Garage Storage Organization and Garage Cabinets

89CSX#179 · **Boost issues**

This is about my VNT, I did'nt know whether to put it in the VNT section or this section, this section is looked at more so here it is. The turbo is very high pitched, it over boosting like a mother, and it isn't cutting out ( I got the gauge to where it doesnt move anymore!). It builds boost extremely fast, and really doesnt have any power when it does boost.

Here's the thing:
No codes at all, no overboost cutout. We went through the Chrysler VNT overboost trouble shooting tree, all we have to do now is test the MAP sensor, but everything else we have done has fixed nothing.

HELP!

GLHNSLHT2 · 10-19-2005, 10:37 PM

if it's screaming it's probably rubbing the housings. Sounds like it's on it's way out. And from the way you drive it in your stories I wouldn't be suprised. VNT's don't like to be beat on.

89CSX#179 · 10-19-2005, 11:12 PM

it only has 7K miles on it at the most. and what is rubbing housings exactly? Note that the actuator arm is fully functional and not stuck, no vacuum leaks. Before I reset the codes it did say code 37 or 38 I can't remember now but that code isnt there now. And what you mean the way I drive it? Im not saying i dont race, I think I have like 6-7 races on the first 3 pages on the street stories section, and there is maybe 3 or 4 I havent posted, but it isnt like I drive it like that everywhere, just when I race.

OmniGuy123 · 10-19-2005, 11:15 PM

The compressor or turbine wheel would be rubbing the housings. I had that happen to me when a tII turbo was going south. It sounded like a really high pitched vac leak screaming away when in boost.

87GLHS232 · 11:31 PM

Quote:

Originally Posted by 89CSX#179

but it isnt like I drive it like that everywhere, just when I race.

And he races everywhere!
Seriously though, I think he was talking about the turbine blades hitting the housing. If so your not long from real problems.

89CSX#179 · 10-19-2005, 11:44 PM

and this can just happen for no reason, jus bad luck?

89CSX#179 · 10-19-2005, 11:44 PM

AND this can cause the overboost and lack of power? What about my lack of codes and boost cutout?

87GLHS232 · 10-19-2005, 11:58 PM

I would imagine the blades hitting the housing would slow the turbo, so yes, it could cause lack of power.
Theres always a reason. Weather it is a poor rebuild, you beating on it (not saying you do), oil/coolant feed problems, who knows. I'm not familiar with VNT's so I can't say to much with out being ignorant.
Overboost may be another problem completely. Was it overboosting prior to the high pitch? Could overboosting have caused damage resulting in poor performance? Cut out should be linked to MAP signal. Start checking vac lines in on the MAP system, maybe try another MAP.

89CSX#179 · 10-20-2005, 12:16 AM

Yes, the high pitch came with the poor performance as did the overboosting.

89CSX#179 · 10-20-2005, 09:33 PM

Ok, we checked my boost gauge to see if it was extremely off, it's really only 1psi off. We set my grainger to 13psi and installed it on the upper nipple on the VNT canister, this did nothing. My grandfather rode with me so he could see what exactly the car was doing, he says there is no way the turbine is rubbing the housing. Only thing we havent checked is the MAP, which we are going to get to this weekend.

OmniGuy123 · 10-20-2005, 09:38 PM

Quote:

Originally Posted by 89CSX#179

Ok, we checked my boost gauge to see if it was extremely off, it's really only 1psi off. We set my grainger to 13psi and installed it on the upper nipple on the VNT canister, this did nothing. My grandfather rode with me so he could see what exactly the car was doing, he says there is no way the turbine is rubbing the housing. Only thing we havent checked is the MAP, which we are going to get to this weekend.

If you have not physically checked the shaft play, how can you be so sure that the comp wheel is not contacting the housing?

89CSX#179 · 10-20-2005, 09:54 PM

well wouldn't that slow down spool time? It boosts faster than before

Turbo88 · 10-20-2005, 10:46 PM

If it wasn't the rubbing, and you said it was boosting like a mother but the power wasn't their you may need to upgrade your fuel system im not so sure is u did or not but my car was doin the samething i will have more power at 5-8psi but when it to like 9-12psi it felt like crap so i put an intake, fuel injectors, fuel pump, and regulator and my problem was done only thing is now my car has fuel cut off from over-boost but when i didn't have all those things and was goin at like 9-12psi it would surge
so just keep that in mind.

89CSX#179 · 10-21-2005, 10:36 AM

no, the fuel system is stock, with this in mind, we still dont know what is causing the overboost, which is the #1 problem right now.

89CSX#179 · 10-21-2005, 10:48 AM

I have noticed my MPG has gone south tho