just like the title suggests, how do you trace down a air leak? this would be on my newly turbo'd 6.2, im using a banks turbo/manifold, intake off a 97ish 6.5, and a homemade pipe between the two. any ideas???

on my gasser we took starting fluid and listened to when the motor would change idel when it was sprayed near that cylinder...

If it's in the pressurized part of the system, use soapy water. Bubbles=leaks.

I would stay away from the starting fluid and maybe use some WD40.
Ted

I'd go with soapy water (heavy on the soap in this case). Starting fluid and carb cleaner work well when you are looking for a vacuum leak on a gasser but there is no vacuum on a diesel. We're looking for post-turbo pressure leaks here.

well i checked the entire system out, and cannot find any leaks, but cant figure out why im only getting about 4-5 psi max boost. any ideas on that?

well i checked the entire system out, and cannot find any leaks, but cant figure out why im only getting about 4-5 psi max boost. any ideas on that?


How are you controlling boost?

How are you controlling boost?

Its a banks turbo= non wastegated, so no way to control boost.

You have to create a vacuum in the system for the ether or WD40 trick to work. You are going to have to figure out your own dimensions but here is how you do it:

Take a fairly thick (3/4" thick) but small size (5"x5") piece of plywood and drill a hole in the middle. The hole does not to be very big, you only need enough air to pass through the hole to let the engine idle. 1/2" might be a good starting point. You need to cover the turbocharger inlet with the peice of plywood once you have it ready to use. The engine will create enough vacuum to hold it in place over the turbo inlet once the engine is running. Do not rev up the engine.

Now the ether trick will work while the engine is idling. Just short bursts with the ether in suspecting places like the intake manifold and turbocharger connections. The ether is relatively harmless in moderate amounts if the engine is already running and it is way less messy than the WD40. I have used both and they both work fine.

Hope it works for you.

The soapy water method under boost might work if you have a chassis dyno where you can load the engine up to boost pressure and then do the test. If not you will have to pay one of your freinds to ride under the hood with a spray bottle and a flashlight.

Well, instead of the fancy dyno trick you can do what I used to do tuning two cyl. pulling Deeres, chain them to a large tree. You could aslo stand on the brakes and load the engine if it is an auto. Either way use extreme caution.

I would not use a plate to block the intake on a turbo unless it was an emergency to shut it down. Creating vacuum on a turbo is not good for the seals. Have you ever seen a diesel run on it's own oil? When the let go it's impressive!!

Compound turbochargers often have vacuum in between the compressors with no issues.

I have also seen positive air shutdown systems on oilfield trucks installed pre-turbo, no issues.

Have you ever seen a 2 cycle detroit run away? Pull the air shut down on it, suck in the blower seals and watch it SCREAM!!

Turbos can suck seals in. I would not chance it.

Hey if you want to argue about it all day that is fine with me. Go ahead and check some of the manufacturers manuals for checking for air leaks. The way I described is the same way many manufacturers suggest doing it, just with a piece of plywood and not a two hundred dollar specialty tool from the stealer.

I have never seen any manuals suggest tying anything to a tree, loading the engine and then walking around to the front of the vehicle with a squirt bottle. I almost fell off my chair when I read that. I thought you were kidding but I guess you are not.

I also see you are a Ford and Dodge driver. Where is your GM? Who can take you serious on a Gm forum if you dont own one. No go back to the Ford forum.

Cool it guys.

I don't have personal experience on whether or not turbo seals can be damaged by vacuum but I'm going to guess that that would have to be a pretty sensitive seal to get pulled out like that. Consider that the seals retain pressure of upwards of 60 psi from the inside, why not some vacuum from the outside? It isn't going to be anywhere near the equivalent of the oil pressure it sees and it is basically the same force that pulls on it. Then again, maybe if the seals are already in lousy shape to begin with and you add the vacuum to the oil pressure...

