Turbo spooling trouble...

[oldman]

It will let a large amount of un-metered air into the system and cause you to run pig rich

That would make it lean, not rich.

 

[daren_p]

The engine vent hose popping off of the intake will cause the problems you are describing. It will let a large amount of un-metered air into the system and cause you to run pig rich, as it connects to the intake after the mas.

I must be missing something, how do you think this is causing his issue? & allowing unmetered air into the system would make it run lean, its when you vent metered air that it runs rich. He'll have to check to see if his intake actually has a barb for this line, as it may not but if it does have a barb that is now open that would be a source for losing metered air. As for a large amount of unmetered air entering the system because the crank case vent isn't connected, sure when he's at idle & seeing vacuum the PCV valve opens up pulling the air from the crank case and yes he will be allowing unmetered air to enter the system in this condition. But his problems is when he's in boost & at higher levels. When there's pressure in the intake the PCV valve closes & unmetered air is no longer entered into the system. We all know its not good to leave this hose open as the vacuum created by the turbo helps to clean out the crank case when connected properly to the intake.

 

[B-lackGSX99]

I took a look at that hose that runs off of the middle left edge of the valve cover...the one that should be hooked up to the intake. Is that the "engine vent hose" that you guys are talking about?? I can't figure out where it is supposed to connect to the intake though. Should I take some pictures from any particular angle?? I have had this hose not connected to the intake at all since I have had the car, although I understand that this doesn't mean it is safe, I just wanted to mention it in case that information is of significance to what is happening right now. Thanks for the help!

 

[kmoore]

Well actually depending on the size of the boost leak it can actually do some damage, that is if your doing WOT pulls. Under normal driving you should be fine but if your trying to make full boost & your leaking that pressurized air out, the turbo is working much harder to try & produce the required boost. While this isn't so bad with larger turbo's, the T25 is tiny to start with & can barely keep up with even a small amount of boost increase. Now add ontop of that your now making the turbo work even harder. If this is done regularly you will defently shorten the turbos life, not to mention you may also be causing additional engine knock as the inlet charge is now going to be much hotter.

On a side note, I too would also say this sounds like a boost leak issue.

Absolutely, in NO way should you push the car hard at all. I completely agree with you 100%. But, like I said, if its your daily driver and you HAVE to get somewhere, it won't kill the car. Just not run at its optimal performance

B-lackGSX99- on your intake pipe you should have nipples (don't laugh) that jart out about an inch from your intake pipe that are spread out from each other (you can have as many as 3 or, in your case, none). That hose that comes off of your valve cover should be plugged into one of these nipples. The charcoal canister hose (hose that comes from underneath your passanger side) should also be plugged into one of these tubes. If you are worried about emissions, you should plug the charcoal canister hose it into one of these nipples. If not, then you can just let it hang. But, for your valve cover hose you should plug that back into your intake. Or you can buy a catch can. I have heard of people drilling an tapping/JBwelding nipples back onto there intake, for such hoses, which ever works best for you.

 

[daren_p]

I took a look at that hose that runs off of the middle left edge of the valve cover...the one that should be hooked up to the intake. Is that the "engine vent hose" that you guys are talking about?? I can't figure out where it is supposed to connect to the intake though. Should I take some pictures from any particular angle?? I have had this hose not connected to the intake at all since I have had the car, although I understand that this doesn't mean it is safe, I just wanted to mention it in case that information is of significance to what is happening right now. Thanks for the help!

Did you order the intake or was it already on the car? It could very well be you don't have all the nipples reguired depending on how the intake was ordered, as dejontool will make it with no nipples, all 3 stock nipples or whatever combo you request. This hose on the valve cover your refering to is the hose for the crankcase vent & like I explained above this shouldn't be causing your issue but its not the best to have it just sitting there not connected either. Usually the nipples are on the back of the intake (BCS one on the front) so check there to see if you have them. If you don't, I personally would drill & tapp the intake so I could attach a barbed fitting to connect the required hoses or you could always take it somewhere to get some nipples welded on.

 

[B-lackGSX99]

The dejon intake came with only one nipple...would it be a smarter decision to run the loose one into the intake instead of the one running to the charcoal canister?? I'm not worried about emissions, Edmonton/Alberta could care less.

