Help with exhaust manifold

[yeti88]

Hey guys im desperate and have no idea what is going on, its about 12,30 and i deffinatly no mechanic. I cracked my old turbo manifold and just got my new 2g ported manifold today. I also got all new gaskets with it. I remembered to put them all in and i think they were all done right. but when i started the car up i could hear an obvius exhaust leak. I think it would be my o2 pipe (i dont know the exact name but i think thats what its called) that would have been the least tight bolts. But when i step on the gas a little i was not boosting .... it went to 0 then started to vacum to about 10 or so!?!?! I double checked all of the nuts and bolts from the manifold and to the turbo and they are all extremly tight... I didnt use the special bolts that are heat tempered i used regular bolts to secure the turbo down....I have no idea what could be wrong, anyone have any suggestions?

 

[toomey200]

Ok first of all were you moving? Because if you were just in neutral reving the motor you arent going to boost and the vaccum is totally normal.

 

[silver bullit]

Use torque wrench and torque specs on the bolts.

 

[yeti88]

i was in neutral but i just tryed moin it with the same results... i didnt hear my bov at all nor do i hear my turbo spool just the sound of an exhaust leak

 

[kenamond]

Also, make sure you reconnected the wastegate actuator arm to the little lever on the turbine housing. If you left that disconnected, the turbo wouldn't boost. This, of course, assumes that you disconnected that arm in the first place. Like toomey200 said, you won't boost unless the motor is under load (in gear, accelerating).

Also, I highly recommend getting the proper bolts and studs. You might be okay, but the correct ones are cheap (something like $4 each) and will do the job for sure. If you buy them all at once, you'll only have to pay one shipping charge. Getting new gaskets is cheap, too, so you could order the whole lot and save on shipping. I know that Extremepsi.com has all of those parts, because that's where I got mine.

 

[yeti88]

what are the torque specs for the turbo? and as for the wastegate.... the i have an tial wastegate what arms are there.... the owner before me seems to have welded the internal inplace of the aftermarket one?

 

[kenamond]

what are the torque specs for the turbo? and as for the wastegate.... the i have an tial wastegate what arms are there.... the owner before me seems to have welded the internal inplace of the aftermarket one?

Sorry, didn't read your profile. I'm not familiar with that wastegate, so I can't ponder possible problems. However it's actuated, though, if you haven't properly connected it, that might be related to your no-boost problem.

And if you have a bad exhaust leak, you need to pinpoint it. If it's downstream of the turbine, it won't cause a big problem, but if it's upwind, you'll lose backpressure which *will* affect performance.

 

[yeti88]

yeah i know i need to fix the leak but if it was at the manifold/turbo would i be able to feel it easily? and i dont think i realy could have hooked up the wastegate wrong it was just 2 bolts? and as long as the leak isnt the source of this problem i will have that further inspected tomarrow just want to get the "no boost" first.

 

[kenamond]

yeah i know i need to fix the leak but if it was at the manifold/turbo would i be able to feel it easily? and i dont think i realy could have hooked up the wastegate wrong it was just 2 bolts? and as long as the leak isnt the source of this problem i will have that further inspected tomarrow just want to get the "no boost" first.

Does the WG bolt to the ex. mani. or to the O2 housing (the elbow that connects the turbine housing to the downpipe)? If it bolts to the mani, did you have it on your old mani before it cracked?

 

[yeti88]

my old waste gate bolted up to the manifold the only diference is that the old one was on the left and the new one is on the right. and yes i had it on there before.

 

[kenamond]

my old waste gate bolted up to the manifold the only diference is that the old one was on the left and the new one is on the right. and yes i had it on there before.

Well, your WGA has to be connected somehow to your boost controller. This is usually a vaccuum line. This tells the WGA when to open up so that you limit your boost to the correct level (by diverting the exhaust so that it doesn't pass through and therefore drive your turbine as much). I don't know much about external WGs, so I can't really think of possible problems with it other than that. With internal WGs, if you forget to hook up that vaccuum line, you get the opposite problem from what you're seeing: you boost too much. But I don't know if it's different for your external WG.

 

[jumpfroggy]

Ok first of all were you moving? Because if you were just in neutral reving the motor you arent going to boost and the vaccum is totally normal.

Yeah. At idle, a car engine produces vacuum (it's pulling air into the engine, pulling = vacuum). I idle about -20inHg or so. When you rev the engine in neutral, you can get a little boost maybe, but not much. Usually it'll just go to 0.

0 psi = no pressure difference from atmosphere. So if you let off the gas, there's no pressure for the BOV to release since it's already equal.

You hear an exhaust leak. Can you tell yet where it's coming from? Try listening from different angles. You may also be able to feel it (though you'd probably scald your hand). What about holding something near that will detect the gas escaping, like a slip of paper.

So far it seems like a) you're idling with vacuum normally, b) in neutral, your boost builds normally, and c) you have some kind of exhaust leak. Is that about right? Also, a torque wrench is $30 at walmart. Granted, it's probably not very durable or accurate. But I'd take that over just guessing any day. Just think, if you didn't tighten enough you'll get small weird leaks that'll plague you, and if you overtighten then you might not be able to get the bolt out later. How much is it to remove a broken bolt or get yet another replacement manifold? Last, why skimp on the bolts?

 

[yeti88]

well what is the torque specs ?

 

[yeti88]

just so everyone knows....
thanks for helping and all of your suggestions, its amazing how much some oof you guys know just by a brief statement! I brought my car down to Victor Research (http://www.victorresearch.com/) a semi-local dsm shop, where i had gotten the manifold from. The guy helping me pointed out that i actualy did install everything correctly , and was confused by the obvius leak. After a few tense walks back and forth from the shop and the parking lot he came to the conclusin that it was actualy the water line (i think thats the pipe atleast) that sits behind the turbo. It was pushing on the turbo and prventing the bottum of the manifold from creating a full seal with the motor. My old tubular manifold i guess had either been further away from the motor or lower, thus not requiring any motifications to the line. So once again thanks for all the late night help guys i realy did appreciate it, and dont worry i had them order me the special bolts, while the line and turbo are modified to fit

 

[toomey200]

I dont know the torque specs but if you just make them tight it should be fine. Did you put your gasket back in between you turbo and manifold?

 

[yeti88]

yeah i did after taking everything aprat i noticed that the impression from the manifold was not as evident on the bottom .

 

[kenamond]

yeah i did after taking everything aprat i noticed that the impression from the manifold was not as evident on the bottom .

You should get a Haynes or Chilton manual. Also, the digitized CD tech manuals give a lot more info than that. I'm too lazy to go up to the garage to get my Haynes manual for the tech specs. You can read up on these CDs at www.manualcd.com, but they stopped selling them and defer you to ForcedPerformance who does sell them. Here's the link on the FP site.