2012 v6 at DCSB engine knocking @ 1500 rpm

See, I can still get knock when I put the shifter in 4 (even in 3 on a really steep incline). It's not as severe, but it's persistent and it won't stop until I stop the truck fully, let the trans shift down into 1st, and then start out again.

If you're correct, then it's a simple reflash of the ECU to change both engine control and transmission control.

Turns out some new D-MAX trucks overseas are using the same gearbox as us, but under the AisinAW numbering - TB-50L I think it is. No complaints from those guys, but they have different mills and programming under the hood.

 

Chrisman.....I thought about that but there are trucks out there with really big tires, same trans and 4.0 V6 that tow much heavier boats and trailers that don't have the "Knock".....

Hey.....what temp thermostat are we using in our trucks? I thought most newer cars and trucks ran at 180 degrees??

My knock is most prevalent when my ultra gauge reads 190.3...

Sometimes it runs at 186 and seems to run with more low end power....

Is it a possibility we are losing torque when the motor gets too hot?

 

My engine coolant temp depends on ambient air temp, vehicle speed, highway vs. street, and probably some other things I'm forgetting. Stant claims the OE thermostat is a 180F unit. That's interesting, since the 5VZFE was 190. Usually they run engines hotter for emissions purposes at cold start and use EGR to counteract NOx due to combustion chamber heat.

On a 55-60mph cruise, I see about 184. Closer to 70 and I see 184-186. Only going uphill, on street or on a very long uphill section of highway at lower (50mph), do I see temps in the 188-190 range. I think I've hit 191 once. Other things that will impact this are whether you have the towing package (aux. cooler for AT) and the oil cooler (dumps more heat into the coolant stream).

The Toyota stock thermostat should be fully opened at about 176F. My truck will knock at 184 and it will knock at 190. I'm not sure it's more prevalent at any particular temperature. Where it seems to not happen as much is when ambient air temps are in the 50's. In the 70's, and I'm guaranteed to have it knock. In the mid-50's, it won't always do it. And I can have identical coolant temp readings at either outside air temperature. The difference there is intake air temp.

 

Came across something interesting. 2005 Tacoma parts lists have one part # for the knock sensors on the 1GR-FE. I skipped up a few years to 2011 and found that there are two part numbers, the original and a newer one:

89615‑20090 (old) or 89615‑06010 (new). Seems many Toyota engines use one of these part #'s. I wonder what the change was (or if it was just a p/n change only).

http://www.toyotapartszone.com/Page_Product/PartsFits.aspx?partNumber=89615-20090

Looks like the Tacoma stopped using the old p/n in 8/2010 for the V6 (if 2010.08 means 8/2010). I wonder if there is a QC issue with knock sensors. It's logically the simplest thing to check, but monetarily one of the more expensive. You can't get at the damn things without taking apart most of the top end.

Getting tired of chasing this demon. Probably what Toyota's hoping for, too - give up and bite the pillow.

 

Hey obscurotron.....

Are you a mechanical engineer?

You are hardcore buddy....

Not sure if I want you to represent me in court when I tell them I want a refund or have you work at the dealer that fixes my problem.......lol

 

No, I left the ME track in college when the math just got way over my head. The first year of calculus wasn't bad, but the 2nd year left me scratching my head.

Really, it's just about using whatever resources you can find to research a problem. But everything is a dead-end. Example: no way to really tell what (if anything) is different between the two knock sensor part numbers. It could reflect a design change, a supplier change or it could just be that Toyota got a wild hair and decided to change the part # scheme because the SAP and Oracle guys needed something to do. I just dunno.

 

I finally had a chance to do some testing under load this morning.

Transmission in 5th, TC locked, vehicle speed ~30mph, engine speed ~1100 rpm, warmed up, closed loop, slow traffic, ECT 181F.

Cruising @ 30MPH turning 1100PM:

IGN: 25BTDC
STFT B1: 0
STFT B2: 0

Roll on throttle from the scenario above:

IGN: Starts at 25BTDC, during transition retards to 13BTDC
STFT B1: -2, then -4
STFS B2: -1, then -3, then -5

Can anyone explain to me why, in a high gear/low speed situation, the computer would retard timing when the throttle is open *AND* start cutting fuel? I'm not an engine management expert, but that doesn't make sense to me. In the situation above, I read it as creating the perfect situation for pre-ignition. A leaner mixture with the spark further back in the compression stroke would mean the mixture will likely ignite before the spark plug fires, and that mixture will burn quickly, and finish burning, well before the piston reaches TDC or a point ATDC. Piston coming up, pressure front expanding against the piston - that sounds bad, to me.

The above is one set of data. I ran the test 5 times and got similar results each time. I also noticed that taking my foot off the gas in the middle of the test (tried this 2 times) would cause the B2 STFT to hit -11 in one case, -9 in another. B1 STFT went up, but not as much (-6 and -7). I could see STFT dropping like that snapping the throttle closed from WOT.

Assuming there's another piece of the puzzle here that I'm missing. Hoping someone that knows more about fuel and spark management can educate me.

 

Well......Since I'm waiting for corporate to "Get back to me" regarding my issue I went ahead and put my wheels back on and filled up with "Super Unleaded"

This sucks......

