10th Nov 2005, 11:38

Mine has a 3.4 and knocks as well. I've found that using a higher octane like 93 octane gas eliminates the knocking. Ive been told this is due to a sensor that is stuck which compensates for the octane differences. Id recommend trying Ultimate gas until you can get it fixed.

16th Feb 2006, 12:57

Good on-road, but don't push it off. Car-like component that will wear fast and cost you a fortune. V6 suffer oil starvation when incline off-road. Basicaly an on-road vehicule and an overestimated suv.

3rd Apr 2006, 23:58

If your warranty is over, Toyota will be happy to do it at the full price. But I recommend an AAA certified shop that knows about used Toyota engine rebuilt since Toyota's mechanics are like maytag under warranty technician.

8th Nov 2006, 13:19

The sensor that is causing this knocking is called - funny enough- a knock sensor. I have a 1991 4runner, and had to have mine replaced about 2 months ago. All it is, is a computer chip on a bolt that is inside of your engine. It measures the amount of mixture of gas and oxygen your vehicle needs to accelerate. (I'm guessing you probably don't have a lot of power either.) The sensor itself for the 1991 cost me $170, and there are a variety of gaskets that go along with this including your EGR gasket. Labor is what you will be paying for the most, because nothing is easy to get to in a Toyota. To get it fixed, you're looking at spending around $500-$600.

1st Jan 2007, 21:09

For starters, a Knock Sensor does not measure the octane and oxygen mixture. This sensor detects detonation or pre-ignition which is where the KNOCK comes from. When the sensor detects a knock, the computer will retard the ignition timing to reduce detonation. This is definitely something that should not be overlooked as repeated detonation can result in engine damage. If your timing is correct, fuel is of good grade, engine oil pressure is OK, than there is the possibility of collapsed piston or I have also seen a chip out of a valve lifter that created a light knocking as well. If it was mine it would probably just get driven if all the above minor tests proved OK.

21st Jan 2007, 19:32

My family just got a 1999 toyota 4 runner with 170k miles and none of the Gauges are illuminated. We are wondering if this is normal like in the older jeeps or if there is something wrong with the Lights. None of the swithches are lit either. The only ones that are, are the ones for the windows. They don't appear like they are meant to be illuminated, but it seems strange for such a modern SUV.

21st Aug 2008, 17:57

1997 4Runner 3.4L V6 that pings bad at lower RPMs upon acceleration with most 87 Octane gas. Now that most gas has 10% ethanol the ping has gotten worse, I though it would get better since most ethanol has a higher octane rating. Dealership and reliable mechanics have told me to run higher octane fuel and it does resolve issue. One mechanic did indicate that the "knock sensor" could be sticking so I used Seafoam in the engine and it has reduced the ping but it is not gone. Seafoam has allowed the engine to run on 89 octane with minimal ping. Even with gas prices the way they are just paying a few dollars more per tank for higher octane fuel is much cheaper than a $500-600 knock sensor replacement that may or many not fix the ping.

17th Nov 2008, 10:40

1997 3.4L V6 136,000 miles that knocks on acceleration that has gotten worse since all the fuel in my area of Florida is 10% Ethanol.

Higher octane fuel works, but the vehicle does runs best on Chevron fuels, even their 87 octane. I am not going to spend $500+ for a knock sensor and neither the dealer or local repair shops say it will make much difference. Run better fuels and/or higher octane fuels or find another vehicle, but since I am not at 250,000 miles yet I am going to keep her.

3rd May 2009, 00:22

I have driven a 2001 Toyota Tacoma 4 cylinder and a 2003 Toyota Tacoma V6, and both have made pinging/knocking noises while accelerating from low rpms. Mid grade gas and premium gas seem to help, if not eliminate the noises. I assume this is characteristic of these Toyota engines.

17th Dec 2009, 20:16

The knocking is not gasoline related or a combustion problem. If this is a knocking similar in sounding to valve tick, and that's been ruled out, then bearings could be the issues. And no not wheel bearings. Check out the fan bearings or belt bearings...

30th Dec 2010, 10:38

I have had problems with the car ever since I bought it. My transmission had oil get mixed in, and after I had it fixed, now my transmission is gone... Will never buy a 4Runner.

21st Nov 2013, 17:19

I have a 99 Toyota Tacoma that has a knock in the top end that gets faster as the RPM increases. What could it be? Lifters?

22nd Nov 2013, 06:57

Try 93 octane. Cheaper than an engine rebuild is my thought.

22nd Nov 2013, 14:35

I have a 96 Tacoma and it's always made a tapping sound up top. These are sort of noisy engines for some reason. Never caused a problem for me.