I have a 2001 ES300 that has been making a clatter/pinging noise for the past 2 months or so. It currently has 185k miles. And here is a list of what’s been done recently to it:
-6 Denso Iridium Plugs - 173k
-Seafoam - 174k
-Oil changes every 5k with Mobil1 Full Synthetic
-Replaced A/F sensor near the radiator with Genuine Denso - 176k
-Cleaned throttle bodies and MAF - 178k
-Replaced both valve cover gaskets - 178k
-Replaced bank 1 vvt solenoid - 182k
I have been running 91/92/93 octane fuel in it regularly for the majority of the time since I bought it new. I have tried running 87 and 89 in it and it hasn’t changed the noise at all. After reading around I’ve heard that running premium can sometimes create excess carbon buildup in the engine over time. Here are a few things I’ve done/considered doing to try and fix this issue:
-Done multiple ECU resets by pulling battery cables and/or fuses = no change
-Throttle bodies and MAF are still clean
-As far as I know there are no vacuum leaks, no intake hoses have cracks in them
-I’ve thought about maybe running seafoam through it again, it did produce quite a bit of smoke when I did it back in October
-In the winter I ran Mobil1 0w-30 full synthetic oil and that’s what’s currently in it now, maybe this is too thin for the summer heat?
-The sound is mostly under harder acceleration but can be heard all the time as well regardless of incline
-With 87 octane the car seems to run really sluggish and every once in a while would knock loudly for 2-3 seconds so I switched back to premium
-Not sure when or if the timing belt has been changed, I know it’s risky and I’ll get around to replacing it, the water pump, and seals within the next month or two - maybe this noise could be timing belt related? - Belt didn’t look that bad when I pulled the timing cover off.
-No clue if any of the knock sensors have ever been touched by the previous owner
-Possible valve adjustment needed?

I have no CELs and haven’t ever had any since I’ve owned this car with the exception of the A/F sensor one. I’m not really sure what to try first to solve this problem, or if it’s even that big of a problem at all. I’ve thought about using fuel cleaners with PEA and seafoam but I’m not sure if this would help or not.

Here is a video of the symptoms, not sure if you can hear it on camera that well or not, it’s a ticking/pinging sound when accelerating -
I appreciate everyone’s help,
Zach

I have had great success with additives using PEA. Techron has it. I use Gumout Regane HM, it is $5 from Walmart or Amazon. Try two treatments in a row, then one every 5k or whatever it seems to need.

Your oil (the base oil before additives are blended in) is indeed thinner than you honestly need in KY, and has additives to get it up to the hot 30 weight spec you don’t need or want. I would (and do) run the Mobil 1 high mi. 10w-30 year round. I am from around Louisville and know the climate.

Thanks for the suggestion, I went ahead and drained and filled with M1 10w-30. I bought a bottle of the Gumout Regane HM and I’ll add it in once my tank is near empty.

I never thought to check for exhaust leaks, I just thought it seemed quiet enough to not have any but I definitely will check. I will drive around for a while and get the long term values tomorrow. Here is what I picked up for short term fuel trims at idle and 2500rpm:
Idle:
Bank 1 - 0.0%
Bank 2 - 0.8%
2500rpm:
Bank 1 - 0.8%
Bank 2 - 0.0%

Thanks,
Zach

Here’s a graph of my fuel trims during a 50 mile highway trip, average speed 65mph.

I ran half a bottle of Seafoam through the brake booster line and let it take its course. Not much came out but it did help me confirm that there are no exhaust leaks whatsoever. At first I thought the noise sounded like valve clearance being out of spec but from what I’ve heard the valves usually don’t go too far out of spec on 1MZs and they’re a pain to adjust.
This sound still sounds like spark knock to me and it only occurs when accelerating. It does not do it when you rev the car in park. I’ll have to check for vacuum leaks and see if I can find anything. I’ll add the bottle of gumout to the tank in the next day or two when it’s time for a fill up. I wish there was an easy way to test the knock sensors because I’ve been wondering about those recently because I’m unsure if they’ve ever been replaced. I have no CELs still but I’d rather not spend $350 on two new knock sensors if I don’t have to. Or could it be the other VVT solenoid going bad? I only replaced one side’s. The screens for both solenoids were clean when I replaced the one.

I also have a 2001 Krxus Es 300 that pings slightly under load. But only during high ambient temperatures. The Lexus owners manual states that pinging under certain conditions is perfectly normal, and that basically not to worry about it.

i doubt your timing belt is slipping, but if it’s past due than change it. When I changed my timing belt at the specified interval the pinging remained the same.

si as I said, it could be normal.