There is a loud cracking/rattling engine sound after replacing knock sensor #2. I double checked all hoses and wires and everything seems okay, switched it on again to try and hear where it's coming from for like 5 seconds but really that sound is loud and scary; after looking here and there and checking everything again I tried to turn it on but it won't start, felt like the battery died all of a sudden, charged it, turned on fine with that sound then just gave up. I also changed the sensors wiring harness, bypass hose, intake/plenum gaskets, spark plugs, air filter and PCV.

I am not getting the knock sensor code anymore or any other codes at all, I scanned multiple times but nothing. One thing to mention, while refilling the coolant I drained I heard a leak somewhere and noticed that I missed a hose somewhere under the maf sensor but other than that no leaks, smell or smoke of any kind.

All parts are OEM from Toyota

Please help and thank you.

 

I am in favor of replacing the PCV valve again and checking the hose from it for oil and sludge buildup. You said you replaced it, but I have seen defective ones out of the box. Also, did you use Teflon tape on the new one? You should when installing.

BTW, I had no lights/codes when I replaced mine just recently for a lark... and noticed easier starting and better response annnd... that sloppy automatic transmission shifting problem my series (‘05 ES) has all but disappeared.

 

Hey could you elaborate on the "sloppy automatic transmission shifting problem my series (‘05 ES) has all"

 

It’s like the transmission doesn’t know what gear to use (lower ones) in stop and go driving or when making turns. Most everyone that has the tranny series my ‘05 has knows what I mean. There are a dozen threads here on clublexus to it’s credit and if my memory serves me correct, there was even talk of a lawsuit about it. The ECU and the tranny “software”(?) don’t work well together when downshifting and speeding back up causing some really bad shifts at times.

Anyways, the reason I say PCV is because the symptoms of a bad one are described by Mobsky and it’s the easiest and cheapest item he listed that he changed. My old one rattled and passed the suck/blow test, but the new one made mine start instantly and response was better.


My “cure” through experimentation is to “pet” your car with hi-test, keep your MAF clean, keep the air filter clean and I keep tire pressure right around 35lb front and rear. Works for me.

 

If you are talking about hard downshifts I also experience that. What did you do to resolve it? Just change the knock sensor?

 

No, I’m saying rather than pulling the top half of my motor off again to scratch your head about a knock sensor, just change the PCV valve out again because the few symptoms here remind me of a bad one. And besides, it’s a cheaper and easier first step.

I don’t know what year your Lexus is, but I know the ‘02 thru ‘06 ES models had the hesitation/confusion factor I’m speaking of.

I said previously that I baby mine and I guess my OCD is paying off.