Got a new problem...went to Napa, Partsource, 2 plumbing stores...found a four inch piece of hose that I can use as the boost leak tester, as well as a nice valve stem. BUT, nowhere I went to carries an end piece that will fit over the 3 inch inside diameter hose. 3 inch diameter hose, I say?? Yep, my turbo inlet is 3 inches in diameter. I'm gonna search long and hard for the necessary pieces to complete the boost leak tester, but there's my current scenario...pretty comical, in a sadistic sort of way. Again, thanks for the help!

 

[kmoore]

What I did was went to Home Depot and found a rubber coupler (comes in a different sizes) and also a PVC pipe end that fits inside that rubber coupler. Now, Home Depot (atleast the last time I checked) did NOT have a Shader (sp?) air valve, so I had to go to ACE hardware for that.

And the one nipple that you have is on which side of the intake? Front or back? I would say since you have a MBC, and are not concerned about emissions, use that nipple for the hose coming off the valve cover.

 

[B-lackGSX99]

Home depot also disappointed me...the biggest hose coupling they had was in 1.5 inch diameter, and the biggest end cap they have is 2 inches...

Yes, the hose that is currently hooked up goes off of the back (pointed towards the passenger seat) of the intake. I'll see if I can switch it for the hose that is running off of the valve cover.

Random question, I am beginning to become unsure of what turbo was put in the car (this was done previous to my ownership). It does have a mitsu emblem on it, and reads (immediately after the emblem on the compressor housing) 49179...on the bottom part of the turbo (the part leading towards the intercooler, it reads 40114. Is there any other information that I can get for you guys in order to determine what turbo this is?? I always thought it was just a regular 20g...but i'm thinking it might be a bastard. On a side note, what's up with it having a 3 inch diameter inlet? ...thanks!

 

[B-lackGSX99]

Okay, so i've been thinking a lot about this whole thing. I think i've located a place that will carry the right sized hose and end cap, so i'll grab that as well as a 2.5 diameter set-up too (i'm positive that this is the size of my upper intercooler piping).

T'row afternoon, i'll be swinging the car by a Subaru dealership that my roommate manages. He tells me his service guy says he "knows all there is to know about turbo talons/eclipses". Yeah, I know . Anyways, he wants to throw it up on a hoist, rev it gently yet hard enough to build a little boost, and listen underneath with a stethoscope in order to locate the leak. At this point in time, i'm willing to try anything, I won't be able to swing out to get the rest of the boost leak tester parts until afterwards anyways.

So, what i'm wondering is if this is okay to do to the car...i've searched the forum but can't find whether or not it is okay to run the car on a hoist like that. I'm a bit worried about the viscous coupler burning out because the car is being run with all four wheels "slipping". Any suggestions, or warnings?? As always, your help is much appreciated.

 

[Rob10_99]

Just to elaborate on the boost leak rich/lean thing,


if you have a leak after the turbo,
non boost- lean
on boost- rich

before the turbo, after the maf
non boost- lean
on boost - lean


ISNT THAT CORRECT>?



before this gets locked for being another "xor BLT champions of the world" thread

 

[dsm-onster]

Just to elaborate on the boost leak rich/lean thing,


if you have a leak after the turbo,
non boost- lean
on boost- rich

before the turbo, after the maf
non boost- lean
on boost - lean


ISNT THAT CORRECT>?



before this gets locked for being another "xor BLT champions of the world" thread

Yes, you got it.

T'row afternoon, i'll be swinging the car by a Subaru dealership that my roommate manages. He tells me his service guy says he "knows all there is to know about turbo talons/eclipses". Yeah, I know .Anyways, he wants to throw it up on a hoist, rev it gently yet hard enough to build a little boost, and listen underneath with a stethoscope in order to locate the leak.

Hmmm, I remember having to rev to kingdom come to get my small 16g to spool enough in neutral. I'm sure he knows what he's doing. . . Subaru guys usually know alot about mitsus. They're competition. But, I don't know about the revving her up to detect a boost leak. Seams like a waste of gas and I like to save my rpms for good use. Patience is a virtue. But, I may be b!tchy about my car, too.