Whether or not you drive GM you are welcome on this forum if you ask me. I am not for one brand more than the next. If you ask me they are all pretty much the same anyway... They all go down the road and they all have issues eventually. If you want to get into the old Ford vs. Chevy discussion you can leave me out. I've owned both and they've all been decent. As far as Dodge that is fine by me as well. I'd have one if I could afford one with a Cummins. I always liked the older Dodge body styles. By the way, Oilburner350 doesn't have a Dodge in his sig. All Fords if you read through it.

In addition, Fords and Chevys both run on the exact same principles (guess what, they're both trucks and they both have engines). If you understand the principle behind a Ford you understand the principle behind a Chevy.

Why not just pressureize the engine with a smoke machine designed for automotive testing ?

ill try the board thing tomorrow, thanks jasonsmack

Why not just pressureize the engine with a smoke machine designed for automotive testing ?

i would, if i had one, or even had access to one, but i dont so thats out, but thanks for the idea.

Hey if you want to argue about it all day that is fine with me. Go ahead and check some of the manufacturers manuals for checking for air leaks. The way I described is the same way many manufacturers suggest doing it, just with a piece of plywood and not a two hundred dollar specialty tool from the stealer.

I have never seen any manuals suggest tying anything to a tree, loading the engine and then walking around to the front of the vehicle with a squirt bottle. I almost fell off my chair when I read that. I thought you were kidding but I guess you are not.

I also see you are a Ford and Dodge driver. Where is your GM? Who can take you serious on a Gm forum if you dont own one. No go back to the Ford forum.

Yeah, I almost spat out my juice when I read that, damn. :D

Cool it guys.

I don't have personal experience on whether or not turbo seals can be damaged by vacuum but I'm going to guess that that would have to be a pretty sensitive seal to get pulled out like that. Consider that the seals retain pressure of upwards of 60 psi from the inside, why not some vacuum from the outside? It isn't going to be anywhere near the equivalent of the oil pressure it sees and it is basically the same force that pulls on it. Then again, maybe if the seals are already in lousy shape to begin with and you add the vacuum to the oil pressure...

Whether or not you drive GM you are welcome on this forum if you ask me. I am not for one brand more than the next. If you ask me they are all pretty much the same anyway... They all go down the road and they all have issues eventually. If you want to get into the old Ford vs. Chevy discussion you can leave me out. I've owned both and they've all been decent. As far as Dodge that is fine by me as well. I'd have one if I could afford one with a Cummins. I always liked the older Dodge body styles. By the way, Oilburner350 doesn't have a Dodge in his sig. All Fords if you read through it.

In addition, Fords and Chevys both run on the exact same principles (guess what, they're both trucks and they both have engines). If you understand the principle behind a Ford you understand the principle behind a Chevy.

Pressure and vacuum are 2 different animals and just because its designed to take pressure, doesn't mean it can take vacuum, and vice versa. As far as turbo's go, they should be able to take vacuum and the board idea seems like a sound one.

well guys, i did the board thing, which worked great, found my intake gaskets were leaking, but, now i seem to have ALOT of blowby, did i screw something up? its always had a little blowby, but hardly noticeable. so???

Are you running a turbo CDR?

Could be the engine was borderline and adding the turbo has caused the blow by. :(

Are you running a turbo CDR?

Could be the engine was borderline and adding the turbo has caused the blow by. :(

i dont have any cdr on there, but the blowby has quit now pretty much, just bact to the way it was before.

i have absolutley no air leaks between the turbo and engine (intake side), but for some reason it doesnt seem to be making much boost (1-2psi wot 4th gear), i know my gauge is good and working properly, anyone have an idea on that?

I am not too familiar with the Banks turbo, so how is the boost regulated? there has to be some sort of wastegate can? Got pics? The turbo's can't be left to run WOT without some form of regulator otherwise they'll produce 20 or more psi.

Banks has no wastegate just sized to engine to give approx 13psi max. You should be making more boost than that. Have you turned up the fuel yet? The turbo forces more air in which then needs more fuel, which will make more heat and exhaust volume to turn the turbo faster, which will force more air into the engine, that needs more fuel, guess I can stop now, you get the picture lol. Does the turbo impellar spin freely?

