Hi,

I have a 2006 Scion TC with approx 36,000 miles on it.
Just the past month or so it has been idling much rougher than it used to, and it drives rougher too. What likely is the cause of this?
I'm taking it in later this week to get new brake pads, and I will mention this, but I'd rather go in with some ideas.

Thanks,
Shelly

 

when was the last time an oil change was done and weight?

 

check your oil like indy tc said. also check your air filter, and add a bottle of injector cleaner.

 

Check your spark plugs for any abnormalities. You could brush them off and reset the gap. But honestly, they should be fine at 36k but you never know.

 

I had my oil changed last at approx 32,000 miles. I had it done at the dealer I bought it at. I assume they used the correct "weight".
My air filter was replaced about a year ago also.
Should I get the oil change and then just see how it goes?

 

This is the fuel injector cleaner you need. Don't buy the crap you see at gas stations or pep boys.

http://www.mopar2u.com/bg44kfuelsys.html

 

No, it's dirty fuel injectors. This is what you do.

1- Get a bottle of BG Products 44K fuel cleaner (only one that works, and I've tried a lot!) to find a bg dealer who carries 44k here's a link http://www.bgfindashop.com/locator/index.php about $20 a can.

2- allow the fuel level to get below 1/4 tank
3- get funnel pour can of 44k into fuel tank and refill tank fully until the nozzle clicks off.
4- run the entire tank down to about 1/4 tank, refill.
5- get oil change after this, because 44k leaves a residue on the sides of the combustion chamber that mixes with the oil diluting it, best to get an oil change after you do this.

6- enjoy the results, you'll thank us!

 

hmmm but u are due for a change :D

 

Try cleaning your MAF sensor with some soft cloths. I had a rough idle as well and noticed my MAF sensor looked like it had ash on it. Try giving it a clean, and almost guaranteed you'll get a nicer idle.

 

x2

 

To upday from my previous post about the 44k fuel cleaner. Yes I do agree in addition to the 44k fuel cleaner, and the oil change afterwards, you should also clean the MAF sensor.

It's located on top of the air cleaner box. Do unplug the battery negative first, then remove the connector and two screws holding the MAF sensor to the air cleaner box.

There are two sensors, down the tube is what looks like dental floss, that's the MAF sensor, it detects air speed or (Mass Air Flow =MAF). The other amber looking bulb on the outside of that tube is the IAT or Idle Air Temperature. Between both of these they determine the density of the air entering the engine.

In english? Dirty sensor = bad data to the computer running the car = bad idle too

Go out to a auto parts store and buy this from CRC, found it on Partsamerica.com which is a parent company to Kragen, Schucks, Checker, Murrays and Advance Auto Parts. you can find it there

http://www.partsamerica.com/ProductD...egoryCode=3225

To clean: Use the CRC MAF Sensor cleaner
-spray gently all over the sensor, allow to air dry,
-mount maf sensor
-attach wiring harness
- reattach negative of battery


That should help you a lot too, some dealers won't clean these, just replace it. Well they're not cheap and why not clean it. Most of us have found it needs to be cleaned every 15,000 miles.

There ya go, those two things should help solve this. Thanks to HEYitzMEEE for reminding me of the MAF sensor getting dirty!

 

Yeah for sure no problem. I know some people might be against this, but seafoam really helped me engine a lot. Better throttle response, cleaner burns, smoother driving, and a way better idle. My idle use to feel like my car was about to stall, after some cleaning of the MAF and a treatment of seafoam, I think I just took my tC off of the dealership lot

 

is seafoaming the engine difficult to do?

 

I got an oil change & did the fuel cleaner thing & it's running smoother now. Thanks.

 

horah! We stumped the chumps! (reference to car talk)

 

hey good to hear! yeah usually that 44k needs to be done about every 15-20k miles on the tC. Just the way it is out there with the fuel injector nozzles getting smaller and gasoline isn't that "clean" no matter where you get it. The deposits always form on fuel injectors over time. Engineering does all sorts of research but they still can't stop it. oh well there's always 44k fuel cleaner

glad it's fixed for you! glad we could help!

 

thats good to hear! ihad a bad idle problem myself this week caused by my m.a.f. dying!! so afta gettin a new one and cleaning the throttle body and new plugs, my babys back to normal ....

**just watch out in the future man about idle problems bc it could be ur m.a.f. dude!!