False knock between shifts?

[Kman11]

Hey guys,

I'm chasing some false knock, which shows between shifts.

I checked all the exhaust bolts, everything has clearance and is tight.

I did have a meth injection kit installed, and i was not getting the knock initially - about 2 weeks after the install the false knock showed up. Only happens between shifts. If i do a pull in one gear logs show negative knock.

I'm obviously guessing the knock is coming from some component of the meth injection kit tapping somewhere.

One of my braided lines looks like it could be tapping one of the a/c lines - should i be looking for anything potentially touching that ultimately makes it way back to the engine?

Any ideas of things to look for outside of the meth kit that you guys have dealt with before in case it's unrelated?

Many thanks,
Jesse.

 

[Famine]

Pics of the setup? How is it mounted?

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[Kman11]

I'll post some pics up tomorrow. The pump is mounted very close to the a/c condenser, but doesn't appear they are touching when the motor torques.

I cushioned / zip tied everything i could see under the hood related to the meth kit which could be rattling/banging and the false knock is still happening.

It's really bad from 1st to 2nd shifts, pretty bad from 2nd to 3rd, and almost non existent from 3rd to 4th shifts. I'm on 3.31 gears BTW.

I'm going to crawl under the car again this afternoon and triple check the exhaust clearances around the rear end.

Thanks for help!

 

[5lho]

Anything touching anything can set this off. Do start with the last thing you touched, as that's probably where the issue lies but don't limit yourself to that. Even plastic contact can do this, in the right circs.

 

[Kman11]

Anything touching anything can set this off. Do start with the last thing you touched, as that's probably where the issue lies but don't limit yourself to that. Even plastic contact can do this, in the right circs.

Thanks for the advice!

This has been very frustrating to say the least.

I've double and triple checked everything. I did some more testing today, it's definitely happening only when the first drive-line shock happens from going WOT.

For instance-
* If i down shift to 2nd or third at ~4krpm or so and go WOT, instance knock 9+
* BUT if i'm in 3rd at 2k rpm and ease in the throttle to WOT, stay WOT it goes -6 knock all the way to 7k.

* It's even happening now at part throttle when i stab the throttle at low rpm, showing ~2-5+ knock. (so it appears it's gotten worse)

I'm detecting some sort of vibration, i think it comes from the rear.. really hard to tell... Vibration is happening in gear and in neutral rolling.

Also my brakes feel weird, but not sure if that could possibly be related.

At this point i'm thinking it's either -
* Drive shaft related?
* Rear suspension (everything looked fine here to me)
* Rear end - bent axles maybe??
* Transmission?

I'm going to call my mechanic who rebuilt the rear end a year ago and did my drag suspension / set the pinion angle etc. I'm in dire need of a 2nd set of eyes at this point LOL

 

[Kman11]

Took another look under the rear of the car tonight - Found the adjustable upper control arm nut's to be loose (ones to adjust it).

This would make some sense to me, if the pinion angle moved, it would explain the vibration and i would think it could cause a bang or something that would set off the knock sensors.

Am i off base here, or do you guys think that is a good possibility?

I can't adjust the pinion angle myself, i'm hoping my mechanic can look at it this week.

 

[Sportin' Wood]

I had a jam nut come loose on my adjustable panhard bar and it rattled and vibrated like an sob, so I'd say a good chance you may have it.

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[Sportin' Wood]

Off topic, but what meth kit are you using? I'm just getting ready to install a snow kit and was planning to install my pump behind the bumper cover, below the pass side headlight near the washer jug to try to keep the vibration isolated. Are you sure your pump is not coming in contact with anything?

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[Kman11]

Off topic, but what meth kit are you using? I'm just getting ready to install a snow kit and was planning to install my pump behind the bumper cover, below the pass side headlight near the washer jug to try to keep the vibration isolated. Are you sure your pump is not coming in contact with anything?