What is your rpm sitting at when you have your low boost condition? What is the most boost it seems to peak at and at what RPM?

Can / did you double check your boost guage? A bit of oil or crud may have plugged up the signal hose or got inside your guage. An el-cheapo vacuum/fuel pressure guage from the local auto parts store is a handy backup tool.

Any sort of an exhaust leak, even a small one at head or the donut can have a huge effect on your boost level. Check around for some carbon and soot on the exhaust system leading up to the turbo.

I assume the exhaust post turbo is free-flowing. If you have a 3 1/2" exhaust with a decent size muffler that would be plenty. A choked muffler will kill the boost.

I do not think the old Banks or ATS systems had any sort of wastegate or boost level control. They were simply sized correctly for the engine displacement and rpm range. The ones that I have seen have ranged from 5psi to 12psi boost. Many of them did not really make significant boost until the rpm was higher than the normal operating speeds.

Keep the info coming, we will sort it all out somehow.

Tracy has a great point about the fuel. The kits generally came with directions on how to and how much to turn the fuel up.

i had the fuel turned up previously when it was n/a, i had it up 1/2 of a turn,got a nice smoke show when i got on it =) and ran it that way with the turbo but couldnt keep the egt's down, so i backed it off 1/4 turn and now it doesnt smoke at all, but if i get on it i can get the egt's up around 1000-1050 which i thought was just about perfect.

now, i dont know if this is normal or not, but if i put it in 5th(od) it is absolutley impossible to maintain speed, the turbo acts like a giant restriction in both the intake and exhaust. before when the pump was turned up more, it would really go in o.d. but got really hot really quick.

on another note, the turbo spins very easily, and has very very very minimal play.

I am glad that you found your leaks on the pressurized intake.

This is the kind of thing that I was talking about. I had a 6-71 runaway from me once. Not too cool.

http://www.motorwatch.com/automotivebible/mechanics_nightmares/mnm09.htm

http://www.mercedesshop.com/Wikka/RunAwayDiesel

While you're having fun, keep watch on the EGT's, those 6.2 pistons don't like high boost. Most of the 6.2 turbo kits I've seen run about 6-10 lbs. boost. The EGT's vary but if the pyro probe is just aft of the turbo outlet (like some of the kit's instructions say), anything above 950 has produced some engine problems down the long road. The forum archives are full of broken piston/blown head gasket stories.

Great info on the CO2 to stop a runaway Diesel, :cool:

But by far the worst story I know about an exploding engine happened on a diesel-powered car. Those of you who have been around the diesel engine trade know about the horrible automotive diesel engine that GM made. They modified the 350 gasoline engine to run on diesel. Big mistake. It was never designed to hand that kind of compression or torque. When trying to get one to start, a mechanic was shooting ether into it. The engine exploded, blowing off of the cylinder heads, which dismember one of the mechanic's arms. But that's another story.

Wow, that is insane, :(

so should i try turnin my fuel up a little or look for something else?

Quote: (But by far the worst story I know about an exploding engine happened on a diesel-powered car. Those of you who have been around the diesel engine trade know about the horrible automotive diesel engine that GM made. They modified the 350 gasoline engine to run on diesel. Big mistake. It was never designed to hand that kind of compression or torque. When trying to get one to start, a mechanic was shooting ether into it. The engine exploded, blowing off of the cylinder heads, which dismember one of the mechanic's arms. But that's another story.)

I think that story is one for myth busters. I know for fact that the 5.7 Diesel that is mentioned was not a converted gas engine that is complete myth. And wasn't in many ways a bad engine.

Tom is your pyro before or after the turbo? I would think 1100f pre turbo is max.

Fred I'm a land lubber don't know my port from my aft lol.

well guys, i found my air leak (yes, an air leak) the seals on the turbo are leaking oil into the intake side, so, its my thinking that if oil can get in, air can get out....no wonder when im making a little boost my oil pressure jumps waaaaayy up!! does anyone know where and how much a new turbo or rebuild kit would be??, if i have to get a new turbo, should i get one for a ford-IH 6.9?

