thomas1

You know maybe you just have a bad wiring harness to the knocks sensor. The harness is real short and plugs in on the battery end of the engine. Maybe trying unplugging and plugging it back in...however the connector are quite good on the Lexus, so chances are the plug is oK. I replaced the intake manifold gaskets for a water leak, and was right there at the knock sensors. The worst part was the lousey 14mm bolt on the back of the air plenum for the intake manifold...good luck

lexus114

Well, actually I was thinking on the terms of him having to bite the bullet. And take her in for repair. So their is hope my friend`s.

blueridge

Thanks for the tips everyone. I've tried various easier projects such as: Disconnect battery for 30 min, various gas companies and grades, etc and the code is coming up more often now.

Looks like a hard failure, before start tearing into it, or drop $866 of my transmission savings fund at Toyota, where is this wiring harness? I may try what Thomas said for one last shot.

Already have the bullet ready Lexus114

code58

This time Blue you know you only have to bite it- I thought Lex was getting a little drastic there. We can both breath a little easier. I agree with trying ANYTHING that might have a chance of detecting a problem that would avoid that kind of expense. I can virtually guarantee you that if it were only a wire connection problem that they're NOT gonna come out and tell you- "Blue this is your lucky day, it was only a poor connection. Have a nice day." Maybe in some other lifetime, but not this one.

I could tell a true story her about a problem very similar to this, but won't bore you. I can only say, it's not a bad idea when you're having a problem like that to unplug the plug, spray a little contact cleaner in both sides and "reset" the plug rapidly several times before firmly setting for the last time. I was re-reminded only today in another issue I faced, DON'T ASSUME THAT A CONNECTION IS GOOD JUST BECAUSE IT LOOKS CLEAN. Nothing could be farther from the truth! With todays electrical systems carrying so little amperage in the signal, a connection that looks virgin can still be the problem. (SEE ABOVE!)

blueridge

I just had the sensors changed yesterday with the T-belt. Noticeable improvement especially on acceleration.....Very smooth.

Lexus114 had it right when I first complained of pinging noises regardless of gas octane. "Could be your knock sensors going bad" he said, 6 months later P0330.

k.capone

So last week I replaced the A/F sensor pre-cat and took care of my p1150 & p1155 codes. This weekend when driving over the pass to Eastern Washington the VFC light came on right when I got to the 105 degree weather. Came home and pulled P0330 knock sensor 2 code. My car only has 52,000 miles on it. Could it possiably be a bad knock sensor, or bad gas. I have been using 87 shell. How do I check coolant temp. And what should it be. To start with I'm going to use premeium gas from now on. Any suggestions anyone?

Lexmex

As you suggested, switch to the premium gas first and then see if your condition improves. The coolant temp issue is only something I might check if you had a P0125 issue or come and go a/f sensor issues.

I'd try a Chevron or Sunoco if you have it there.

blueridge

Even after replacing my knock sensors, the engine ran better but not great until about 600 miles of using 93 octane with a combo of Marvel Mystery Oil and Seafoam.

Keep in mind, I my engine threw the P0330 code once, then worsened over the coarse of 3 months to about every week.

blueridge

Since writing this post I have dealt with slight engine knock on acceleration at around 3,000 RPM in second gear. I always use 93 octane but have played with different octanes/brands before. Some of the senior guys on hear may recall all of this, I did replace the knock sensors when the code kept popping but that really only silenced the code.

So, after resigning myself that this was acceptable since everything else is normal. I dropped it off at Toyota to have a state inspection preformed. While I was there I had them trouble shoot this. They were able to reproduce this but everything check out as normal, and they checked everything!

To my surprise they recommended an octane boost to see if it cleared up. So, after a full tank of 93 with octane boost/cleaner the knock is completely gone. What the heck? I don't want to keep doing this at every fill up plus it probably isn't good to use this product long term. What do you guys think?

Lexmex

See how it goes for a bit and if the problem returns it might be some gunk down in the fuel tank itself getting into the fuel mix (something I had an issue with in Mexico and still do to an extent here in Floirda, since I don't drive as much as I used to and my RX300 can sit for a bit).

I use this stuff, http://mystarbrite.com/startron//con...5/125/lang,en/ and can get it at West Marine (which you do have in North Carolina), http://mystarbrite.com/startron/content/view/122 It might feel funny for a bit, but this stuff does seem to do an excellent job of getting a lot of gunk out.

The gas treatment stuff, http://mystarbrite.com/startron//con...3/123/lang,en/ (as opposed to the fuel tank cleaner) is probably a good first start, but that fuel tank stuff will clean that gunk straight out.

blueridge

Thanks as always Lexmex.

I've run various treatments through the tank. Amsoil, Redline, etc and none made any noticeable improvements.

Is this an octane thing or is it the combination of the cleaner that works?

lexus114

probably carbon build up from running the low octane.

Carver

Maybe it needs a "German tune up". I used to sell Mercedes many years ago and little old ladies would come complaining of chugging, knocks, black smoke and dieseling so the mechanic would take it to the street behind the dealership, put it in low and redline it up and down the street. After he had blown out the cobwebs it would purr like a kitten again and off she would go to do some more one mile shopping trips.

blueridge

How the heck have you been, long time! Go Hokies!

I've been running mid to high grade for as long as I've had it (6 years) so maybe it was the previous owner. It's always done this and the knock sensor change (that you called) helped but only a little.

I'll be interested in how it runs after the tank with the boost is gone. Hopefully this is burning the carbon off and not the engine up!

lexus114

Hey I`m good! and I hope you are as well, (other than this problem in question) I didnt read it all again, but maybe it`s running too lean?