MrDomino

1998 Acura Integra LS with T3/T4 turbo, log manifold

A few days ago I noticed that my car was much louder than it had been for the past few months. It's definitely an exhaust leak somewhere. The thing is, I can still hold around 7psi of pressure which makes me think that it's occurring after the turbo. However, I'm really not sure how to start looking for it. If the leak is underneath the car then I can't really rev it and be underneath the car at the same time.

Do you think it's worth taking to a muffler shop and letting them check for it?

I guess I'm not sure what techniques can be used to find an exhaust leak. I know for a leak in the intake system you can pressurize it and then listen for an air leak but I'm not really sure how to track down exhaust leaks.

accord_raffi

Do this when the car is cold.
Have a friend cover the muffler tip while you are under the car listening for a hissing or feeling for a leak around the exhaust pipe.

NonovUrbizniz

^ That's not the best thing to do with a turbo car... you don't want to create enough back pressure to lock up the exhaust turbine.

Have you tried just looking yet? run your hand over the (obviously not touching it) and feel for a leak if you can't hear/see it... also look for any sooty spots at the welds or joints... those are the most likely spots.

Also you say "it can still hold 7psi"... if the exhaust gas leak is after the turbo then it will not affect the amount of boost you can hold... lots of people run open DP ie... no exhaust.

If you're loosing boost from an exhaust leak it's pre-turbo.

MrDomino

Yeah from what it sounds like it's coming from the front of the car but I can still hold 7-8psi. If it was pre-turbo, how much of a drop in pressure would I see? A few psi or would I not be able to hold any pressure?

I'm actually thinking it may be where the downpipe connects to the turbo although that's just speculation based on the fact that I hear the sound at the front and I can still hold boost pressure.

The engine seems to be running rougher too. Is that another problem or just a cause of the leak?

NonovUrbizniz

There's not set PSI you'll lose from a leak... depends on the severity of the leak. it's DEFINATELY pre turbo though if it's loosing pressure.

NOT DP or exhaust.

MrDomino

I'll have to go out later and make sure that it's still holding the same psi as before. It's kind of loud so I don't think it's a minor leak that wouldn't show up as a loss of pressure if it was in fact a pre-turbo leak.

MrDomino

Yeah, I'm probably not going to do that. However, I am curious about what you're talking about. How does the back pressure lock up the turbine? I'm guessing at idle you'd gradually build up back pressure on one side of the turbine and the pressure from the exhaust on the other side. This would essentially lock the up turbine. Does that make sense? What happens at that point? Things break I'm guessing?

MrDomino

One of my friends suggested sea foam. I've actually seen this suggested by a few other people too. I feel kind of nervous about dumping liquid into the compressor and then into the engine.

The video on it says to dump 1/3 of a can into the intake (slowly). Then dump enough in the intake to stall the engine. Then dump 1/3 of a can into the oil and the rest into the gas.

How do you guys feel about this?

96 GSR-T

Its as simple as letting the engine run, getting under the car and feeling for air, its not like you have 1/8 mile of exhaust piping to check, you should be able to pinpoint the leak rather quickly, do it with the car cold so you dont burn yourself.

MrDomino

I'm doing this tomorrow. If I don't find it this way then I'd move onto sea foam (I may sea foam it anyways). Just kind of asking so if I do decide to sea foam I don't accidentally blow up my engine.

NonovUrbizniz

They won't neccisarially break but it's definately not a good idea to do this test on a turbo car. You can stall a NA car by plugging the exhaust... so it would definatly mean force fighting both ways against your exhaust turbine... IE backpressure trying to spin it backwards and combustion chamber exhaust trying to spin it forward.

As far as the seafoam I'd recomend feeding it through the throttle body with the charge pipes disconected and the WG open (or boost cut set to zero) Even without doing that you should be ok as long as you don't rev it too high...

I wouldn't feed the seafoam through the turbo inlet though... it's too long of a path to go and your sending liquid through a compressor which is never a good idea.

But frankly I think you're overthinking the problem... chances are you're going to pop the hood see/hear an obvious leak and know what to do from there.

NonovUrbizniz

What I'm talking about is excessive back pressure being used to test for an exhaust leak... it's a dumb idea on a turbo car... Chances are he's going to open up the hood and find the leak in 2 seconds...

Secondly the OP doesn't even know what PSI he's supposed to be running so I wouldn't recomend doing a test on the car that is essentiall a ghetto trick and NOT good for turbo cars.

