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Perhaps the wider pipe has more turbulent air at low RPMs, but flows better at higher RPM?
 
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Discussion Starter #82
Perhaps the wider pipe has more turbulent air at low RPMs, but flows better at higher RPM?
Potentially but I did not change the intake itself I have had the AFE on this entire time, I just wrapped it where it was making contact and cleaned the filters is all.
 

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I’ve found there are a lot of factors that play in the part throttle KR. Like weather, fuel, oil, tc.

Fuel has been a big one from my observations. Running 91 I get the occasional part throttle knock when leaving a stop. Ranges from 0.5-1.5. BUT the longer I idled, the higher the KR. For example idling at a stop for about 2 minutes. I’d instantly get a jump to 6 KR when only part throttle.

Yet when I ran an e-30 blend, not once did I get KR. Even idling for a couple minutes at a stop. Nothing.

I feel like it’s just a mixture of hot charge temp from idling, fuel, and aggressive spark causing the part throttle KR.
 

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Isn't this issue what the newer SN PLUS oils are made for ?
 

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Discussion Starter #85
I’ve found there are a lot of factors that play in the part throttle KR. Like weather, fuel, oil, tc.

Fuel has been a big one from my observations. Running 91 I get the occasional part throttle knock when leaving a stop. Ranges from 0.5-1.5. BUT the longer I idled, the higher the KR. For example idling at a stop for about 2 minutes. I’d instantly get a jump to 6 KR when only part throttle.

Yet when I ran an e-30 blend, not once did I get KR. Even idling for a couple minutes at a stop. Nothing.

I feel like it’s just a mixture of hot charge temp from idling, fuel, and aggressive spark causing the part throttle KR.
Yeah nothing out of the ordinary today that would have caused a change, I mentioned the only changes made from yesterday to today, trying to get an understanding how I may have made an improvement by just those two small things.

As for fuel, no fuel has made any change for me in the partial throttle knock, I can run 87-94 from any station with octane booster or not, ethanol or no ethanol and it reacts the exact same way every time.

Also in my instance it does not change if I have sat for 5 minutes or 5 seconds the truck will do it randomly when taking off from a stop with no consistency in why.
 

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Discussion Starter #86
Isn't this issue what the newer SN PLUS oils are made for ?
Im not sure but I have tried the different suggestions of Mobil1 and Castrol for direct injection engines and regardless of brand I use it doesnt change the knock issue either, also as this is super inconsistent it doesnt make much sense to me to be fuel or oil.. Like I have said the changes I made yesterday seemed to have a positive effect
 
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So in your case its definitely sounding like false KR. Forgive me if someone has mentioned this before hand, have you checked the heat shields? Also I’ve had in the past where a bad tensioner pulley caused KR at low rpm and high rpm.
 

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Discussion Starter #88
So in your case its definitely sounding like false KR. Forgive me if someone has mentioned this before hand, have you checked the heat shields? Also I’ve had in the past where a bad tensioner pulley caused KR at low rpm and high rpm.
Yep, I have checked all of the heat shields the exhaust seems to be clear of everything. That's interesting though, Tensioner on the serpentine or the chains?
 

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Serpentine. It’s a very easy change. I did it anyways on 2011 as it hit 160,000. It was still in very good shape but I could tell it had some resistance/squeak.
Also there are 2 hard lines that run from the bottom of the radiator at the front the engine. They run together in parallel into a metal bracket. You can actually physically move them and they will rattle. Those in the past I had to foam around or zip tie them together. I’ll try to provide pictures when I get the chance. You can see them directly from the top of the engine bay looking down behind the radiator.
 

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Discussion Starter #90
Serpentine. It’s a very easy change. I did it anyways on 2011 as it hit 160,000. It was still in very good shape but I could tell it had some resistance/squeak.
Also there are 2 hard lines that run from the bottom of the radiator at the front the engine. They run together in parallel into a metal bracket. You can actually physically move them and they will rattle. Those in the past I had to foam around or zip tie them together. I’ll try to provide pictures when I get the chance. You can see them directly from the top of the engine bay looking down behind the radiator.
Thanks I will give those a check!

Also some more update on ruling things outs, I mixed up a tank of e30 today and it made zero difference in the knock that its reading so I think its safe to say it is not fuel related.
 
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downshifting or part throttle knock reading is fine and expected. You should only be concerned at WOT, that is where real damage can occur.....unless you're hearing an audible issue or the engine is missing at part throttle. That would be more serious.