If your turbo shaft has very little end play, the turbo can be rebuilt fairly cheaply. US Diesel parts rebuilds turbos and sells kits, there are many others. If you have a C code IP, you will be challenged to get enough fuel to make a lot of boost without changing the fuel delivery valve. Fuel=boost, more fuel, more boost. More fuel with a turbo that isn't creating boost will result in high egts. More boost will cool the egts.

The way I like to test for leaks is to make an adapter that goes over the intake side of the turbo. Rubber plumbing reducers work well. Most turbo's are around 4 inches on the intake, reduce the other end to 2 inches and insert threaded pvc fittings with a tee. On one side of the tee, install a gauge, on the other fitting, install a coupling to hook up a regulated air supply. Adjust air pressure to about 20 psi. This will pressurize the entire intake system (very helpful with intercoolers). Hope this helps.

^^^^^^^^^ a good pressure regulator is a leakdown tester. Most will go from 0-100 psi so you have lots of fine adjustment. Thats what I use when I check turbo systems for leaks.

ok, i called banks today, and the thin film of oil is completely normal, its not that much oil after i tore it apart, everything is in very good shape, so basically im back at square one, i have no leaks anywhere, ive been over the entire system countless times...so i have no idea what now. im afraid if i turn the pump back up ill burn up the motor, its already runnin 1000-1050 as is so im nervous about turning it up.

Tom are those pre or post turbo temps.

Tracy, those are pre turbo egt's

As stated earlier, make sure you don't have an exhaust leak. Check the cross over pipe connections, where the turbo bolts to the manifold and the manifold bolts. Exhaust leaks will spike egts and kill boost. You need boost to drop egt's. Also check for restriction in air filter. Crank the fuel back up and find the leak. It is there, you just need to find it. Also make sure that you don't have a restriction in the exhaust pipe.

i turned the pump up 3/16 more, it has alot more power,and now im can get up to 4 psi boost, and the egt's dont really go over 1100, maybe +/- a few degrees. when i put the turbo back on i coated the flange where it bolts on with grease, as i did the manifold when i put it on. so basically ive got it narrowed down to either the drivers manifold ( which has no soot around it), or the crossover pipe, which leads me to my question, how little of an exhaust leak will afect the turbo? why i ask is am i looking for a big leak that i can hear? (which i dont have) or something as little as a pinhole?

Banks' non-wastegated turbo is only good for 4-6psi Boost on a 6.2-6.5 - the system is designed for towing improvement, not stoplight racing - the Banks wastegated Mitsu TE06H upgrade for the Ford 6.9\7.3 would be the turbo of choice - requires slight mod to the down-pipe, but gives low-rpm spool and higher Boost levels, similar to the GM-X series - the turbo installation should have required new intake manifold gaskets, as the old, tired, heat-hardened oem gaskets had no vacuum or pressure to deal with, so leaks would not be noticeable, pre-turbo era

Sounds to me like it's all working as designed, no problem

Boost sounds low at 4psi.

Ditto on checking x-over connections/pipe for leaks.

If you're using the springs and nuts on the xover at the manifolds (hardware from stock exhaust) then that will create a problem as well, the springs won't hold the pipe flare against the donut well enough for a seal.

Turbine size.

There were TWO T04B turbine housings that were used with 6.2 Banks kits.

In the early kits they offered a 1.15 A/R ratio turbine housing for heavy trucks that tow heavy. Basically ur 1 ton CC 4x4 dually. Then they offered a 1.00 A/R turbine for everything else.

The current offering is just the 1.00 a/r turbine with a more efficient compressor wheel in the housing than previous versions.

Check your A/R on the turbine housing, it will be on the snail near the T3 flange.

I've used both the 1.00 combination will get you 9psi at WOT running near engine govenor (3800 shift point on A4 700). Hard/medium acceleration will grant you around 4-5psi.