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I have an alky control kit. See the picture below for pump placement. The kit is really nice, and the owner of alky is super informative / helpful with any questions. I can't recommend him enough.

The pump is close the a/c pulley, but it's not contacting - i confirmed this.

 

[97snakebite]

Took another look under the rear of the car tonight - Found the adjustable upper control arm nut's to be loose (ones to adjust it).

This would make some sense to me, if the pinion angle moved, it would explain the vibration and i would think it could cause a bang or something that would set off the knock sensors.

Am i off base here, or do you guys think that is a good possibility?

I can't adjust the pinion angle myself, i'm hoping my mechanic can look at it this week.

Sounds like you're getting close. I checked there first then check the entire drive train

 

[Kman11]

Figured i would update this -

Mechanic went through rear end, rechecked pinion angle, made sure all suspension related items look good.

Knock sensor showing knock still when throttle is stabbed / hard shifts.

THE NEW development is the knock sensor shows knock when the engine is revved quickly at a stand still.

Ughhh this has a been a frustrating one, i'm left with a few possibilities-
* Pulleys / water pump / tensioners etc?
* Internal engine issue?
* Faulty knock sensors?

I can take the procharger belt off and run the car to see if it's related to that tensioner..

If i take off the regular belt, how long is it safe to run the car? The water pump would not be spinning.. Not to mention the alt won't be spinning.

 

[Kman11]

If it's of interest i pulled all the plugs today to see if there was anything odd there. While tuning for the meth it was running 1/2 a point to 3/4 a point rich, we mixed in water and was able to get it much closer to optimum, still a little rich though.

Any chance that running way rich could screw up the plugs and cause an issue?

Attached are 1 picture of each plug, i have no clue what to look for.

Thanks guys!

 

[Kman11]

Another quick update - I have a friend who is a mechanic, he used his scan tool and could see the two knock sensors. Knock sensor 1 was picking up the high amount of knock when revving, knock sensor 2 was moving only slightly.

Anyone know which side of the motor knock sensor 1 is on?

We took the blower belt off and ran it, still knock when revved/no load.

Listening with a stethoscope to everything we could think of, no dice. Listened to the engine all over, nothing sounds odd / off.

Drove it around a bit tonight for some more data logging. Under a load it only shows the knock at first throttle, if you keep it floored it slowly add's timing back in.

Sometimes it does go WOT without knock, and it run's great all the way to 7k(where i normally shift).

If there was an internal engine issue, do you guys feel it would be obvious at this point?

Any chance it could be the knock sensor itself? It appears to be a bit of work to get at them. I'm debating going that direction.

I can tell you all, whatever is causing this, i'm very much looking forward to finding what it is, it may save someone else a headache in the future!

 

[5lho]

You could just replace the emotional knock sensor and see if it helps. 1&2 are always in reference to the number 1 cylinder side. #1 is on the pass side front. The KS are under the intake manifold. You'll need to pull all that to get at them; maybe an hour's work total. I found one unplugged on my car, from the factory. WTG Ford.

the pulling the belt idea is something i always do first, as it isolates the accessories from the engine. problem still there? It ain't the accessory drives. You can run it for a few minutes no problem with the drives unbelted; no booting it through the gears though. just watch the temp gauge.

A quick scan of those plug pics shows the typical residue of normal combustion on 10% ethanol pump gas.

 

[Kman11]

You could just replace the emotional knock sensor and see if it helps. 1&2 are always in reference to the number 1 cylinder side. #1 is on the pass side front. The KS are under the intake manifold. You'll need to pull all that to get at them; maybe an hour's work total. I found one unplugged on my car, from the factory. WTG Ford.

the pulling the belt idea is something i always do first, as it isolates the accessories from the engine. problem still there? It ain't the accessory drives. You can run it for a few minutes no problem with the drives unbelted; no booting it through the gears though. just watch the temp gauge.

A quick scan of those plug pics shows the typical residue of normal combustion on 10% ethanol pump gas.

