No boosting problem

[gamingguru]

Ok, here is my problem. I have a PTE 52mm turbo and can't build any boost. I have replaced all of the stock IC piped with hard ones. I haven't run a boost test yet but I plan on doing that over the weekend. When I put on my 3in exhaust I couldn't get one of the bolts on. I have done some nice bolt maneuvering but this one was just too tight of a fit for me. I also have an external wastegate. How possible do you all think it is that my boosting problem is being caused by the exhaust gas leaking and not some other source. The most boost I have had during the past few months is only like 2psi, any input would be appreciated. Thanks.

 

[oldman]

1. Exhaust leak after turbo will not affect the boost level.

2.

I haven't run a boost test yet

Very important that you do one before your next WOT.

3. I'm not familiar with external wastegate but sounds like it might be stuck open.

Good luck.

 

[gamingguru]

Are you for sure that a exhaust leak right after the turbo will not effect the boost build up? It seem to me like it would, considering that an external watesgate is placed after the turbo. I do not really thing that my wastegate is stuck open although it might be. You can feel exhaust gassed passing out of it when the car is idling. But I installed it like I thought it should be and I ran a vac line from the outlet on the turbo to the lower side of the wastegate. I know that DSMJim has a 38mm tial gate... If you could let me know if your gate is partially open when you are idling. I don't make it a habit of romping on it, but I really need to get things straightened out before I hit the dyno and do some tuning with the EMS.

 

[oldman]

Are you for sure that a exhaust leak right after the turbo will not effect the boost build up? It seem to me like it would, considering that an external watesgate is placed after the turbo. I do not really thing that my wastegate is stuck open although it might be. You can feel exhaust gassed passing out of it when the car is idling. But I installed it like I thought it should be and I ran a vac line from the outlet on the turbo to the lower side of the wastegate. I know that DSMJim has a 38mm tial gate... If you could let me know if your gate is partially open when you are idling. I don't make it a habit of romping on it, but I really need to get things straightened out before I hit the dyno and do some tuning with the EMS.

Exhaust leak was referring to your 3" exhaust fitment problem hence after turbo. O2 mounted external wastgate is not after the turbo, it's part of the turbo hence #3.

 

[gamingguru]

I discovered yesterday that my wastegate was hanging my a bolt and that half of the metal gasket was missing. This is most likely due to the steal flexing I thought. Do any of you know if that high temp RTV silicone would be able to withstand exhaust gas temps without melting?

 

[oldman]

I discovered yesterday that my wastegate was hanging my a bolt and that half of the metal gasket was missing. This is most likely due to the steal flexing I thought. Do any of you know if that high temp RTV silicone would be able to withstand exhaust gas temps without melting?

Use copper RTV which is rated at higher temperature than red.

 

[99gst_racer]

Use copper RTV which is rated at higher temperature than red.

Yeah, but even the copper stuff cant handle the heat. It'll burn off the first time you go WOT. Replace it with a new gasket.....

 

[oldman]

Yeah, but even the copper stuff cant handle the heat. It'll burn off the first time you go WOT. Replace it with a new gasket.....

I was under the impression he was going to use it with a new gasket.

 

[gamingguru]

Bring back my old thread.

I have replaced the seals on my throtle body no after running a boost leak test. The test showed that air was leaking out of the throttle body area. But, I stil can't make more than 1 psi of boost. I have order the other seals that are on the throttle body but it seem to me that they are unlikely to fix my problem. All of me intercooler piping and none of it is leaking any air, neither is the intercooler. The BOV flange is fine as well. I think that I might get a MBC and try and try and use that to see if I can make any more boost that way. I really don't like that idea though because my wastegate spring is a 14.5 psi one. Any ideas will be appreciated because I am running out of options on getting my boost back. What could be left?

 

[oldman]

Let's focus on the leak test, sounds like you're having trouble with it.

1. If you're using a bike pump, get yourself a cheap air compressor.

2. Disable the stock bcs, it controls boost by bleeding off air so you could be loosing a lot of air through it.

3. Open the oil cap and listen for air leaking into the crank case. If you hear leaks in the crank case, follow this thread. http://www.dsmtuners.com/forums/showthread.php?t=174682&page=1&pp=25

All of me intercooler piping and none of it is leaking any air, neither is the intercooler. The BOV flange is fine as well.

