Popping Noise at WOT on 05

[CStraface]

I know I have posted before on same subject, and I know there are other threads about the same noise... but I have seen no real answers.





Ok so TST is on 2/2 and I have this terrible popping noise coming from the engine at WOT.



Rail Gauge never goes below 15000 at WOT and will climb up to about 19000 or 20000 after the first second or two at WOT.



I have heard that a big wide open exhaust will amplify engine noises? But the sound still doesn't seem right.



Could it be my injectors? Something else inside the head?



I think the engine is getting enough fuel, I have GDP's fuel system, BDDL on Performance Level, and TST on 2/2.



Does not make sound when the TST is pulled off the truck. Any thoughts?

 

[lmills]

Won't make you feel any better, but I found my popping noise that I fought for the longest time..... It was from losing compression on 3 cylinders in the form of a blown headgasket. Hopefully for your sake it is not that serious. But on mine, I was just relieved to have finally found it.

 

[CStraface]

I dunno I wouldn't think I would have a blown head gasket, no oil comming out from around gasket. How else can I check????? I am studded and my wastegate is set at 40.

 

[cerberusiam]

Isn't 15k psi at WOT a little low for a system that should be at 23-24k max then settle in aroud 21k?



No Stage 2 CP-3? I wonder if that isn't too much duration for the flow. FCA not working right? Rail pressure relief valve not holding?



If your gauge is correct it sure sounds like the rail is going dry.

 

[CStraface]

Rail is capped... still trying to save up for stage 2. I was just surprised the rail is run dry on 2/2 and Performance on the BDDL. No problem when running one or the other. I guess a CP3 is really worth the investment.

 

[lmills]

OK. When you say a terrible popping noise, can you describe it a little more? Is it a rapid popping noise? Does it do it with the TST on other levels? The only reason I am thinking it is not rail pressure is because I have pulled mine as low as 14K in the past and never had a pop. Piers also noted once that as long as he had 16K in the rail, the truck produced good power. Once it dropped below 16K it started getting hot quick. On the other hand, when I had my stock CP3 with stock injectors, I never pulled mine that low either. Mine held pretty consistent to 23K. It never dropped as low as yours is until I went with bigger injectors.





Just an FYI... ... Mine breached between cylinders. I had no coolant loss or oil/coolant exchange.

 

[CStraface]

The poppping can best be described as a crackling... . like throwing bark in a fire place. Only constant and rapid at WOT. As rapid as say a automatic machine gun.



But you said it your self... "when I had my stock CP3 with stock injectors, I never pulled mine that low either. Mine held pretty consistent to 23K. "



So how come with my stock injectors and my stock CP3 am I pulling 15k-19k?

 

[cerberusiam]

Rail is capped... still trying to save up for stage 2. I was just surprised the rail is run dry on 2/2 and Performance on the BDDL. No problem when running one or the other. I guess a CP3 is really worth the investment.

I think that is probably the answer, stacking. I suspect the combination of the 2 is drawing the duration out enough to cause flow issues.



I have heard others having the same issue. Does not happen on all trucks and combinations so it is tough to tell what is causing it. I wonder if there are some CP3's that just don't flow as much as others for whatever reason.



Might try a dual rail feed kit and see if that makes a difference. It would at least tell you if it is a flow problem past the pump.

 

[lmills]

Dual feed rail will not help. I am telling you, I highly doubt it is fuel related.

 

[lmills]

The poppping can best be described as a crackling... . like throwing bark in a fire place. Only constant and rapid at WOT. As rapid as say a automatic machine gun.



But you said it your self... "when I had my stock CP3 with stock injectors, I never pulled mine that low either. Mine held pretty consistent to 23K. "



So how come with my stock injectors and my stock CP3 am I pulling 15k-19k?

possibly lower inlet pressure to the CP3?

 

[CStraface]

I think it's just time to invest the stage 2. Hopefully that takes care of my problem, if it doesn't, then I'm really up a creek... but at least I found the excuse to finally spend the $1100 on the pump

 

[CStraface]

possibly lower inlet pressure to the CP3?

How do I lower inlet pressure to the CP3?

 

[CStraface]

I wanted to check low end pressure to make sure the walbro didn't crap out, but my low end was fine... .

 

[Summit]

I talked to mark @ TST a couple months ago about this problem on my truck.

he said i'm either draining the rail or with my stacks i have too much timing. i found that the colder it gets the worse it has become,

i also took the downloader out, unhooked the rail pressure box and somtimes it will pop on 1/0 which mark said is timing only. mine will ONLY pop with the TST,, sometimes i can go 4/3 and no popping other times 1/0 will pop? 9 times out of 10 it wont start popping until im lifting out of the throttle at the end of a run, very seldom does it pop under load.

I havent put my finger on it yet.



lmills, ive wondered about that since the first day it popped, but i think it would pop with my other stacks too,,,i hope.

 

[lmills]

Cant say I have ever heard of it popping once you let out of the throttle.

 

[lmills]

How do I lower inlet pressure to the CP3?

No I meant possibly your pressure going to the CP3 is lower than I keep mine.

 

[RobertP]

the things that will cause your truck to pop are, head gasket, lack of fuel from cp3 or relefe valve or injectors, too much programing and draining the rail, elecronics are bad and defueling the truck--ecm and sensors.

 

[Summit]

Cant say I have ever heard of it popping once you let out of the throttle.

as im rolling out, not after i've lifted, say between 1/2 & 1/8th throttle.

 

[CStraface]

the things that will cause your truck to pop are, head gasket, lack of fuel from cp3 or relefe valve or injectors, too much programing and draining the rail, elecronics are bad and defueling the truck--ecm and sensors.

Well then lets narrow them down... .



1. my head is studded and wastegate at 39-no oil seeping through at any point visible to me from gasket, so this wouldn't be my number 1 prognoses.



2. We have already established it could be lack of fuel as when I run only one box, no popping occurs.



3. I don't think it is my injectors because of number 2... The truck wouldn't run perfect on one box vs. two boxs, if it were the injectors.



4. Relieve valve is capped compliments of Rich Brown. When we first established that there was a prominent popping noise coming from the engine, we decided to cap it... obviously did not fix our problem...



5. I couldn't tell you either way if it has something to do with the ECM or a sensor... I know that I have not thrown any codes that have caused a drop in HP.



I was throwing overboost when I was running the BDDL while my TST was getting a new harness. But that code is gone now that I have my TST back on. I threw a Crank. Per. code when I hit my speed limiter, but truck didn't loose any HP. Other then those two codes, truck has been fine electronically.

 

[lmills]

Head gasket wasn't my number 1 prognoses either since I had mine studded also. However my truck acted exactly as you describe to the "T" Also boost is not the only thing that will take out a head gasket. Increased cylinder pressures from too much timing will kill them just as fast if not faster. And there are planty of stacked vehicles running around that have blown headgaskets to prove it.



Don't get me wrong, I liked my trucks power when it was stacked. You just have to keep an open mind about the mods and what they can do



I would start with a leak down test or compression test. Maybe even try retorquing the head