes. This only occurs in Park and Neutral. When the car is in R, D, etc. the RPMs drop to around 800. Once the car is warm, the RPMs hang right around 1000.
This does not seem normal to me, but the mechanics just ignore me every time I bring it up. Any ideas. Just to add to the puzzle (for me at least) there is a lound tapping sound that comes from under the hood and drives me crazy. Today I finally hunted it down and to the best of my ability, it seems to be coming form the VSV for the EVAP system that is mounted on the air filter assembly. Do you think the two problems are related? Futhermore, do you think the tapping is the VSV and if so does that mean that it needs to be replaced?
There are no CELs and the car runs find otherwise. It does feel like it has less get up and go than it used to, but it is a corolla with nearly 70,000 miles on it. Thanks for the help with the last question, I look forward to investigating this futher.
The RPM issue is a non-issue. The ECM controls the idle speed and will set a trouble code if it is out of spec. Nothing so far sounds like it is a real problem just yet. Maybe cleaning the throttle body and IAC circuit will help, but not much else.
Also, there may be nothing wrong with the purge valve, just noisy. If there was a problem, the ECM would detect it and set a trouble code, turning on the CEL.
Also, your getting to the point where you need to consider changing the spark plugs and ignition wires if your car has them. This may help in the ‘get up and go’ dept. Many maintenance schedules call for changing at 100,000 miles, but I find that 60,000 miles is a better interval. By 100,000 miles, there’s barely anything left of the center electrode, and the engine is running pretty bad.
The specs that I can find suggest that an idle of 800 to 900 is the upper limit and at times my car is nearly twice that. While it may not be enough to set off a CEL, I do believe that it is too high and likely to reduce the life of my engine. I believe that something is not operating properly, though I am hard-pressed to offer a solution.
Why do you refer to the VSV as a purge valve? This is one of the problems I am running into as the manual calles it a VSV, but there seem to be so many other names that I cannot find a great deal about it only. The sound is quite loud too, I can easily hear it with the hood closed and when the car is idling at 1400 RPM.
Your idle is fine. These 1.8 liter engines can idle above 2k rpm on cold mornings and it is normal. The tapping sound you are hearing is also a common complaint, but it too is normal. I am a tech at a Toyota dealership. My best advice is to stop listening so hard waiting for there to be a problem, just drive until the car tells you it has a problem, it will.
I recently changed the plugs in my Corolla at 100,000 miles (owners manual says 120,000 miles!). The irridium plugs looked nearly new with only a tiny deposit on the grounded electrode that appeared to be metal transferred from the center electrode. The gap was still on spec and the engine was running perfectly. There was no detectable change with the new plugs.
Thanks for the advice everyone. I guess I will try to stop listening so hard and relax.
Might want to check the engine coolant sensor. The car may not belive it is warmed up when it should. This sensor will not set a code till it simply does not work and it may save a bit of gas.