 

[tkelly27]

You can't rev a car gently in neutral to build boost. I doubt you'd be able to hear the boost leak over the engine. If he's going to have you put it in drive and do a brake stand on the hoist, run far far away. As a subie shop they should have a boost leak tester. As a DSM owner, you should finish yours.

 

[B-lackGSX99]

Yes, i'm very curious to see how this guy goes about testing for a boost leak up on a hoist. My car is a 5-speed, so a brake stand is out of the question either way. Can you even get a car into gear without the tires being on the ground?? If so, i'd only need to get it up to around 2400rpm before you begin to hear the odd turbo spooling sound...but you're right, I can't imagine how he's gonna hear anything over the sound of the engine/exhaust (keeping in mind, it's pretty well 3 inch diameter piping front to back...BWAAARRRRRRR, it's loud). I hope he doesn't go deaf, holding the stethoscope up to things, hahahaha.

If any of you are wondering how this is all going to go down, i'll report back when I get back from Subaru and the store where i'm gonna hopefully grab the remainder of the boost leak tester stuff.

 

[daren_p]

His testing method sounds completely redicules to me, it will be interesting to see what he can find. Without a load on the car 2400 rpms isn't going to spool the turbo. With my evoIII turbo I could build around 5 psi boost with the studderbox set at 4500, but you are also holding the pedal to the floor while doing this. If you just hold the gas down to say 3000 rpms without any load on the car (which there won't be), I doubt you will see more then a couple psi boost, if you even see that. I have no idea how he thinks he will hear anything with a stethoscope with all the other noises that will be produced. Checking for a bad bearing or something with this method is one thing but trying to find an air leak?

 

[oldman]

Yes, i'm very curious to see how this guy goes about testing for a boost leak up on a hoist. My car is a 5-speed, so a brake stand is out of the question either way. Can you even get a car into gear without the tires being on the ground?? If so, i'd only need to get it up to around 2400rpm before you begin to hear the odd turbo spooling sound...but you're right, I can't imagine how he's gonna hear anything over the sound of the engine/exhaust (keeping in mind, it's pretty well 3 inch diameter piping front to back...BWAAARRRRRRR, it's loud). I hope he doesn't go deaf, holding the stethoscope up to things, hahahaha.

If any of you are wondering how this is all going to go down, i'll report back when I get back from Subaru and the store where i'm gonna hopefully grab the remainder of the boost leak tester stuff.

Don't waste your time, it won't work.

 

[B-lackGSX99]

Okay, so the guy at subaru had me start off just by popping the hood (car not on hoist) and firing up the engine. With the car at idle, and stethoscope in ears (the bottom disc piece that usually goes on your chest removed so it was just a hose) he commented right off the bat that it sounds like I have an exhaust leak. He then put the hose end up underneath the exhaust manifold cover and said he could definitely hear air coming out. I took the stethoscope and listened in this area and could hear air also. So his recommendation is to get the car into a specialist to remove the turbo and exhaust manifold. Have this specialist send these parts to a machinist to polish down the connecting surfaces, and reseal it all with high temp sealant. He also suggested not driving it in the meantime, for fear of destroying/warping anything due to the high heat that was coming out of the exhaust manifold.

By no means does this mean that i'm not going to listen to you guys though. I'm still gonna build a boost leak tester for use (I was able to locate the remaining parts so that I could build one for a3 inch diameter turbo inlet). It's not a pcv end cap, but it should do...will post up a pic once it's built, see what you guys think.

My question now, is whether or not you guys feel that the Subaru guy is making sense. Comments, or suggestions?? I've done a bunch of searches on exhaust manifold leaks...i'll pop the exhaust mani. cover and inspect the inside, will continue this thread, but in the appropriate place as I don't see it belonging in the turbo tech section. Thank you all for your help, it has meant the world to me!

 

[B-lackGSX99]

Here's what i'm using for my 3 inch intercooler lead tester...just gotta get a different set of band clamps, forgot to account for the thickness of the hose!

