When I first installed my boost gauge (Autometer Z-Series, 0-35 PSI) it would move very gracefully and solidly; I would step on it, and the needle would go up smoothly.

A few weeks ago, however, the gauge started to flicker. As in, instead of increasing smoothly, it wags back and forth real fast. This only happens under hard acceleration and happens through the full sweep. As far as I can tell, the pressure readings haven't changed at all; the needle just is sloppier.

So is this a standard sign of the gauge getting "broken in", do I have a leak, or is the gauge/ turbo about ready to grenade?

Thanks for any more experienced advice.

 

Look for a leak and check to see if the turbo has gotten wobbly. If it's not that, the gauge has issues.

 

So it could be a wobbly turbo?

Wobbly turbo makes irregular boost?

 

My boost gauge has been pulsating worse and worse also. By boost is still maxing at 34, but the 3/4 load at lower RPM make mine really pulses. I am starting to worry about it. It's also really making a lot of noise now when I am under full boost and let off too fast. I hadn't noticed it until I was the passenger in my truck while my nephew jumped on it. The turbo noise is a lot louder on the passenger side!

 

how far does it fluctuate? have you added any fuel lately? sounds like it's surging more than anything to me. the best fix for that would be any stage of a high tech upgrade. or if you're good with the lathe, just cutting a MWE slot would do the trick too.

 

I don't know about Begle, but I did cut my fuel cone last month.....

 

i dont no if this is whats going on but i thought i would throw it at ya. when my truck was bone stock it maxed out at 15 psi, since then i have turned the fuel screw 2 turns bottomed my star wheel ground my fuel pin put in a bhaf 14 cm housing (non gated-mistake)and a 4 inch exhaust. with my turbo spooling much quicker and the very easy flow it causes my turbo to bark. barking is when the turbo makes funny noises and my needle jumps all over the place. this is caused because of at low rpms there is lots of fuel trying to be shoved into the engine under accleration. thus causing much heat without the air it needed to keep it cool. that heat (energy=heat) then spools the turbo more than normal. so at low rpms its trying to shove more air in the engine than what it can take, thus causing it to surge or bark because the air is getting shove back out the intake.

im really sorry if this makes no sense im not very good at explaining things but i thought i would try and help

 

That's actually a pretty good description, don't be so hard on yourself!

Is this a dangerous condition?

 

i'm not trying to nitpick you at all, here jake, but just to clarify, surge and bark are to very different animals. what you're describing is surge. barking is the rapid deceleration of the turbine shaft when letting off the go pedal too quickly for a shift after a full boost run. the same basic thing is happening though. all the built up pressure in the head, piping, innercooler and what not tries to go backwards through the turbo and you end up with the same problem of air trying to go two different directions through the turbo. it will be noticed as a very muffled wuf,wuf,wuf type thing. more like an approaching helicopter than a dog. anyway, like i said, not trying to nitpick.

dave

 

My truck is doing both. Do I need to address this issue, if so why? I want to do the stage IV anyway, but I have to have a good reason for the accountant (wife)!

 

Okay let me throw in what mine is doing too and see if that is what ya'll are talking about. At about 1300-1500RPM's if I give it WOT I will here some kind of noise from the turbo as the boost is building usually from around 15-20psi the boost guage will flicker just from around 15-20psi while the boost is building, if I let off the throttle or try to get it to do it longer it will quit it only does it for about 1-3 seconds at the most. If this problem is play in the turbo will an HTT stage IV kit fix it? And I have checked to see if there is any play and there wasn't so I am lost.


Chris

 

You can address the issue with your right foot, but who wants to do that?! Any of HTT's comp housings will help your flutter problem. The MAP slots are the cure. When big injectors and a heavy foot are combined with a smallish exhaust housing and low RPM's, more air volume/pressure is produced by the turbo than the engine can manage. The MAP slots allow some of that pressurized air to flow back into the intake, smoothing out the boost building process; widening the compressors' efficient boost range, hence the name. Tell the little lady it's either a few hundred now, or an HTB2 later (Don't tell her you're planning the HTB2 anyway, though!)

 

I don't know what turbo bark or surge sounds or feels like, and I've consulted in our DIESEL GURU Administrator WANNA on this, but it seems to stump us both. My truck has this annoying "purr" or "not so loud clatter" that comes on after the truck has warmed up. I hardly ever hear it 1st thing in the am, but after I've driven it for 1/2 hour and when it is good and warm, I can hear/feel it through the go pedal. It is worse when I have driven for 1 hour and when I pull into my driveway at the end of the day. As I tap, tap, tap the pedal at around 5 psi boost(45 mph) I can hear a purr, purr, purr. I have changed my lift pump, bled for all air out of the fuel, checked all fluid levels, sprayed my pressurized system for boost leaks, (even changed to all new intercooler boots)checked the exhaust system for loose hardware or leaks and I can't seem to locate it. I try and hear as best I can under the hood while the engine is running and it seems to be coming from the turbo area when under the hood, but while in the cab driving, I hear/"feel" it on the drivers side. What gets me is it happens after I've driven it for around 30 miles, no sooner. If this bit of info helps in diagnosing my problem, this turbo is a brand new hybrid HX 35 16 cm2 set up from Piers. Where else should I be channeling my efforts, guys? What does a bearing from a water pump that is fouling up sound like? Carmyne

 

I'm gonna stab way out in left field and say that when your tranny/engine mounts (more likely engine) get hot, they get soft enough to let the engine rock in such a way that the exhaust (downpipe, maybe) hits the frame. I know when I moved my DP back for the 12cm, I didn't put the bolt back into the bracket that goes into the bellhousing and the DP would rattle on the frame making a similar sound to what you describe. It'd only take a few minutes of looking at the exhaust for scrub marks, even if just to prove me wrong

 

Here is the main thread from back when Monty, J'eh, Dave and I started talking about this problem in our trucks: Turbo "flutter", aka turbo surge

A turbo from any of the later model trucks will really take care of the problem -- they all have Map Width Enhancement slots. I finally installed an HX 35 on my truck, and it took care of all my surge problems -- though it does spool a little slower than the stock H1c on my 3/4 ton truck.

Hope this helps,

Alec