2016 OVTune Tacoma 3.5L Manual Transmission / Engine ECU Reflash

well... Now I need new tires before the tune =(

 

there's a lot of YES PLEASE in that vid...

 

Alright fellow TWers...I may have found a problem with the glorious 1.04A 91 at the edge of an edge case. @OVTune please also chime in.

Over the weekend, I was towing a single open car hauler, with a VW Golf TDI on the back over about a 600 mile round-trip. I estimate the total additional weight about 5500lbs, plus an extra passenger, luggage, etc. It was great having the extra power! However, I noticed something strange on multiple occasions.

Towing all of this extra weight of course required use of lower gears at higher engine speeds, usually still at full load/full throttle command. On the steepest grades (about 4-5%), I would notice some pretty serious knocking/pinging around 4000-4500 RPM WHILE UNDER FULL LOAD (usually 3rd gear in these cases). The truck was giving everything it had to give, pedal on the floor. I run only name-brand 93 octane fuel. I noticed this over 2 full tanks of fuel from different stations.

I'm not sure what could even be wrong to cause this issue, other than the symptom is knocking. I'm thinking it has something to do with the modified timing.

Other than this, I have LOVED 1.04A, the extra power is perfect, and according to Fuelly I have gained an average of 1.2 MPG without changing a thing! I've had no other issues either.

 

Interesting. Who was it that did a bunch of towing also recenrly? Don't recall if they ever reported this, but curious what Matt has to say

 

As a subaru owner, pinging under full load at 4krpm sounds like a death sentence. It would take one, maybe two hard pulls like that to blow a boxer engine, obviously we have more leeway being NA, but damn.

Did you see the rpm jumping with the pinging? Im sure Matt would love to hear about this privately instead of it being put on the forum, but I'm glad to have heard about the issue.

 

As soon as I got the first pinging I backed off immediately. No RPM jumps, and all of my temps remained normal. The truck never once went over dead center on the coolant temp.

I have had hit-or-miss luck contacting Matt privately and this is an issue that others should hear about since it is really not good if you experience it. Not here to flame, I still am really impressed with 1.04A, but I am here to see if others have experienced it and put it out there that it could be an issue. Besides, full load high RPM towing the max GCWR at highway speeds is an edge of an edge case. Not something many will experience, and not something anyone here is doing regularly enough for it to be disastrous.

 

been waiting to see that post for over a year. good stuff.

 

Thanks for sharing the info!
I could be a good test bed for a solution due to the load I carry

 

For sure and I didn't mean to act like you should keep it quiet, I just know he prefers to find out problems or quirks before it is publicly spread. The knock control systems, like all the safety systems, are still in place as I understand it, so im sure it pulled timing and probably added fuel to compensate and keep damage from occurring.

But if you can hear a ping, or especially several, it's a big deal, especially at high rpm/load. Basically a sledgehammer smashing the piston down as it rises...

 

Guys.....Autos don't have nearly the flywheel as a manual. They have a light flex plate hooked to a torque converter. Not as much inertia. Makes rev up and down faster.

 

I had pinging with 1.03c in my truck. Figured out that my usual fuel station had some really crappy fuel. Switched brands and have had no issues. I also started using Lucas upper cylinder lubricant 4oz per fill up after that.

 

Is your truck affected by the sensor recall?

 

Although there's still some inconsistency WRT throttle response when rev matching, the tune allows me to drive my truck pretty much like any other M/T I've owned. No more mental gymnastics, it's just natural again.

Your story sounds like mine lol, clunk clunk clunk on the stock calibration.

 

Had pinging under heavy load on 1.03B/C 91 and 1.04A 91. Backed off, then continued driving normally.

Asked Mat about it, his answer was the truck can also do it stock and that it's normal until the knock correction and such settles in (the ECU has to find the limits).

My truck did it for quite a while, then stopped completely (I don't remember exactly how many miles, but in the hundreds).

I don't think anyone is in danger of the damn thing blowing up lol. It was pinging, not detonation.

 

They are the same thing

 

Fixed my previous post.

While I understand your concern, someone might come on here and see the comments about boxers blowing up under "similar" conditions and freak out unnecessarily.

I am not downplaying your posts or saying you're full of shit.. it isn't an apples to apples comparison though.

@OVTune.. I know you've answered this before, but can you comment on knock experienced under high load with the tune (post #6210)?

 

Well great, then Toyota has made the only engine that is fine with pinging under high load.

I think I made it clear i was talking about the turbo'd, port injected, EJ series engines that were new almost 15 years ago and not an almost brand new naturally aspirated direct injected engine in our trucks, but that is neither here nor there.

If the knock was present under the stock tune, fine, it shouldn't be now. And if it really takes several hard pulls full of pings for the ecu to permanently pull timing/add fuel in that area, fine also, but it isn't something I would expect. Nor is it something that is just a meh, don't worry about it.

If you hear pinging, you are hearing the effect of some several hundred psi acting explosively directly against a rising piston. It wears EVERYTHING prematurely and can cause failure quickly. This is why I even mentioned letting Matt know first, cause this sounds like a big deal to me. I'm certainly not trying to scare anyone off the tune, I don't have it but plan on buying it when it is next available. I love what he is doing with this truck. Like others, I'm not looking for more power, just to be able to drive a smooth and predictable MT truck.

 

For posterity so we get our terms right...

Edit - this same page I posted does list the effect of ping/knock to range from inconsequential to severe, so I stand corrected on that. But I would assume that takes into account how often it occurs and at what RPM and load etc. I'm a marine engine guy foremost with some limited tuning experience on subarus, so I know there are areas that my knowledge is lacking.

 

Perhaps the 91 file has TOO aggressive timing.....mayne bring it down slightly to allow for more wiggle room???

 

Anybody be able to test and replicate this behavior on the 87 file?