Engine Knock?

[BoostedCocaine]

I was accelerating the other day to exit the highway, nothing crazy, and my mustang threw a code for "Turbo/Supercharger Underboost". Shortly after, I started hearing this sound. Any ideas what the issue may be?

[ame]

2015 Ecoboost premium with 20k miles.

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[TheLion]

I was accelerating the other day to exit the highway, nothing crazy, and my mustang threw a code for "Turbo/Supercharger Underboost". Shortly after, I started hearing this sound. Any ideas what the issue may be?



2015 Ecoboost premium with 20k miles.

That's definitely not knock. Sounds like valve noise to me, but could also be injector noise. There have been some issues with the injectors on 2015's EB's and also ST's and F-150's. It may or may not be related to the low boost condition. Here are some listed causes of the P0299.

Intake (induction) air restriction or leak Failed or damaged turbocharger (sticking, binding, etc.) Faulty boost/charge pressure sensor Faulty wastegate bypass regulator valve (VW) Low fuel pressure condition (Isuzu) Sticking turbo nozzle control solenoid (Isuzu) Faulty injector control pressure (ICP) sensor (Ford) Low oil pressure (Ford) EGR system fault (Ford) Variable geometry turbocharger (VGT) actuator (Ford) VGT vanes sticking (Ford)

Read more at: http://www.obd-codes.com/p0299
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[TheLion]

Could also be piston slap, but that is uncommon on modern gasoline engines unless there's an issue with the rings not seating properly / damage / excessive wear.

Given that it's a cyclical metallic clank sound, injectors or valves would be the most likely culprits, although the EB's are clanky when you turn them off. Was that sound when the engine was turned off / on only? It was hard to tell from the video. Some valve / injector ticking is normal. Again, it may not actually have anything to do with the low boost condition.

I'd check the piping. My OEM piping was not tight, while installing my Levels IC I actually caused on to disconnect with just moderate force. I think their torque spec on the band clamps is a bit low from the factory. That would be the most likely culprit of low boost. Next would be the waste gate.

 

[BoostedCocaine]

Could also be piston slap, but that is uncommon on modern gasoline engines unless there's an issue with the rings not seating properly / damage / excessive wear.

Given that it's a cyclical metallic clank sound, injectors or valves would be the most likely culprits, although the EB's are clanky when you turn them off. Was that sound when the engine was turned off / on only? It was hard to tell from the video. Some valve / injector ticking is normal. Again, it may not actually have anything to do with the low boost condition.

I'd check the piping. My OEM piping was not tight, while installing my Levels IC I actually caused on to disconnect with just moderate force. I think their torque spec on the band clamps is a bit low from the factory. That would be the most likely culprit of low boost. Next would be the waste gate.

I'll check the piping later tonight. I swapped the intake and that didn't change anything. The sound is most noticeable around 2k rpm while brake boosting or driving.

 

[TEXAS HEAT]

I'll check the piping later tonight. I swapped the intake and that didn't change anything. The sound is most noticeable around 2k rpm while brake boosting or driving.

You possibly "popped" a boost hose loose. Brake boosting/load boosting will definitely uncover any loose or weakened clamps/hoses.

I'm pretty sure the low boost CEL is a delta reference reading between the TIP and MAP sensors. Your likely making good pressure at the turbo and somewhere in the intake track you have a leak which results in lower boost at the throttle body therefore generating a code. Definitely double check all of your connected hose fittings and clamps.

However, that does sound mechanical though...:shrug:

 

[Fast64ranchero]

Doesn't sound good, I'd guess Rod, piston pin or timing chain. I can't think of any way it could be boost related, unless it lost a ring land and the turbo ate it. It's RPM related so I'd take it serious.

 

[85stang]

Its probably the boost pipe rattling around because it came loose. common for them to be loose and pop off on the '15 cars

 

[BoostedCocaine]

Checked the charge pipes and they're still connected. Also, the sound is present even when i'm not in boost. I'm still able to make power but the sound is pretty concerning.

 

[TheLion]

Checked the charge pipes and they're still connected. Also, the sound is present even when i'm not in boost. I'm still able to make power but the sound is pretty concerning.

Is your car stock? If so I HIGHLY doubt it's a rod or bearing. The bottom end is VERY stout and if your car suffered damage from an knock or super knock event the piston / rings / lands would have failed before the rod.

It's unlikely a timing chain either as the chain has a hydraulic self adjusting tensioner that takes slack out of it. If the chain failed completely your car wouldn't be running.

I would really take a look at injectors and valve train. It's a cyclical noise that follows rpm linearly. The turbo rotation is in the HUNDREDS of thousands of RPMs at speed, even at low boost were talking tens of thousands of rpms. If something was binding in the turbo it would manifest as a continuous sound, most likely a squealing / grinding of metal on metal.

This is a cyclical tick / tap, very much like valve or injector noise. I would get a mechanics stethoscope and see if you can pinpoint the location of the noise. Cost about $20~$30. Then I would take it into the dealer if it's under warranty, but going in armed with as much knowledge as possible will help you get the most expedient and proper service.

Only other thing I can think of other than the above two is again, piston slap, but this is rare on modern gasoline engines (common on diesels due to tolerance requirements) and would most certainly indicate an issue with the piston rings. Could be a bearing failure as well, but again that's highly unlikely as the bottom end is very stout and save oil starvation, pistons usually give during knock / super knock before anything on the bottom end. I wouldn't expect a stock car to be knocking however...

In my experience dealers are more willing to work with knowledgeable and well informed, polite customers than ignorant and demanding ones. They are also less likely to tell you bogus guesses as to the problem if they don't think you will buy into it.

 

[TEXAS HEAT]

Double check your Diverter Valve. If it's compromised, it may cause a low boost symptom and valve may be mechanically clicking.

That sounds like bearing noise, could be an accessory like water pump, alternator, idler, etc. That would be very RPM dependent.

 

[TheLion]

Double check your Diverter Valve. If it's compromised, it may cause a low boost symptom and valve may be mechanically clicking.

That sounds like bearing noise, could be an accessory like water pump, alternator, idler, etc. That would be very RPM dependent.

Another good point, these are all things to check. When solving problems, it's best to start with less critical and simpler causes first and work your way up to more complex and indepth causes if the simpler things don't turn out the be the root.

 

[Edkiefer]

Its very hard to tell from you-tube vid, you need to be there and pin point area.
Anyway, it does sound like a bad hydraulic lifter, valve train issue, but could be bad VTC actuator too (these motors don't have hydraulic lifters AFAIK).
If low mileage bring it in, unless its highly modified

 

[EnFOURcer]

Thats a new one :shrug:

 

[Fast64ranchero]

Op let us know what you find out. Unlike the others, I'd say it's internal and serious, nothing in the vavle train that can "all of a sudden" start making noise except a cam phaser or chain issue. These bottom ends are weak, and you may be the first to have a still running but damaged bottom end. I built my engine on my kitchen table, so you might say I know them inside and out. (I know Red Neck). I can tell you it is way cheaper to repair if it is still running. Gets pretty expensive if you end up with a block like mine http://www.mustang6g.com/forums/showthread.php?t=53250

 

[King Jackmode]

Rod bearing. Makes itself known when it's loading up.

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