You can't possibly know that right now because you're only able to build 1 psi so far, different leaks develops at different psi level. Be patient with the leak test, most of the time it's a long process. Fix whatever you find first and repeat process until the system is able to hold 20psi for about 30 sec. After you complete the leak test and fix all leaks you find, we can then troubleshoot the turbo with a greater confidence. Post back.

 

[gamingguru]

I have an air compressor. To test for leaks I set it to push 35psi and then connected it to the turbo inlet. Looking at my boost guage I was pressurizing the system to about 13.5 psi.
I don't have the BCS hooked up. I am running a hose straight from the turbo compressor housing to my wastegate. I will check for air leaking into the crank case sometime next week. When I replaced the gaskets on my throttle body I looked everything over and it appeared to be fine but when my car is idling you can hear air hissing out from the throttle body area still. Could it be the ISC motor leaking boost out of the bottom of the throttle body possibly? Here is another though, since I can pressurize the intake side of my engine to 13.5 psi with my air compressor but can't build but 1 psi when the car is actually up and running might this be a wastegate issue. How possible is it that not building up enough back pressure in the exhaust system would case me to be unable to build any boost pressure? I am asking this because I have a 3in exhaust and a tial 38mm mounted of of my O2 sensor manifold, different from the usuall internal gates that most people seem to run on this board.

O ya, I pressure tested my intercooler when I was puttin on my new pipes and you couldn't hear any air hissing out of it at about 19 psi of pressure. and when testing for leaks no hissing sounds were heard from any of the intercooler piping coupler locations.

Thx for the help. I hope to get resolved soon so I can do some tuning with the EMS.

 

[oldman]

I thought you meant you were only able to build 1psi during pressure test. The leaking at the TB could either be BISS o-ring or the shaft seals, check vfaq under intake/tb. 13.5 psi is not bad but there are probably more leaks to be found so completely the leak test.

It's very possible that your external wastegate is either stuck open or opens prematurely. Is it adjustable? If so, try tightening it up first. If not, see if you can borrow a known good one and test. If problem persists after that, it's pretty clear the turbo is the issue. Have you check it yet for for shaft play? spinning freely?

 

[gamingguru]

My turbo spin as freely as it did when I got it. I have only put around 3-4k on it so it is fairly new. It does have a slight amount of back and forth shaft play, but it seems to be withing reasonable limits. I will try and get my hands on a MBC to keep the wastegate closed longer. I know that the valve is not stuck open on the thing though( I just looked). I am hoping that it's not the turbo, I have been though 3 of them since I got my car. I will also be ordering the o-rings for the TB this week I guess.

 

[oldman]

I will try and get my hands on a MBC to keep the wastegate closed longer

It would be a good thing to have but for now you can do a simple test. Remove the hose between the turbo and wastgate and test run. If boost shoots straight up, don't forget to let off the throttle, then the wastegate is opening prmaturely and getting a mbc will help though you might want to change it anyway. If problem persists, the wastegate is being blown open by the exhaust flow and getting a mbc isn't going to help you there.

I am hoping that it's not the turbo, I have been though 3 of them since I got my car.

That troubles me. Did you ever find out what the cause was? Did they all die the same way? Let's hope you're not going down the same route.
Have you done a compression test yet? If not, it wouldn't hurt to do one.

 

[gamingguru]

Here are the turbos I have been through:

1. T-25 at 130k miles, the seals when't bad and let oil run all through everything
2. used T-25 with no shaft play died after about 100 from compressor surge, my BOV was not opening and sadly the inpeller shaft of the turbo was literally snapped in half.
3. Well, I guess that I have only really been through two turbos, I am on my third one. I am going to test my wastegate like you suggested tonight. I'll post back on the results latter.

 

[Maglin]

My turbo spin as freely as it did when I got it. I have only put around 3-4k on it so it is fairly new. It does have a slight amount of back and forth shaft play, but it seems to be withing reasonable limits.

