legacycentral bbs

Hey guys, replaced the motor, exhaust manifold with a newer one, DP is now 3" non catted and I put new manifold gaskets, and I used copper on any gaskets I touched and I see no leaks.

Still have stock turbo and intake all resonators in place, yet as soon as I hit 3K its very loud IMO. I am thinking I should go over all bolts and make sure they are torqued to spec on the exhaust manifold. Also go over the DP. My DP isn't really mounted to the tranny anymore just floating. Possibly hits the tranny and creates the sound that way maybe? Still I hear some bafflely sounds sometimes when I open the door like a exhaust leak. Any tips for finding exhaust leaks? Thanks!

You hear the turbo whine or the exhaust?

What he said.I had a lot of leaks after putting my car back together and found that doubling up on certain gaskets was a really good way to go.Older bent and or slightly crusty flanges wont seal anymore with just one gasket.

Jack up the car and turn it on, should be easy to find an exhaust leak from under the car. If you still have trouble, have someone rev it up a bit while you're under.

If your talking about turbo whine, when I put on a 3'' DP, catless exhaust, and desnorked the stock VF-11 it got really loud.

If your hearing the tick of an exhaust leak, check the crossover pipe gaskets as I had a horrible leak when I first got the TLeg. If your having trouble finding the leaks you may want run some Seafoam through the intake per the instructions on the board, when you crank it back up any leaks will be smoking, ALOT.

Good luck

I cut and pasted this from an old post of mine, The nipple is right on top of the throttle body, just pull the vacuum line off.

For the little vacuum port I use about 1/3 of the bottle on a warm engine, connect a piece of hose and rev the motor and it will suck it in, you may need someone to help you do this as my step dad usually helps me, the motor will want to bog down so keep opening the throttle so it doesn't cut off, then cut the car off immiediately, let sit for at least 5 minutes , crank car and let idle till it quits smoking then drive it down the road to blow it out. When it's smoking I find this is also a good time to look for exhaust leaks as they will be really easy to see.

People say not to put it in that nipple because it might clean off some black stuff in the throttle body that needs to be there.

awesome idea will get a bottle. Also the issue only affects 90-91 afaik.

Apex3 wrote:People say not to put it in that nipple because it might clean off some black stuff in the throttle body that needs to be there.

Never heard this. I've been doing this for years and have had no ill effects. That black stuff, which is carbon and oil build up, will also cause a sticky throttle/gas pedal. Every time I have the throttle body off I clean the shit out of it, as far as I know there is no coating like teflon or what not. Some GM vehicles do have this coating and you need to use special throttle body cleaner.

Worst case scenario, you might knock some carbon off and it gets stuck between the valve and seat and not seat properly. This typically happens on very neglected vehicles that run poor quality gas and have a very dirty intake tract and valves.

Like I said, I've never had any problems and clean the entire intake this way at least once or twice a year as regular maintainence. Some people on here actually use plain water, I don't think it cleans as well and the smoke probably won't be as extreme. The reason I use this port is because it's central to the intake(all runners get fed), if you use a port that is not central it will get sucked into just that port.

ericem, if your just using this to find exhaust leaks you don't need to use a whole 1/3, maybe just a 1/4, DON'T USE THE WHOLE CAN. Whatever is left you can save or pour into the gastank. Read the bottle it has some good info, and this is also safe for O2 sensors and converters.

when you put the seafoam in and then start it back up, get someone to briefly hold a rag on your tailpipe. this will build slight pressure and reall pronounce an exhaust leak.