2012 v6 at DCSB engine knocking @ 1500 rpm

You will see no benefits running 89 or 91, those fuels are for high compression engines that specifically call for it like Audis, BMW and the Toyota FJ cruiser. Higher octane rating does not make it better fuel by any means it just makes combustion more controllable in engine that have high tolerances. The 4.0 would not fall under high tolerance/compression category. Run 87.

 

My 12' TRD OffRd was also made in Mexico/Baja. Noticed the sounds soon after purchase. Is anyone experiencing this issue with a Tacoma assembled at one of the other plants? Assembly plant location is listed on the decal located in the front driverside doorjam.

 

No, can't say as that's the problem we're talking about. That sounds...horrible.

 

FWIW, mine is also a Baja-built truck, build date of 3/12/12. I'd have put that in the survey (link above) if it would have let me put a few more questions.

I gathered up my documentation from the dealership and got the California Dispute Settlement papers filled out. Photocopying everything and then mailing it off tomorrow.

I basically said "Refund my money, because you have no fix and I can't resell this truck as-is". I could, but then I'd be making a material non-disclosure. That's a no-no.

I know they won't bite, and that's fine. This is to apply pressure. I'm going to punch Toyota in the cock.

 

Goodbye then.... Try higher grade gas

 

2006 FSM says the cylinder pressure during a compression test should be 189psi or "greater" on the 1GR-FE. I'm no powertrain engineer, but every other car I've owned that ran on 87 had a cylinder pressure rated in the 160's to 170's. By comparison, the 5VZ-FE specs out at 178, with a static CR of 9.6:1 (1GR is 10:1). 9.6 to 9.8 is generally considered to be the max CR you can push before you have to go above 87. The small block engine builders usually call out (as a guideline, not hard and fast) 200 psi = 93 and minus one octane point for ever decrease of 5 psi. So at 190 you're skating along with 91 octane.

Stack some tolerances the wrong way, get a little too aggressive with VVT-i adjustments, and I bet you can get the cylinder PSI well above 190.

Can you fudge it by dicking with dynamic CR? Sure. Did Toyota do it right? Guessing not.

 

Hey, I gave it a hard thought, too. Thing is, the Frontiers (MY 11 and newer) have reports of this same BS too.

 

Interesting, I was looking at it from a chemical stand point. There is a huge misconception with people believing higher octane content in fuel turns their car into a rocket ship when in reality more octane per volume actually decreases potential energy of the fuel.. on top of the fact that California has about a +/- 3 octane standard in their fuel measurement guidelines so even if you are buying 91 you may be getting 88 octane or up to 94. It is not as accurate as it seems.

 

Awesome right?

 

For what it's worth, Alcohol produces more energy than gasoline but needs a richer mixture than gas so fuel mileage suffers. That's why they don't add more than 10% unless a vehicle is designed for it.

I'm old school and don't know much about the new vehicles but in the old days 9 to one compression ran on regular, 10 to one compression used premium. A friend had a Honda hybrid that used regular with 11 to one compression. It's mind bogging to me, how highly tuned tuned vehicles are these days.

I did rebuild and blue print one engine a long time ago. Compression was about 11 to one. I rounded things such as the valve reliefs in the pistons and any sharp edges in the combustion chamber to reduce or eliminate any potential hot spots that can cause pre-ignition or pinging running on today's premium fuel.

One of my 1969 GTO's with a 10.5 compression pings like crazy on today's premium, timing is retarded a bunch. Plus I have to use octane booster or it continues to run after turning the ignition off. All original, pure stock engine with 93,000 miles. I would never consider going even half throttle with this engine running on today's premium fuel. It sure ran great in the old days on 100 octane, but the days of 100+ octane fuel at the pump are long gone.

Yet some of today's vehicles with 11 to 1 compression can use 87 octane fuel. It doesn't bother me putting premium fuel in my Tacoma. But I'm retired and don't put a ton of miles on my vehicles. Although it would sure be nice if I could get some 100+ octane at the pump once in awhile. My pure stock GTO barely runs on the crap that comes out of the pump these days.

 

Dude. Don't know where you are in the Bay Area, but 100 Octane Sunoco @ the pump. 76 Station on Woodside Road, between El Camino and Alameda, Redwood City.

Google around a bit, too. There are other stations in the Bay Area selling 100 octane race gas, still. You're gonna pay $8 per gallon, though. But you retired people are all rich, right?

 

I grabbed the 2012 Dept of Consumer Affairs (state agency) petroleum station testing report. They pulled samples from like 300 stations (gasoline and diesel). There was 99%+ compliance between octane label and octane rating.

Ethanol could have something to do with it, too. It increases octane, until it phase separates (water contamination). If your tank is full of separated or semi-separarated gasoline + ethanol/water, effective octane drops to whatever just the gasoline would be.

Toyota can't fight that one. Word from some EPA folks I know in D.C. is that automakers are basically losing (lost, really) the incoming E15-E20 mandate. The 2014 Toyotas (some, at least) are already rated to handle up to E20. The EPA is bending us the hell over.

 

If it makes you feel better California has crappy gas I mean I use regular all the time and don't have an issue so it has to be the Gas or a bad knock sensor.

 

You do know that until the 07's toyota's owners manual DID say for best results use 93 octane. So yeah, the 4.0 can see benefits using higher octane premium fuel. Oh yeah, for the other poster who asked about where your truck is made, mine is a mexican and no ping here. Guess I got lucky?

 

Gone traded it in. Good luck everybody.

 

Those with non pinging engines do not complain only the few that ping do.

 

If it was "a few", Toyota wouldn't be looking for a fix. The Service Advisor that wrote me up on Monday ran a search of the Repair Order system. 71 complaints of this issue in the past 36 months, 29 of those in the past 12.

That's *one* dealership. Most owners aren't going to get on a forum like this to vent about the issue.

 

Update: month three using 93 octane and haven't heard or had any issues. Not mechanically savvy enough to say I will no longer have an issue or prevent future damage, but my truck does seem to be running much smoother. That being said, I am also considering trading my truck in for something else. I spoke with a Toyota manufacturer rep and he gave me absolutely no hope of a fix. It's obvious they know the issue exists and I'm sure he was reading from a pre scripted response. My friend/neighbor has an 05 and his knocks as well. He's too cheap to run premium and has 85k on his truck. I doubt this issue will cause any major malfunction but I'm not a mechanic. Anyone with this issue with high mileage that can give us hope?

 

that was my main concern. Is this pinging doing damage and will the motor hold up over time. I was not willing to wait and see what Toyota was going to do if anything. I traded mine in for a frontier yesterday. It is definitely a give and take . Not as comfortable as the taco and a little cheaper feel on the interior. Outside I think it is comparable in looks and quality. The engine is way more responsive in the Nissan. Never would have dumped the Toyota if it was not for the motor.

 

You know the rules of the internet....Pics or it didn't happen.

All joking aside, I'd like to see the truck and hear you elaborate on your thoughts about it.