2001 Corolla S - Automatic - NO SMOOTH SHIFT after replacing SPARK PLUG - Toyota Nation Forum : Toyota Car and Truck Forums

rkweb · 11-09-2011, 12:21 PM

Hi all,

Reg: 2001 Corolla S - Automatic with 115K miles

Two weeks ago, I had a known mechanic replace Spark Plugs, Transmission Fluid (drain and fill) and Brake Pads (Front) all in one service.

He replaced with below brand parts, since then I am experiencing Rough shift, other words small jerk/pull when transmission is shifting in lower shifts, and reduced mileage now (almost 50 to 60 miles drop)

Denso SK16R11 Iridium Spark Plug - 4 Count
Toyota Brand transmission fluid dexron iii - 4 Qauarts
Monroe DX741 Dynamic Premium Brake Pad

Not sure what could be wrong causing this change in car condition. OLD Spark plug he pulled out was NGK brand. I am suspecting about the Spark plug and trying NGK brand. Please help me out on this decision.

***REN69*** · 11-09-2011, 08:35 PM

the mileage could be from improper gapping on the spark plugs... the oil change probably freed up the gunk and created the rough shifting.

ilovecorollale · 11-09-2011, 10:51 PM

Could be spark plugs gap(.043 or .044), spark plug loose, too much tranny fluid or mechanic broke or did something wrong?

Bernie3 · 11-12-2011, 10:40 AM

It could very well be that something got jarred while doing the repairs. Look for loose or unconnected hoses, electrical wiring, etc.

You should have a 90 day parts and labor guarantee on all the work done. Take the car back and stand your ground. Be sure not to approve any other new work you might get charged for.

rkweb · 11-12-2011, 04:22 PM

Throttle cable issue was noticed 6 months ago. Throttle cable comes out when gas pedal is pressed down but it does not go back in, as it suppose to. Mechanic told me, when he did the spark plug replacement /tranny fluid drain/fill, he also applied WD40 to make the cable smooth and it will go back in once after gas pedal is released, Mileage has come down almost 60 miles per tank. Killing me.

Not sure this cable problem may be the cause for sluggishness and making rough shift.

My throttle cable problem is exactly showed in this you tube video below.

You Tube

pdq · 11-14-2011, 10:06 AM

Yes, either your kickdown cable is frayed or the return spring is bad. I just checked mine and it has lots of return tension on the cable when it is released.

I'd get that fixed/replaced first before looking into anything else.

landphil · 11-14-2011, 02:13 PM

As pdq said, start with the obvious. Another thought would be a front caliper sticking, another thing to check if the kick-down cable doesn't cure-all.

That will cause quicker, harsher shifts, and will delay or keep the transmission from upshifting into 4th (assuming it's a 4 speed) which will explain your loss of fuel milage.