I normally tow my little boat to go fishing 3 or 4 times a week, because of the knock by boat is sitting and so am I.......

Is there anything I can call corporate and ask for to make me feel better?

I don't have the $ or resources to demand a new truck or a used one that isn't pinging

 

You can call them and ask for the moon. Odds are, they won't even give you a reach-around.

Don't feel too bad, I'm in the same boat. The pinging is getting worse. When it started in May, it was terrible with 87, and 91 made it less so. Whatever is going on (computer adaptation, exacerbation of the underlying issue, etc.) has caused the pinging to reach the severity I noticed originally with 87, but while running on 91, and it stays longer, too. Used to start about 1500rpm and cease about 2000rpm. Now I notice it hanging around until 2200-2500RPM.

 

Arbitration hearing is over. Arbitrator wants an independent mechanic to test drive the truck. Despite the dealer saying they noted the problems. I'm not sure what that test drive will prove or show, really. Sounds like misdirection, to me.

Beyond that, Maurice Howard from Toyota corporate was the only Toyota representative there. I directly asked if Toyota was in fact aware of this and whether a fix was coming. I also asked how many engines they tore down to inspect, if any and whether they determined the root cause.

1. Toyota is, in fact, aware. Dealer statements to the effect are not B.S.
2. Unknown if there will be a fix. No info on how long Toyota has known or
how long it will take for a fix (if any).
3. No info on how many engines torn down to inspect, if any.
4. Unknown if there is any ongoing damage concern. Opinion: No damage. That's
just an opinion and it doesn't mean shit IMO.
5. No info on root cause, obviously.
6. Mr. Howard said those with the ping should be running 87 octane fuel, because
that's what the manual calls for and this is the opinion of Toyota FTS. Never
mind 87 exacerbates the problem. Let's all screw up our engines more, based on
Toyota's advice.

These are the results I expected, more or less, so I'm not surprised. I'm debating whether or not I want to now go the lemon law route with this thing. I'll figure that out after I think about it. In the meantime, I've lined up a Frontier Pro4X to test drive on Saturday. From what I read on Frontier-based forums, it's going to be no better, but no worse, than a Toyota Tacoma. But I'm curious enough to see how the things drive and whether it would fit the bill for what I need.

After 26 years of Toyota trucks, I'll be sad if I leave the family. Stupid to involve emotion in a mechanical thing, but such is the case. I expected (not unreasonably) better from Toyota products. My '92 pickup was beat on and it did 180k before the timing chain went. My '97 Tacoma went 140k before the HG (2.7) went. I opted to not fix it. I could have and I bet it'd still be here. My '02 Tacoma was a good truck, only traded away to get an '04 with an auto (commuting at that point in time made it better choice). And the '04 only went away because the family added a member and I needed a 'real' back seat.

That doesn't include all the use I put on pop's '84 truck (went 270k before too much of the body rusted away) or grandad's '85 (167k on the clock and it's still running!!). Or the nearly 300k on dad's current 98 4Runner (love driving that thing).

Time to decide if I'm gonna shit or wind my watch.

 

Wow.....not the news I wanted to hear...

I should have emailed you the service records and dealer comments on my truck to see if that would add more firepower...

Can we get more people together that are in the same boat, split the cost and get an attorney to represent us as a group?

I can't afford another car, still have $13g"s to pay off on my truck and this is my daily driver that transports my 2yo daughter....

 

I talked to the parts mgr at Arlington toy the other day. He said thst Toyota dose have a fix for the problem but they will not release it to the dealers until the 2sd week of December. His truck has the problem as well.

 

You all know that Toyota make 2 different V6. We have the old style in the Tacoma but the FJ & 4runner have the newer engine also tge newer one makes 270 HP.

 

You're talking about a class action. Unless you gather up several thousand plaintiffs, that's not going to happen.

Gathering $$ isn't important. Most of these cases go on contingency or statutory awards of attorney fees. I won't get into the gross details, but most of the time coming up with money is not a concern in lemon law and class action suits.

I had plenty of ammo as it was. It's just that the arbitrator didn't really care.

 

Yeah. Up until some point, the FJ and the 4R had the same motor as the Tacoma (V6). I think 2010 was the cutover for the FJ, don't know about the 4R.

 

I think you were fed a line of BS. If a representative from the regional office, who had 3 weeks to prepare and understand the reason for the arbitration, couldn't tell me that, I strongly doubt a parts manager is going to know any better or have more information.

 

In the 2012 Toyota Tacoma Owner's Manual, in Section 6.1, on page 569 it states:

■If your engine knocks
●Consult your Toyota dealer.
●You may occasionally notice light knocking for a short time while
accelerating or driving uphill. This is normal and there is no need for concern.

 

My 2011 manual doesn't even have that many pages. I checked couldn't find any knocking advice. What's the title of the section?

 

Just kidding found the same thing on page 504. In my manual. But this is still bs in my book.

 

The thing is that it's not occasional light knocking. Under the right conditions it knocks consistantly every time without fail. Its probably even more pronounced down here in South Florida where it is still reaches the 90's during the day.