I've seen the reversion caused by this test blow out a exhaust manifold gasket on a STOCK NA car... so I definately wouldn't recomend doing it to a exhaust turbine. Rapid deceleration is the number one cause of damage to turbos... NO at idle it's not spinning hard but ANY reverse pressure is not good for the turbine.

It's pointless to recomend doing this test until he pops his hood and actually looks/listens/feels for the leak first. Chances are it's pissing out of the manifold and will be very obvious.

MrDomino

Yeah, I have to admit that I haven't had much of a chance to track down the leak as I just really noticed that it was an exhaust leak the other day. I changed the oil today and checked the downpipe and cat just to make sure they were fine and no major problems there from what I saw. Tomorrow I have some time in the evening I can play around with it and see if I can figure it out.

accord_raffi

Have you noticed any "odd" way the car has been building boost compared to before you heard the exhaust get louder? If it's much louder it might be your wastegate opening before it should.
Nonov, thanks for pointing that out on my first post. BTW, I asked you a question in another thread about compression leaking into the coolant system due to a bad HG. Can you get back to me on that. either in the thread or PM. don't mean to thread jack.

MrDomino

It actually seems like that it's building slower than before but I'm still peaking at right around a pressure of 8psi.

komat

please dont seafoam the motor... probalby do more dmg to the motor then help

just take it to a exhaust shop. ask him to see if theres a exhaust shop and how much would it cost to fix. most shops wont charge anything to look at it

accord_raffi

What kind of wastegate do you have? Maybe it's opening prematurely giving you the sound of a louder exhaust.

MrDomino

It's a Tial wastegate. I'm not sure what size or anything other than that. I can go check in the morning. I'll let you know what I find.

accord_raffi

I'm assuming it's the f38. If it was every taken apart, maybe it didn't seat right when it was put back together, or there is a rip in the plastic thing at the bottom of the spring. Just a possibility.

MrDomino

I wouldn't think that it's been taken apart. I know the guy who turbo'ed the car and he's definitely not the stereotypical noob that ghetto rigs everything.

Is wastegate failure a semi-common occurrence?

accord_raffi

Well he might have been changing out springs or something like that. A failing Tial is not very common, but the more times it's taken apart, the more it's open to the elements. I'm not saying your friend messed it up. Hell your wastegate might be fine. I just mentioned it b/c when it is open, it's obviously loud. Plus, you said your boost has been reaching 7psi, but at a slower rate which could be because the WG is partially open to begin with.

MrDomino

So after poking around, I found a leak between the exhaust manifold and the turbine. Are there typically gaskets in between them? If there are then who makes good gaskets? If not, I may try tightening it up a little but probably will take it off and check for cracks or something out of the ordinary although it was right between the two flanges so I just assume it's either a gasket or a broken bolt. I didn't feel any broken bolts though so I may have just blown a gasket.

Edit: After some research I found there is a gasket there so how about this?

http://cgi.ebay.com/ebaymotors/COMET...Q5fAccessories

I know Cometic is a pretty good company for headgaskets so I think this may be a good choice.

It actually makes sense that the leak was before the turbo since it did seem to be building boost slower than before but once you get to a high enough RPM, it had more than enough fluid power from the exhaust to hold the full 8lbs.

Thanks to everyone who helped! I appreciate it. I know it was kind of a noob thread but hopefully this will help someone in the future who knows how to use the search button.

JayRSXS

Use carb cleaner and spray around any possible solution. If theres a leak youll see bubbles good luck.

NonovUrbizniz

On the gaskets it depends on the parts. High quality turbo manifold will usually have the flange machined flat after everything is all welded up to ensure that it's 100pct flat.

A name brand good quality turbo will have a pretty much perfectly flat surface as well so in that case a lot of people will opt to run it w/o a gasket some people will use a gasket.

If the flanges/surfaces are not flat and true then you'll NEED a gasket.

Either way in your case since you're running not so high boost you're probobly better off just using a gasket.

And you can probobly pick up a gasket at your local parts store. They will have them for factory turbo cars... I think the 88 ford thunderbird turbo had a t3.

MrDomino

So after messing around some more today, I found that two of the bolts are missing from the flange between the manifold and the turbine. I think they may have been sheared off since I can't get new bolts to thread into the holes.

My next question is what is the most efficient way of removing the manifold and turbo? Can I disconnect the downpipe at the turbine outlet and then pull everything out? Or do I have to disconnect the downpipe at the cat and then pull it up through the engine bay? I'm not exactly sure how it went in so I'm not sure how to take it back out.