Thanks for the help!!

I took off both belts today (i never had the a/c belt on to begin with) and ran it briefly, when revving the knock was showing. So that eliminates pulleys etc.

While the blower belt was off (and i disconnected the fan), i did notice there is a bit of a ticking noise coming from the passenger side of the engine. I was alone so i couldn't pinpoint it, but noticeable tick. You could only hear it from 900rpm to 1600 or so, then it wasn't audible anymore. At idle no tick, only that first soft rev.

I did hear this same tick a few times over the past couple of years, once when i was at the track - i recall that time vividly - this was all before the SC. The ticking sound seemed to go faster with rpm, but again you could only hear it at low rpm's.

In the past the tick was there, then would go away. Timing did seem to be around oil changes ( just had one this week).

Still not sure if the tick is related to the knock sensor issue - but who knows!

 

[5lho]

Well, you've learned something at least. An engine tick could really easily be detected as knock by the ecm. That's exactly the kind of sound it's listening for. Search around for the myriad of tick cures here and elsewhere to see if you can remedy it.

 

[Kman11]

I figured i would update this..

I had another issue arise where the car would run really wierd when first started and cruising around. Turned out the meth kit was siphoning through to the intake pipe. I put in a high pressure check valve which solved that issue.

Back to the knock - I'm left scratching my head still. I've been doing a ton of datalogging. Sometimes it knocks really hard (6+) on WOT hit, sometimes it knocks around 2 on the hit, and sometimes none. If i ease into the throttle and got WOT there is no knock, it goes -6 typically (while on meth).

So yea i have no idea at this point. I'm left with pulling the manifold to see if that sensor is loose, or replace them both to eliminate them from the equation.

If anyone has any out of the box idea's, i'd love to hear them!

 

[Kman11]

Still playing around with this one - I've had 3 or 4 ah-ha that must be it moments so far, to no avail.

Anyone know what kind of sound the knock sensors are looking for?

We had the car idling tonight on a lift, and were banging the exhaust, suspension, everything, trying to get a reading on the sensor, nothing.

I even took a super long screw drive and tapped the sensor itself (can see it through the intake manifold). Tapped all around it, nothing. With all the threads taking about loose exhaust causing false knock, why can't i recreate that by literally banging on the exhaust, engine, etc ?

It would seem to me it's looking for a vibration of sorts, not a tapping sound?

Anyway i ordered new knock sensors and i'm switching them out Friday to eliminate that from the list of possible causes, and i'm not confident it will help at all.

Is there anyway the MAF could have anything to do with it(if it dirty)? How about a voltage issue? Grounding issue? Just trying to think outside the box.

 

[Kman11]

Hey Guys, still have not resolved this..

I have tried -
* Paid mechanic to check rear end gears/diff, all good.
* Found loose upper control arm, tightened.
* Found 3 loose header bolts (stock manifolds), tightened these
* Found brake rotor was moving on studs, replaced
* Messed with exhaust 100 times, put stock axle back on etc
* Changed knock sensors, and installed plastic washer between them and block.
* Cleaned MAF
* Changed spark plugs

Issue it still there. Sometimes it goes 10 KR under soft shifts when cruising. Anyway this could be some crazy glitch?

I'm approaching the end of my patience with it. Seems like i'm trying to catch a ghost. It honestly makes me want to sell the car and buy something without knock sensors LOL.

And i still don't understand what sound the knock sensor is looking for? Like i said before, i can bang on the sensor itself, exhaust, etc and get no reading.

I found a member on here who had pretty much the same issue in 2014. I sent him a PM and asked if he solved it, he said Nope i sold the car!! LOL

 

[Kman11]

Oh and i had this code pop up last week - P0315. Crankshaft Position not learned.

I looked it up, it appears to be something that will go away on it's own? I have put quite a few miles on it, has not cleared.

Any thoughts if this could be related?