Your sig also says down pipes and cat-back, most aftermarket get rid of flex pipes, you can see knock from exhaust vibration then.
 

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downshifting or part throttle knock reading is fine and expected. You should only be concerned at WOT, that is where real damage can occur.....unless you're hearing an audible issue or the engine is missing at part throttle. That would be more serious.

Your sig also says down pipes and cat-back, most aftermarket get rid of flex pipes, you can see knock from exhaust vibration then.
Except when it's maxing out and pulling lots of timing and causing the OAR to rise substantially. Because, regardless of whether that knock is real, you're feeling the effects of it. Truck gets sluggish and won't perform until you lift and try again.

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Wait a few more drive cycles then report back.

Mine has good days where I'll see mostly negative KR then others ill be spiking positive all day long.
 

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Discussion Starter #94
Except when it's maxing out and pulling lots of timing and causing the OAR to rise substantially. Because, regardless of whether that knock is real, you're feeling the effects of it. Truck gets sluggish and won't perform until you lift and try again.

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Exactly and that’s my issue, I don’t expect knock readings to always be zero or negative but my problem is the get so bad so often that my oar has a hard time ever getting out of the positives and feels like I’m driving a detuned stock truck as a result.
 

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Right. I think we've established that most of us with this happening aren't worried about it blowing out engine up. It's just annoying and causes odd driving characteristics. If the knock is spiking on tip in, continuing to tip in does not result in any extra go-go. The truck just kinda says not today kemosabe. I think I've even heard the wastegates opening and bleeding off boost.

I can usually let off and go again and it's back to business as usual, or instead of continuing to tip in gradually, sort of stab the gas and it will clear up.

That's why I roll my eyes every time we have this conversation and people say "don't worry about it".

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Exactly and that’s my issue, I don’t expect knock readings to always be zero or negative but my problem is the get so bad so often that my oar has a hard time ever getting out of the positives and feels like I’m driving a detuned stock truck as a result.
If you are convinced it is a false knock, consider what I did ... lock out the OAR! You will still see +/- KR while driving and it will still adjust the overall Spark Advance. But it won't adversely adjust the OAR and pull all your power away when you least want it.

I have been running with my OAR locked out for a few years and I have had absolutely no issues.

OAR is fine, if you are not experiencing false knocks and have good gas in your area. But when you have false knocks, even when running higher octane (E30+), the OAR is only ruining your performance. Time to ditch it.

Many vehicle PCMs/ECMs have ran fine for decades without any OAR/LOR and just using the KR for immediately knock changes. With the OAR locked out, you are still safe while driving as the KR will still work. Locking out the OAR is just eliminating something that isn't working properly on your truck.

I no longer have "good days/bad days". It performs consistently all the time now (excluding changes due to ambient temperature).
 
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There's more to it than that. The OAR doesn't drop immediately. While the knock event is occuring, the OAR is steady. It's after that is over that the OAR drops in response to the knock spike.

Even aside from the OAR, it's a problem. Locking out the OAR I think would help, but I think @Boostking told me he's not a fan of that idea. Anyway, it may help, but it doesn't help in that moment when the truck is falling flat due to the knock spike, real or not, where you must lift and then reapply throttle to get it to go.

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Discussion Starter #98
There's more to it than that. The OAR doesn't drop immediately. While the knock event is occuring, the OAR is steady. It's after that is over that the OAR drops in response to the knock spike.

Even aside from the OAR, it's a problem. Locking out the OAR I think would help, but I think @Boostking told me he's not a fan of that idea. Anyway, it may help, but it doesn't help in that moment when the truck is falling flat due to the knock spike, real or not, where you must lift and then reapply throttle to get it to go.

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Yes I will talk to Brett about how to approach it and what works for him. Mine might be different in that case though, my OAR I can watch drop the second I see the high knock readings come up. Also I can lift and re apply the throttle as many times as I want it almost always just keep doing it until I really put my foot into it and get it to downshift or reapply the lightest throttle possible.

With the knock still occuring with e30 it seems pretty safe to say its false I would assume. Looking at logs though I think I will have to get through this tank of e30 while driving pretty slowly as the frp actual takes a pretty big dip from desired whenever I get into it.
 

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The issue here is not necessarily the OAR. It's the elevated spikes in KR.

Truck drives fine with a less than desirable OAR. It does not while the knock sensors are pegging the max.

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