 

[romeen]

Okay, so the guy at subaru had me start off just by popping the hood (car not on hoist) and firing up the engine. With the car at idle, and stethoscope in ears (the bottom disc piece that usually goes on your chest removed so it was just a hose) he commented right off the bat that it sounds like I have an exhaust leak. He then put the hose end up underneath the exhaust manifold cover and said he could definitely hear air coming out. I took the stethoscope and listened in this area and could hear air also. So his recommendation is to get the car into a specialist to remove the turbo and exhaust manifold. Have this specialist send these parts to a machinist to polish down the connecting surfaces, and reseal it all with high temp sealant. He also suggested not driving it in the meantime, for fear of destroying/warping anything due to the high heat that was coming out of the exhaust manifold.

By no means does this mean that i'm not going to listen to you guys though. I'm still gonna build a boost leak tester for use (I was able to locate the remaining parts so that I could build one for a3 inch diameter turbo inlet). It's not a pcv end cap, but it should do...will post up a pic once it's built, see what you guys think.

My question now, is whether or not you guys feel that the Subaru guy is making sense. Comments, or suggestions??

If the leak is big enough where escaping heat could affect surrounding components then you probably would not need any special equipment to locate it. He may be correct about having an exhaust leak but his recommendation to have the flanges resurfaced seems overly aggressive in dealing with the issue. First check that all fasteners are torqued to spec. Then try running a 1/2 can of Seafoam through your intake. The resulting smoke will find its way past even the smallest exhaust leak. If you do have leaks then you will probably have to remove the component in question and examine for obvious warping. Usually just replacing the gasket will be sufficient. I have heard mixed results with using copper RTV but it may be worth a shot. It wont harm anything.

If you are concerned about warping you can always check with a straight edge and feeler guage. RRE sells a 4 layer exhaust manifold gasket (I believe it's stock on EVOs) which is supposed to seal better than the 2 layer gasket. I am using one and it works well.

 

[dsm-onster]

Looks like you found your trouble. A leaky exhaust mani gasket will cause very slow spool and all sorts of strange noises .

Don't bother w/ the "you'll need a specialist" think just yet. What specialist is needed to replace a gasket ? I must be a frickin' SUPER specialist. I wear a white coat when I work on my DSM!

Heres the internet specialist.

I know 500 people that can pull the turbo and exhaust manifold off my DSM. . . including YOU! I rooting for you man!

Here's where you go to get help if you need: this forum and Turbo swap on a 90 AWD. The latter is focused on a 1G engine bay. However, the differences are very minor. Primarily theses differences consist of oil feed like origination and lower intercooler piping differences.

Don't sweat the tweaked exhaust mani surface thing just yet. Take her apart an FIND OUT if it is warped. In all likelyhood your specialist won't even check the straightness and just order a machining anyway; telling you, 'better safe than sorry. . .'

 

[daren_p]

Whats posted above is some good info, I wouldn't go calling in the "specialist" just yet. Take the mani cover off & see if you can locate the source of the leaks. Like Romeen said, if your not able to locate them, running seafoam will defently help you in spotting them. There are a couple reasons why our exhaust manis can leak & a warped mani isn't usually one of them. Areas to check would be a bad head to mani gasket, bad turbo to mani gasket, the bolts/studs being lose in either of those mentioned areas or the mani itself may have cracks. All of these are pretty simple fixes & like Matt said the vfaq is defently your friend. You'll be able to find pretty much every "how to" you'll ever need.

As for the parts for your boost leak tester, it looks like the piece you are going to attach the coupler to is threaded along the whole outside body? If so you may have trouble trying to get it to seal. One other note when your assemblying the tester, make sure to get the clamp on the end good & tight. The end fittings usually don't have something that acts like an IC pipe bead so it takes alot more clamp pressure to get the coupler to stay on. First time you blow out the tester end at 20 psi, you'll understand why I say this

 

[eclipsegsx1736]

Check torque on manifold-to-head nuts and turbo-to-manifold bolts as mentioned above. They can back out after some heat cycles especially if you got the turbo pretty hot. Same exact thing happened to me (slow spool, wouldn't boost past ~21 psi, accompanied by a loud air noise) and it took about 5 minutes of torquing the bolts again and it was fixed.

 

[tkelly27]

No wonder everything costs so much at a stealership, you've gotta call in a specialist when a gasket starts to leak!

Seriously, retorque the bolts, if it doesn't go away (you've gotta have a hell of an exhaust leak to keep your turbo from spooling, think how big the WG is!!), pop the manifold off, if you are paranoid have it checked at a machine shop, if you're a normal human, replace the gasket and go.

