Sometimes when my 5spd xB is at idle, the rpm's get a little crazy. I'll be sitting at a light, and the tach will start to drop until it shudders a little bit like it's going to stall, and then it jumps back to normal. It is really slight, but I just wanted to know if I should be concerned. My old VW used to do the same thing, especially with the AC on, but it was a piece of junk. should I be worried about the new car?
drew

it does that when the fan ( radiator ) turns on to cool the water/coolant down I guess...

Mine does the same thing. It has been mentioned before. It might have something to do with the AC compressor cycling on, but some report this happening even when the AC is off.

I will mention it at the first service. Toyota might issue an update on the engine software to fix it. Or they might not.

George

thanks for the info guys, i appreciate it!
drew

My car does it all the time when I have been running it a lil harder I dont ever use the A.C. so I dont think that is it. I have also noticed it doesnt do it just when the fan is on. Must be the cam gears....jk

nice name boxxlicker. I was thinkin of getting lvdabox for my lisence.

it happens to me too though only when the a/c is on

sounds like a pulley or engine problem.

I would suggest cleaning out your throttle body, but being that the car has low milage, Im assuming here, you shouldnt need it.


What you might want to do is check your alternator. Mine died last week, on my 240SX, and the idle was rough the entire way home the night it died...

Being as these cars are all new and what not, call the dealership and ask if there are any service bulletins regarding the issue...

I can pretty much guarantee that it is a bad (faulty from the factory probably) o2 sensor. At my garage this is the problem with 90% of the cars which come in with low idles. o2 sensors are cheap, and in most cases universal, so if you are too lazy to bring it up with your scion/toyota dealer, just go to pep boys and buy a bosch universal o2 sensor, switch it out, and be done with it. If that doesnt fix it, i'm guessing it has to do with your power current.

I am also noticing a problem with my idle speed. If I driving in stop and go traffic, especially when I stop at a light, the idle always seems to dip to about 400 rpm, or so, then it goes back to normal. And the is with the AC OFF! It repeats this cycle every 20 seconds or so. I have been worrying about it so much, I've started to time the cycles :idea:

I called Scion Support, and they said they were gonna bring this issue up with Toyota for a possible Maint. Bulliten. On my next oil change, I am going to have the o2 sensors checked out. I hate, hate, hate, erratic idle speeds. They have followed me from my Accord, to my Protege, and now to my XA.

DOH!

jr

i have the same problem too. is it a problem? i dont think it can be to big of a deal because the car never stalls.

make sure your fuel injector plugs are fully snapped in i had this problem on my other car for a while, i looked under the hood and one of the fuel injector plugs was barely pluged in , so i pluged it in and problem fixed, just check it out and see if that is the problem. it might be.

mine stabilized after i put the synthetic oil in. Now it is always steady :wink:

mine does the dropping idle thing too, i usually notice that the radiator fan seems to go on when this happens, i'm sure it's just hte extra strain on the electrical system that causes it - maybe a ground wire kit and a stonger aftermarket batttery would solve it?

Just pretend it doesn't happen and it will go away...

I noticed that problem also and started with a grounding kit it helped, and then I started adding ICE. I upgraded the battery to an Optima yellow top with a Hyper Ground voltage stabilizer. The lights and electronics seemed to be better but idle was slightly noticeable. I was able to get in on the K&N cold air intake sponsorship and replaced the AEM unit I ordered with the car; my idle has been stable since then. Not sure if all of the above made this work or just changing the intake. I want to say thanks again to James Yim from K&N who sponsored several of the Team Scion West cars. :D :D :D

i know on some cars the computer will alter the timing on the engine so that it will run rough to check if there is any knocking. Like the car is testing itself so u do not run into a bigger prob in the future. I dunno how that helped but its just a little piece of info. :wink:

i know on some cars the computer will alter the timing on the engine so that it will run rough to check if there is any knocking. Like the car is testing itself so u do not run into a bigger prob in the future. I dunno how that helped but its just a little piece of info. :wink:


Thanks for the tip. I'd love to believe that it was my car "testing itself," and not something else. But, I am going to check my Fuel injector plugs, grounding kit, and ask about synthetic oil, when I bring my car in for it's first oil change.

Like I said, it only does the idle drop, when I am in stop and go traffic.

Sometimes when my 5spd xB is at idle, the rpm's get a little crazy. I'll be sitting at a light, and the tach will start to drop until it shudders a little bit like it's going to stall, and then it jumps back to normal. It is really slight, but I just wanted to know if I should be concerned. My old VW used to do the same thing, especially with the AC on, but it was a piece of junk. should I be worried about the new car?
drew

I had the same problem..I found out it was the gas i was getting...I went to another gas station and it went away. I guess there are places with dirty gas. It runs clean now..Just note, i always get 87 octane..

Hope this helps.

i know this is an old thread- but my 2005 does this! has anyone had any luck at the dealership?

My 04 xB automatic does this too and so has many other cars I have driven. I assume its normal.

I can rule out the injector plugs or any other mechanical problems, especially O2 sensors. The check engine light would be on and you would have a misfire code or O2 sensor code (out of range , slow response,...etc.) The main idle control is the function of the ISC motor in the throttle body. The ECM recieves input from the crank position sensor and NE from the ignition system and sends a signal to the ISC (idle speed control) motor which varies the opening of an air bleed around the throttle plate to control idle speed. When an ISC motor fails the engine usually will stall. The most common cause of poor idle quality is fuel quality. Much gas today is oxygenated and basicly sucks. It can also be very hygrosopic (attracts moisture like a sponge) and also contain various amounts of diesel and other petroleum products (when they flush pipes or switch products at the refinery they don't throw that stuff away, it goes in the discount unleaded tank!). Try a brand name better quality fueland see if that helps, I dont think an oil will smooth out your idle either.~~~~~~~~~~~scott

Mine does the same also, 7k miles and I use synthetic oil. When at a light, sometimes itll somwhat fluctuate, go down, then up, down...u know. Seems as if quite a few people have this problem.....

don't know if I'd call it a problem. It seems to be pretty normal. I have 12,000 miles on my car now and it's never caused any issues, just something that I notice from time to time. I'm not worried about it anymore.

Toyota has a TSB dated 05-20-04 (EG012-04) that addresses rough or low engine ldle at a stop.

http://www.corollatoys.com/parts/scionTSB/EG012-04.htm

However, it is simply a readjustment of the throttle cable. It's an easy, no-tools check to see if your own car is in spec.

George