Tricks for finding exhaust leaks?

[turbojimmy]

Hi all,

I took my turbo off to port the wastegate. I've always had a leak over there but I'm not sure where it is. I thought maybe it was the turbo-to-header, but now I'm not so sure. I used some copper sealant (spray kind) on it and I can still hear a leak. I have a copper gasket as well as some Coppercoat brush-on sealant (thicker than the spray stuff) on the way but I'd like to avoid putting a gasket there unless I'm sure that's where the leak is.

I tried using a piece of heater hose up to my ear but can't pinpoint the leak. It's either the RH header, the turbo-to-header, or the downpipe. It's got to be affecting spool, too. The PT51 is a bit lazy off the line despite a high stall converter.

On the upside, my porting worked well. Seems to be sealing okay and boost is rock solid where I set it. I don't have to constantly watch the boost gauge now. It was creeping up *fast* before.

TIA,
Jim

 

[turbojimmy]

Thanks for the info. I'll try the cold check method first. It heats up fast, though.

Jim

 

[Rollin]

Ok, Jim this is Old School but it'll work plus it'll save you the burns to your hand from checking a hot exhaust Take the dowpipe loose if your running THDP it's easier, anyway seal the exhaust side of the turbo with Duct tape then recruit you best smoking buddy and have him blow smoke though a straw punched through to tape into the suspected leaking side of the turbo, the smoke will exit the leaking areas.... viola! leaks found.
HTH

 

[turbojimmy]

Originally posted by Rollin
Ok, Jim this is Old School but it'll work plus it'll save you the burns to your hand from checking a hot exhaust Take the dowpipe loose if your running THDP it's easier, anyway seal the exhaust side of the turbo with Duct tape then recruit you best smoking buddy and have him blow smoke though a straw punched through to tape into the suspected leaking side of the turbo, the smoke will exit the leaking areas.... viola! leaks found.
HTH

That's a good idea.....I'll have to get some seee-gars on the way home from work.

Jim

 

[Rollin]

Lol, No clogged passages for Carbs Steve, but it does locate those pesky Vaccum leaks around Intake sealing surfaces gotta look quick though

 

[chevyII]

old school

I used to find header to head and header to collector leak by putting the car in the garage. shut the door start your engine cold then shut off the lights,works best at night lok for the blue light sparking. easy!

 

[turbojimmy]

Thanks for the suggestions.

I found it, but I used a stethescope. I have this stethescope with a metal rod on the end that connects to a rubber hose. I took the metal rod off of it and put the rubber tube up to the header-to-turbo connection. HUUUUUUGE, big fat leak. That explains the lazy spool, too.

I'll have to put a gasket in there, I guess.

Jim

 

[77tech9]

I just took my whole exhaust and turbo off and redid everything.

(Other then fixing the crack in my header)

But I found a lot of problems, I have poston headers and they had a crack that I welded and fixed perfect (only passenger side), and the crossover had no clamp on it, and where the header hooks to the crossover was totally not tight enough.

I just bought this car a few weeks ago and already it's probially faster then it's been in 5 years.

Just make sure you use new gaskets on the headers, and turbo to header. Also my downpipe was leaking a tiny bit so I used some RTV RED and resealed it and it's perfect now.

 

[GN SBS]

Perhaps use some soapy water and watch for bubbles.
-S.

 

[GNut]

CLEAN..CLEAN..CLEAN

One very important thing to remember is to clean the header mounting surfaces on both the heads and on the header. I recently had a leak that was driving me nuts so I upgraded to a set of ATR's and copper header gaskets. When I pulled the old headers off (Poston's) I found that what I thought was a crossover sealing issue was actually a leak at the head on #6 cylinder. I put on the new headers and now had a leak on the drivers side...ARRRRRGH.. I pulled off the driver side header and looked at the new copper gasket and could see "rough spots" where it wasn't sealing correctly. Sure enough when I checked the head some of the previous stock style gasket material was stuck to the port. A quick buff with a scotch brite pad and re-assembly...WaaLaa.. No Leaks! I did notice that with the ATR's the exhaust tone changed to a deeper, throatier growl. All in all it was a lot of work and too much money to fix a simple gasket leak.