Taknitez

A few weeks ago, I noticed a knock/tick/pinging like noise around the 1800-2000 rpm (driving with a light foot on the accelerator) mark while running BP 87 octane. Never had this problem before, car always ran fine-smooth-quiet. It seemed to do it more with the a/c on and really more in the morning when first starting out for the day for about the first 10-15 minutes of driving.

After taking it to my trusted service tech at Scion, he told me a few different models of Toyotas are notorious for this around that RPM range. He mentioned a few Toyota Truck models as well.

He had me run a tank of 93, and then two more tanks of 93 with their special "$20 a can" cleaner that they use for such a thing. And now, on the ''fourth tank of 93", I still have this knock/tick/ping like noise even "without" the a/c on at the 1800-2000 rpm range for the first 10-15 minutes of driving in my day and almost the whole time when the a/c is on. Again, this is driving with a light foot. Also, I have 17,000 miles on the car.

Do I need to get the spark plugs and fuel filter changed? Is their gap all of a sudden off? Is the ECU messed up? Is is the "summer gas blends"? Maybe it is a "valve" thing that maybe they started by using a different grade of oil at the last oil change at the Scion dealer--I'm not sure they changed the blend ( you know, say 10w40 vs. 20w50) , but could something like that cause what I am talking about?

Or is this just a true thing on how it is with Toyota engines?

Remember, all is well except in that exact range (1800-2000 rpm,,,driving lightly)...usually for the first 15-20 minutes of driving with a/c off and now almost , almost always with the a/c on.

Please help...this is driving me nuts!

pandaslayer

You should'nt be knocking since our engines have a built in knock sensor and retard to timing when something happens.

Taknitez

"Exactly right"....that is why I have put this post on here. I need help on what to do /or what do you all think is going on.

thanks''

kevets

out of curiosity... why run 93 octane?

pandaslayer

Well you might have a faulty sensor, since now you're hearing the knock and pings. See if you're throwing and codes. take your car to Auto Zone or hatever, and they can tell you for free if you are.

sixpac440

Take it to another dealer. It should never do this.

Modern engines have sensors that adjust for variations in gas quality, octane rating, engine load ECT. “Your trusted” mechanic is wrong and you are slowly ruining your engine every time you hear the knocking.

This is a no brainier as it’s a warranty problem.

grizzly_choppers

Um, you're still under warranty. Take it in and have it fixed. You do not require 93 octane fuel unless you have forced induction or some other compression-increasing mod that you haven't mentioned.

In any case, take it in and have it fixed. That's the beauty of warranty.

-Alex

bB2NER

Take it to a different dealer and let them change out the knock sensor. Get the first one to refund the money you wasted on the 93 fuel. Also quit using BP gas. I use Shell 87 with zero problems after 2 years and 30K.
I'd also call Scion corp and let them know what the first dealers idea for a fix was.

Taknitez

I called another dealer. The service guy there said that it is "not" the knock sensor since my "check engine" light is not "on". He said as long as it is not on, then the knock sensor is performing as it should and they will not replace it.

He did tell me to try another brand of good gasoline such as Exxon or Mobil...etc....since it could be the type of "detergents" that BP may be using.

Does this sound right to you all as to what he said and what he thought about the gas and knock sensor??

Oh, and I do not have any engine modifications what-so-ever. Completely stock set-up.

thanks'''

YourNameHere

is the engine warm yet? mine acts weird sometimes until the temp light turns off.

GAWBoX

I have had this same problem with my box for a while -- this is the first post I've seen that has the same symptoms as mine.

The key that I saw was pandaslayer's mention of the knock sensor. I looked up the TSBs on infortraxx and found TSB EG039-04, Here's what is says:

"MIL ON DTC P0325 - KNOCK SENSOR"

This applies to the Echo, xA and xB. I am too cheap to pay for the details of the TSB, but I'm thinking there may be some basis for you to think there is a problem with the knock sensor.

Essentially, you and I have a problem with our timing that may be due to a faulty sensor. I'm gonna check this out with my dealer.

bB2NER

Just because it doesn't throw a code doesn't mean that the knock sensor can't be bad. It just means that the computer isn't picking up the problem.
Find out how much the knock sensor is. If it's not that much try replacing it. If it fixes the problem have Toyota reimburse you later.

pandaslayer

I think you should try and talk a deal with the dealer, to replace the knock sensor on your own dime. If it fixes the problem, they should refund you since it's under waranty.

zyton7

when i bought my xa the dealer told me to never use 93 octane or the octane boster/ fuel injector crap on the stock spark plugs cause it will burn them up.

vintage42

1. Knocking (pre-ignition) only wants to occur under high load, which you are not doing.
2. The engine has a knock sensor that retards ignition to stop knocking before you can hear it, and if the knock sensor was faulty, it would cause a trouble code, which you don't have.
3. The owners manual says that the knock sensor cannot prevent knocking on octane less than 87, but which you are not running.
From this I would think that you are not hearing a pre-ignition knock. You are probably hearing a noise from some other cause, and I would look for that before replacing the knock sensor (which is buried under the intake manifold).

vintage42

It avoids the knock sensor's retarding ignition when knocking is sensed under heavy load on 87 octane. The 2005 xB was rated at 108 hp and higher torque because tested on premium, vs the 2006 at 103 hp on 87.

grizzly_choppers

I repeat, take it in and have it fixed.

Play dumb when you take it in. Offer no suggestions about what the problem may be, just tell them what is happening symptoms wise and let them fix it. If you have not modified the engine it will 100% be covered under warranty.

-Alex

brambling

The TSB only recommends replacement if it throws code P0325.

An improved knock control sensor was put in production during 2005 for VIN JTLKT3#4#50190331 and later. Can you tell if yours were produced before?

vintage42

Aftermarket octane booster additives can cause problems with plugs and valves. I began using 93 as soon as the engine was broken in. Try a full tank of it and see if it feels like more power under full throttle. The 2005 engines were rated at 108 hp on it.

bB2NER

^^He said he already tried 4 tanks of 93 with no improvement in his first post.
IMHO I feel it's just a bad sensor or an ECU problem.