MAJOR PROBLEMS 2012 V6 4.0L

Howdy,

First post here and have always enjoyed reading this forum since before I even bought my Taco. Sadly my first thread has to be about a major mechanical issue of unknown origin so I'm hoping y'all can help me figure it out, as of this time the dealership has basically no clue.

Driving with the family today and I started noticing a loss of power and what felt like the engine missing, it went away and I chalked it up to road conditions as my tires are stock and wearing out. A few minutes later BAM it hit like a tire blowout, truck starts shaking and Check Engine light is flashing and Trac OFF light comes on. Every time I accelerate it gets worse. A Toyota dealership I never used it not far away so I pull in.
After a couple hours they tell me they think it is bad gasoline as "it has unknown miss firing happening in all the cylinders" and they can't find anything else wrong with it. Now I did fill up yesterday but I've driven at least a quarter of a tank since then and I added octane booster cause it's cheaper than buying premium at $2 a bottle. They told me they could drain it or I could just drive all the bad gas out of it. I asked them if that was okay and they said "sure it won't hurt the truck" At this point I was pretty ticked off. I've always been told don't drive a vehicle for long with a misfire cause it screw stuff up in the long run if not immediately. Waiting on their call tomorrow.

Note: I've been feeling something odd for the last few weeks but I couldn't put my finger on it, nothing big just enough to give me pause and say "what was that?" It could have been an indicator that I missed.

Any thoughts on the subject? Thanks in advance, I always love the great content and posts, hoping to get some of that here.

2012 V6 4.0L 4x4 double cab 42,000 miles.

 

my 0.02

I'm no expert but if you have burned 3/4 tank of "bad gas" I would fill up with a "top brand" Premium to dilute what you have and hopefully things clear up. Then continue to run "top brand" Premium and see if things run normally for a few tanks.

It sounds like your truck tried or did enter "limp home mode". This could be because of the misfires. Always get a list of Trouble codes so you can do your own research. Did they at least clear the codes? Is it running normal now?

Personally I use Regular daily and don't have issues with my 2006. I am getting better mileage running Mid-grade and I am sure my truck appreciates it.

 

DO NOT USE OCTANE BOOSTER! I've never heard good things about it. Motors are like people they become addicted to octane booster and can't run right without it. Had a friend who always ran octane booster (don't remember what brand comes in orange bottle from auto zone) in a camaro. Ran that stuff for 30,000 miles and no more motor went to rebuild it and the inside was so gummed up with what llooked like orange moss from the octance booster. Try finding a gas station with 100% no ethanol gas and run a tank of that and run a bottle of fuel system cleaner through it. Usually shell has no ethanol or at least every shell here does.

 

They put the good things about it right on the bottle The non-ethanol couldn't hurt, as well as running fuel cleaner (not necessarily together).

I'm surprised you don't think those are snake oil.

Serious note: Cars cannot get addicted to anything...addiction is physical and mental. I assume your friend drove the car like a camaro, racing it, adding camaro-y things like K&N, cold air intake, retarding the timing, smoking the rings, and burning oil and other crap in the gas to the cylinder walls. Especially if he had to rebuild the motor after 30,000 miles.
Not serious note:
You are crazy dude, I am not, cannot, and won't get addicted to Octane Booster. I hear, from a friend, that it tastes awful. So what if the cool kids are drinking it, I definitely don't do it. Pass me the Octane Booster, lemon please!

 

Why do you think you need octane booster in a truck that runs fine on 87? I ran one tank of 93 in mine without any discernable diff in power or MPGs.

 

I see you are from Houston. Could this be the problem?
http://fuelfix.com/blog/2014/07/10/chevron-investigates-bad-gasoline-in-houston-pumps/

 

The reason I put Octane booster was at the direction of a Toyota Tech previously. I have a noise that sounds like knocking cylinders and he prescribed either supreme fuel or octane booster as a remedy. It has helped but not completely. The Tech has previously told me that it a problem with the engine but it's basically cosmetic. Toyota is working to figure out a fix for it and if they do they will issue a recall.

They still have the truck, I'm waiting on a call.

I used a fuel system flush in an older vehicle and it seriously downgraded my mpg by like 4 miles per gallon. Cautious on using any in such a new engine, but at this point I'm willing to try anything.