The parts for that boost leak tester looks like they cost more than my whole car... $25 for the silicone, $6 for the T bolts, $3 for the loctite... yeah almost!! Nice dude.

First time you blow out the tester end at 20 psi, you'll understand why I say this

Kuh-blamo! I always wear eye protection when using mine. It's PVC pipe with pipe cement. Eek!

 

[dsm-onster]

Yea Mine wouldn't hold over 25 psi even w/ a t-bolt clamp!. But spray a little hair spray on the end and fit the coupler on and she holds to 35 psi.

I have a pvc unit w/ pipe cement. However, I'm using a mail threaded quick disconnect fitting for air comperssor tools. It makes runniing a leak fst and hands free. I can step away from the engine bay and slowly bring up the psi w/ the compressor regulator.

 

[B-lackGSX99]

Okay, so I popped off the exhaust manifold cover, and felt around for the leak...it is basically as indicated in the pictures below. I wanted to start a new thread in "Bolt-on Tech" but won't quite yet because you guys have really helped alot with your last few replies. I've printed off the document detailing "Turbo Swap for a 90 awd". I've also bought an adjustable torque wrench good for 5 ft-lbs to 80 ft-lbs. I'll go about tightening everything up to spec t'row, but am wondering if anyone can tell me exactly which ones I should pay the closest attention to in order to tighten up the area shown in the pictures.

Lastly, in case I wasn't able to actually/accurately feel out the location of the leak, I did buy a bottle of seafoam. I'll give that a shot too if it turns out to still be necessary after I tighten up the known areas. To do this, do I pour it right down my air intake after the mas?? If so, i'll dump it down the tube that connects to my intake after the BOV. Your help is much appreciated!

 

[romeen]

DO NOT POUR SEAFOAM INTO YOUR INTAKE PIPE! You need to use a vacuum hose connected to your intake manifold to suck it out a little bit at a time. The easiest way is to use the vacuum hose that connects to the BOV.

1) Get car up to operating temperature
2) Have car idling
3) Remove vacuum line from BOV. Since you now have a large vacuum leak the motor will idle rough as if it is going to die
4) Stick the end of the hose into the can of Seafoam so that the vacuum is sucking it up. Don not allow it to suck up the whole can in one shot. Do maybe 1/5 can at a time or just until the motor wants to shut down. You may need a helper to give it some gas while you are doing this to keep the motor going. If you have exhaust leaks the smoke will start revealing them right away.
5) In order to hit the IM more evenly you may want to do some through the hose that connects to the PCV valve as well. It is too short to extend down into the can so you may need to temporarily replace it with a longer vacuum hose for the treatment. But since your main goal is to identify exhaust leaks as opposed to cleaning out your IM this is not a necessity.
6) After about half the can has been sucked up allow the motor to suck up enough so that it stalls
7) Let it sit for about 10-15 minutes. Even while it is sitting some smoke will continue to develop and work its way through the exhaust so that you can continue to identify leaks.
8) Make sure all vacuum hoses are hooked up. Start her up and take it for a spirited drive. You need to open it up a little to allow the residual chemical to burn off.

BE WARNED. Your exhaust is going to smoke like crazy. You may want to do this when it is getting dark so that your neighbors don't freak out. Try to stay on backroads with little traffic if possible. You'll see what I mean about the smoke. Don't worry, it's normal and expected and will burn off.

Make sure you do this in a well ventilated area! Don't even think about doing it in your garage!

If you have an old set of plugs sitting around you may want to put them in for the treatment and then reinstall the good ones after your all done.

Be careful about over tightening the nuts on the exhaust manifold studs. It's not too hard to strip the holes in the cylinder head. I stripped one while torquing it to specs.

You've already discovered that you are missing an exhaust manifold stud (I think it's the stud and not just the nut that is gone). When looking for a replacement make sure you specify which location it is for since that one is bigger than some of the other ones. I believe it is M10 x 1.25, not sure about the length but if you get an oem replacement you will be ok.

Make sure that there are TWO washers under the bolt head of each turbo-manifold bolt, otherwise they will be prone to backing out.