DI Pump Noise?

[mustangpegasus51]

UPDATE: Seems like someone else has this noise; will add any info there: https://www.mustang6g.com/forums/threads/2018-mustang-gt-noise.140090/

Hey everyone,

Trying to document any odd sounds I hear so I can better know what's normal and what's not going forward.

Cold start today noticed a sound like two tiny metal balls clinking consistently:



Seen around forums this noise attributed to DI.

Can anyone out there confirm it's DI if they share this noise, or at least that it's common among healthy engines? Thanks!

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[Elp_jc]

DI is not working at idle, as an FYI. But the DI fuel pump is, since it's mechanically driven by one of the cams. And that very well could be that 'ball clicking' noise you mentioned... as well as the 2K rattle. At any rate, your engine sounds normal though, so I wouldn't worry about it. But not exactly sure what it is, to be honest.

 

[mustangpegasus51]

@Elp_jc yeah I'm thinking they might be normal sounds but are being produced in a weird context. I was able to play OBD detective to find out something is VERY wrong with the car, dealer seemed almost disturbed when I showed them the data lol. Dropping off Monday, I'll likely post the story when I get it back from them.

 

[GMONSTAH]

@Elp_jc yeah I'm thinking they might be normal sounds but are being produced in a weird context. I was able to play OBD detective to find out something is VERY wrong with the car, dealer seemed almost disturbed when I showed them the data lol. Dropping off Monday, I'll likely post the story when I get it back from them.

Any update?

 

[Cobra Jet]

@Elp_jc yeah I'm thinking they might be normal sounds but are being produced in a weird context. I was able to play OBD detective to find out something is VERY wrong with the car, dealer seemed almost disturbed when I showed them the data lol. Dropping off Monday, I'll likely post the story when I get it back from them.

Very wrong? Such as?

 

[mustangpegasus51]

Very wrong? Such as?

My fuel rail pressure would slowly creep up, can get up to 3000psi at idle. (Desired FRP at idle as far as I gathered is high 300's, 400 or so.) Took it to the dealer and they were as aghast as I was. They're working on it, will give updates as I receive them. I have so far had no codes that account for this, and had the wrench light come on between me noticing the FRP issue and bringing to the dealer. (The wrench light went away after a few restarts, but the other issues remain.)

The long term fuel trims also go negative under acceleration. The AFR goes lean when I accelerate, which is the complete opposite of what is supposed to happen.

To clarify with everyone though, not saying the noise is not normal, but maybe mine was making it more or louder than usual given the above circumstances. (If said noise is from the fuel delivery system.)

Given that the fuel pressure regulator is driven by vacuum, I looked into sources for umetered air. Then I noticed that my throttle position will dip on WOT, and surge when decelerating. (Like this video: ) My car was assembled within the date range of TSB 18B34 which mentions defective TBs, but the program expired before I purchased the car. Of course, it could also be another type of vacuum leak, or something else that mimics vacuum leak-like symptoms.

 

[mustangpegasus51]

So update...they said something about a brake booster sensor and if I recall, low fuel. This seems to fit my initial thoughts -- brake booster line could be a source of a vacuum leak, and I had stated the fuel trims go so rich on throttle that the PCM is sucking fuel during acceleration, and essentially hemorrhaging fuel during idle etc.

What frustrated me was that they were posturing that some problems may have come from using an aftermarket scan tool (a one-directional tool I bought off Amazon,) despite my issues happening long before I even bothered to buy one. I know computers pretty well; maybe it shows a code saying I used one, but it seems doubtful that a read-only device would cause any actual issues. If I was using a bi-directional tool or function at the time, maybe an issue could arise, but for these diagnostics I'm simply reading data. But in either case, the data speaks for itself.

They also said it was operating normally after resetting the PCM. I reckon once the fuel trims adjust it will be rough again.

Despite having some disagreements here and there, this dealer is still trying to resolve the issue, and I commend them for trying.

 

[Temovic55]

So update...they said something about a brake booster sensor and if I recall, low fuel. This seems to fit my initial thoughts -- brake booster line could be a source of a vacuum leak, and I had stated the fuel trims go so rich on throttle that the PCM is sucking fuel during acceleration, and essentially hemorrhaging fuel during idle etc.

What frustrated me was that they were posturing that some problems may have come from using an aftermarket scan tool (a one-directional tool I bought off Amazon,) despite my issues happening long before I even bothered to buy one. I know computers pretty well; maybe it shows a code saying I used one, but it seems doubtful that a read-only device would cause any actual issues. If I was using a bi-directional tool or function at the time, maybe an issue could arise, but for these diagnostics I'm simply reading data. But in either case, the data speaks for itself.

They also said it was operating normally after resetting the PCM. I reckon once the fuel trims adjust it will be rough again.

Despite having some disagreements here and there, this dealer is still trying to resolve the issue, and I commend them for trying.

Any updates ? Did you find the source of that issue ? My car is in the shop for diagnostics! Checked with smoke test, spark plug gap to spec, probably swapping the FIC1000 injectors to the OEM to see if the BAP is failing ! I've got a data log to be sent to VMP and some well known tuner to determine if this is really a tune rather than a mechanical issue.

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