Well if you have back and forth shaft play that you can actually see it's a good bet that your turbo is shoot. And for the limits you would need to see the makers suggested tolerances. Axial play on say the Holset HX-35 is only .001-.005 in. That isn't really even all that noticeable visually. Even if your WG is opening prematurely you should still see some boost. Only times I've seen turbo's not build boost past 1-3 psi is from bearing failure. Some of the didn't have enough shaft play for the wheels to touch the housings and most all of them spun very freely. I had a B16G that just recently did the same thing. Pulled it and slapped the 14b on their and I went to 20 psi in a heartbeat.

You said that you have never seen boost with this turbo since you purchased it? If you got it from a vendor then I would strongly suggest you call them and have to replace it. Getting a bad turbo that is new isn't a very good sign a lot of times. But faulty parts do happen to make it to even the most reputable vendors.

 

[gamingguru]

Hum... faulty turbo. That is a possibility I guess. Do any of you have an idea on what kind of waranty a PTE trubo would have on it? O Yea, with the wastegate hose off I still didn't build any boost. Just to gather myself, the remaining possiblities for my boost problem are:

1. Valve seals
2. Exhaust not having enough backpressure in it.
3. Turbo Failure

It just came to my mind that maby I installed my wastegate wrong. Just so I can be sure install is not the problem here this is what I did. I took my 3in O2 eliminator downpipe that was made without the flange for an external gate already mounted on it to the welding shop and had then weld my tial flange onto the part of the tublear O2 housing that comes off of the hole in the hot side of the tubo without the wheel in it (Can't think of a name for it right now). And then I put it back on my car. From what I understand this is alright, but if someoune could second that I would appreciate it. I think that I will give the store I got my turbo from a call and see what they can do for me. I would really hate to have and run without a turbo though because the car is to stinking loud dumping straight from the manifold. O well, what can you do.

 

[oldman]

It's either wastegate or turbo. I agree with maglin it's probably the turbo. The question is why? Double check your oil feed and return, must find the reason or you'll be swapping turbos often.

 

[gamingguru]

Well, My oil return is 10AN down to the oil pan, and the feed is 4AN from the oil filter housing like everone and their cousins dog told me to run when I was putting this new setup together. I change my oil every thousand miles or so, so I don't think that my turbo bearing could have gotten debree in them. Maby I really did just get a bad turbo. If that is the case I really hope that it won't cost me much to get it repaired, seeing as im not exactly running high on cash at the moment.

 

[Maglin]

When you installed the wastegate to the O2 eliminator did you also seal off the hole that went from the Wastegate opening to the exhaust? Or did you run the pipe out of wastegate opeing to the external and fromt he external to the O2? Or did you just weld the wastegate to a flange welded onto the O2 eliminator? Cause the latter would be wrong and it would bypass the wastegate all the time. But even if that is the case you should still see some boost from creep. Even with an external wastegate and haveing the external not even installed you would be seeing some boost be it very low but you would see it.

 

[99gst_racer]

2. Exhaust not having enough backpressure in it.

Dont worry about backpressure. The turbocharger itself creates more than enough backpressure for the engine to effectivily opperate.

 

[talongod]

i had an exhaust leak right after my turbo and i coulnt build boost so that might be ur problem

 

[Patterson]

i had an exhaust leak right after my turbo and i coulnt build boost so that might be ur problem

Sounds like the wastegate is stuck open. If there was a leak, you would at least build some boost. Otherwise, your car would be undrivable. keep us posted. happy hunting.

 

[gamingguru]

Just so you guys know, it was the exhaust leak that was causing my problem, I switched to a stock 2g O2 housing so that I could get all the bolts in for a little bit and that fixed the problem. And to whoever said that the car would not be drivable I hope that you mean it would be no fun to drive. I am running off a MAP sensor and have an EMS. I can drive the thing pretty much no matter what. Anyway, I just got it tuned up deacently, ~12AFR while under boost and 15-17 dergrees of times when the next day I was rolling down the highway and punched it only to break the darn car again. Spun a rod bearing. I guess its time for a new motor now. That 50 trim really did pull a lot harder than my T-25 ever did though. Can't wait to try it out on my new motor after I get it in.

 

[talongod]

ya i new it i had the same problem