Detonation?

My 01 with the 3.4 runs great for 133,000 on it but under load around 1900 rpm when I'm accelerating I get a little sound like detonation. I run midgrade gas and new plugs and wires. Anybody have some ideas on this. I did just put slightly over sized tires on too. Thanks

 

The knock sensor is old. Unfortunately, I don't know a way to test them and it's not easy to just change and see.

You should be able to run regular even at high altitude and the computer adjust whatever is needed but it could play a part. You don't have your location in your profile.

 

Oh... really? Ok, I will look into where it's at. I'm getting ready to do the whole timing belt/water pump anyway. Thanks for the input! Very much appreciated!
Jon

 

Fuel filter, air filter, etc?

What spark plugs are you running? The 3.4 hated iridiums when I put them in mine. The FSM requires dual tip ground electrodes. Run NGK or Denso dual tips?

 

I got the OEM dual electrode plugs from Toyota and gapped them to .43 as per specs. Fuel filter was just changed and air filter is a K&N. Another member on here said it might be the knock sensors are old. Not sure

 

I'm certainly not sure either but they ARE old. They are under the LOWER intake manifold making them hard to get to.

It also puts them in a high heat area and tends to make the wiring to them very brittle (and could possibly lead to resistance problems leading to the ECU......maybe, I think). Sometimes the wiring itself IS the issue but that's usually a go/no go.

If you're pretty good at wrenching (at least shade tree level) and think valve cover gaskets are next. (prob. are if not done already) you could tear off the whole top and front at one time, change lots of seals (they're all getting old, remember) and while at it get injectors cleaned up good to rule out (again, possible) lean issues from partially plugged injectors.

If this is a 2nd vehicle it's a nice project and most of this stuff will be done eventually anyway.

 

Unfortunately it's not a second vehicle but that may next after the timing belt which should be loads o'fun!

 

Timing belts are easy on these, everything is staring you in the face. Look for a Timmah toolman vid or others. It'll help.

You could try burning a tank of really good gas packed with Techron and see if carbon buildup on parts is a problem.

Unless you use an additive regularly already, then it's unlikely.

 

Yes sir! Timmah! has been very helpful! Sent me videos and tips. Really helpful

 

Pinging seems a common problem.. I have followed other threads and the only decisive one involved cleaning out the intake manifold ports and replacing the injectors, but that was with a 4 banger. I don't know if a knock sensor will help, as it will throw a code (this is hearsay) if it is going bad. So it's not a part that you need to replace unless it tells you. That being said, swapping the knock sensor sounds like a band aid fix, and what needs to happen is the gunk needs to be removed.

 

I agree with thunder One on this as and he could be right about a code. However, the intake would still have to come off to clean well.

Once that far, I don't know if I'd button it back up w/o a new knock sensor since having det. probs. beforehand.

Dam if you do................