 

I recommend to all of my customers to never use an octane booster. It can cause long-term damage to an engine. Not something you would notice immediately, but over 30k miles you can tear an engine down and see lots of problems from those products. Especially in the intake manifold. Remember that the only difference between regular unleaded and supreme is the octane percentage. Higher octane fuels are simple more resistant to preignition, thus they are recommended to be used in engines that have a high compression ratio, or those that are supercharged or turbocharged.

There have been scientific tests after scientific tests that show using mid to high octane fuel does NOTHING to improve your engine operation if your vehicle is rated for only 87 Octane. Those that claim better MPG are just being fooled. Simply having different quality of fuel, different acceleration rates, more stop and go over a longer drive period, can all affect fuel economy. I use the same fuel all the time from the same two stations, and my fuel economy is never consistent, because the way I drive is never consistent. I have had tanks that got me 21 MPG, and tanks that got me 19 MPG. Basic changes in air temperature and humidity can even affect fuel economy. For example cooler days with dry air will get you better economy than humid and hot days.

Back on point though, it is not a good idea to use octane boosters. I do however recommend to my customers that each time after an oil change, when they fill up the fuel tank, to add a small 6 oz bottle of STP fuel injector cleaner. With the ethanol in gasoline so common, adding a bottle of the STP cleaner will help remove the varnish and build up that has been known to happen with ethanol fuels. The reason you most likely ran into a problem with flushing the older vehicle JF86, is because there was probably a significant amount of varnish and build up on the fuel injectors or carb that the cleaner was probably breaking up larger pieces, which would cause a problem until it was all cleaned out. My 97 Tacoma with the 2.7L engine when I first got it was lucky to get 18 MPG. When I started running STP in the tank I lost 2 or 3 MPG for the next 4 or 5 tanks, then the MPG went up to 22 and stayed in that area. (At least until I got the bigger tires and lift! lol)

 

Bill,
Do you mean this stuff?
http://www.stp.com/products/fuel-additives/super-concentrated-fuel-injector-cleaner/

 

Does it do this when idling, running steady or during acceleration?

 

I was prescribed the octane booster not too long ago, maybe 8,000 miles. Thanks Bama for your info.

It appears on acceleration. Not idling.

 

That is the stuff! I put a small bottle in my tank at the first fill up after I change my oil. So around every 4k miles. (I use synthetic oil)

No worries. I help with what I can.

 

I had a vehicle that did this somewhat. It ran OK around the side streets but as soon as I hit the on ramp on the interstate - it would sputter, shudder and die out. Once up to speed it was OK. The car was fairly new and the shop had a difficult time trying to narrow it down. It was the fuel pump. Low volume/pressure when needed (acceleration). (it passed a pressure test in the shop...)

I'd also check any in line filters (tank, line, injectors).

I also know of some clown who threw a baggie in the Tank (possibly a druggie hiding a stash from some cop at a parking lot?, or some such ...). The baggie would slosh around but usually at a left turn, uphill at 1/4 tank it would get sucked around the pump inlet in the tank. once it stalled/died and the engine stopped or went to idle, the baggie floated off and the engine ran fine..... It drove the owner nuts until they pulled the fuel pump for the second time and happened to fish out the baggie.

Just some guesses for you ....

 

Haha barring my truck being used as a drug mule the rest of that was pretty solid advice. Haha. Thanks for the input Canufixit!

 

Update:
Dealership called said it was bad fuel that ruined the spark plugs. They want to drain the gas and replace spark plugs and said it was going to cost $1100.
Ouch. Thinking of doing it myself, spark plugs are easy, draining the fuel is a different story.

 

So u got a load of bad gas... How is this "OMG MAJOR PROBLEMS W 2012 V6!!!" ?
Seriously, pour a drink n relax.

 

The owners manual for V6 Tacoma's states:

87 Octane recommended - Research Octane 91 and higher.

That means don't run anything higher than 89 in your truck. Higher octane does not mean better.

Question though - What brand of gas was the culprit???

 

He didn't know it was bad gas when he started the thread there cool-mo-dee.

Seriously, stop drinking and relaxing and start thinking. . .

 

Syphon out old gas, and buy new plugs. $1100 is ridiculous!

 

wut