Shaft Play in & out .030" okay & Sluggish When Hot

[shane02pro5]

I have had a slight whine sound usually only audible at low rpms cruising or tapping on the throttle cable. Does the turbine spin a little with the wastegate closed? I checked for shaft play and have no wobble but maybe .030" in and out. Spins perfectly free and quiet.

I have had my Hiboost kit on my P5 for 3yrs. and 60k miles now and just this summer I have noticed in the middle of the hot day it is more sluggish getting into boost and won't hardly hold an idle once the engine is up to temp when the a/c is loading down the engine. This is when I started thinking the whine may have been associated.

Any ideas??

 

[ddogg777]

I think what you meant to ask is does the turbine spin when the wastegate is open. Because when it's closed, it spins uber fast. It will spin open as well because there will always be exhaust gases passing over the blades, it just won't build much pressure behind it because gas follows the path of least resistance--through the open wastegate.

 

[ddogg777]

Now, it sounds like your wastegate is getting stuck closed and causing the turbo to spin up somewhat at idle. This would also cause your engine to bog because it's restricting the exhaust flow of idle gases.

Edit: Nevermind, I wasn't thinking correctly, the wastegate should be closed at idle and low boost.

 

[shane02pro5]

I was thinking it was leaking slightly allowing it to spin at idle and also cause it to build boost a little slower. Thing is; it doesn't do it unless it's extremely hot out like lunch time after it's warmed up. I was trying to pull apart the manifold to check the internal wastegate door but could not get one of the bolts to loosen because it's in a tight spot. I am going to grind on a wrebch to give it clearance to get in there and check it out today.

 

[igdrasil]

all turbos will spin @ idle...even BIG ASS turbos fitted in small engines.

Wastegate is always closed on idle.

 

[ddogg777]

And since they spin up to like 60,000 rpm, you can't really tell what can be wrong with it with just a simple spin.

 

[shane02pro5]

Thanks for the replies guys. I haven't had a chance to check my wastegate door but I'm sure the turbo and wastegate are okay. I am hitting 10psi at 4k at all time but mid-day HOT. Pretty sure that's about right, but after 60k miles I've never really noticed exactly where it's always been. The wine is faint only at low rpm's and can't be heard above around 2500 rpms. I figure the .030" in and out shaft play is okay since no one commented on that???

I am going to contact J&S to see if I could be knocking and my LED is just so dim I can't see it. I know when I drop under 1300 rpm's it is normal for the LED to flicker and when it does it is very visible. Maybe slight knocking is not as aparent. I noticed at lunch 2nd gear is like a slug until like 4500rpm's which is where J&S would be putting timing back.

Any ideas on the idle dropping off with the a/c on full blast?? I'm sitting at idle middle of the day hot. It will idle for like 5 minutes at around 18-19in/hg (21in/hg with a/c off and no monster a/c fan pulling on the electrical system) then jumps to like 16 then just falls off and dies as if a pressure switch just blew or something but I've checked them all. Usually it would drop[ and the idle control motor would catch it before it stalled. Now it doesn't even try. I guess I need to check that also!

Next step after IAC I guess for the third time I will pressurize my intake and check for boost leaks. Last time I had one in the back between the top and bottom halves and then at 2 of my injectors.

Once again thanks for the input!

 

[igdrasil]

no check engine?

The in and out shaftplay is not good.

 

[shane02pro5]

no check engine? No

The in and out shaftplay is not good.

s***! Not what i wanted to hear. Even at .030"?
I just thought the whine would get louder with boost. If the whine was from toasted bearings at low rpms, in boost it would be very loud, wouldn't it?

 

[shane02pro5]

No check engine light.

 

[shane02pro5]

Yesterday after work going to pick up my kids and the car would not hold an idle for more than 5 seconds. A/C on at any setting would make my vac go from 20in/hg to 16 instantly and stall out.

This morning ran awesome and idled perfectly. Man this is driving me crazy!!

 

[shane02pro5]

Frayed wire on IAC solenoid. Idle fixed!

 

[Maxx Mazda]

Still get your turbo rebuilt. It's an exponential problem. The longer it stays like that, the worse it gets until it will spin out of a bearing and hit your compressor housing like mine did. Rebuild now while it's an easy fix, or it could be MUCH more costly down the road...

 

[shane02pro5]

I don't think the VF22 is rebuildable. I have read that everywhere I looked unless maybe they just don't make a kit for it. I sent a PM to Juan from Hiboost inquiring about. It is a very faint sound and has been that way for 10k miles and can't be heard above cruising at 30mph over 3k rpm's. I used seafoam in my oil (and intake) before every oil change just cruise under 3k rpms for about 1 mile then idle for 10 minutes and change it. I thought it may have caused a build up that has mostly been freed up. It is not as constant anymore and definately has not hurt performance YET. I also haven't had the sluggish feel lately since changing my oil. Maybe carbon build up causing slight detonation triggering the J&S even though the LED never showed it. I will be getting tuned in the next couple of weeks so maybe that will help shed some light on things.

Thanks for your responses. By the way, what turbo are you running that had to be rebuilt and why?

 

[Maxx Mazda]

Thanks for your responses. By the way, what turbo are you running that had to be rebuilt and why?

Garret T3 60 trim, too much shaft play spun the shaft out ofthe bearings and hit th housing. It won't take long.