What to use to check for intake leak??

[Hurley711]

What is it that you can spray around teh intake manifold to check for a leak? Is it brake cleaner that will make teh emgine surge if there is a leak sucking it on?

[redline]

i use carb or brake cleaner just try to stay away from electrical components. And yes if its a significant leek the motor will surge or bog out.

[oneBADDz]

depends which brake cleaner you use, many of the newer ones aren't very flamable at all due to trying to be environmentally friendly the fun ingredients were removed. If you get the right brake cleaner it'll work great it's some wicked stuff but it's bad on paint and rubber though. B12 isn't so bad on rubber or paint. Whatever you use, don't spray in excess as insanly bad (yet fun for anyone who doesn't own the car) things will happen. I'm gonna go see if mine is flamable

[oneBADDz]

Mag1 non-chlorinated is definitly one you could use. . .lol. You can get it and any parts store. A hint that it would work is the warning: FLAMMABILITY, FLASH FIRE, EXPLOSION, BUSTING HAZARD I really don't support using brake cleaner though, it's too volatile and sprays a very large quantity with a lot of force. I'd use B12, someone else might have an even safer suggestion though

[Hurley711]

Thanks, after cam install my idle drops to 500 RPMs at times. I want to make sure it's not a manifold leak, car was tuned, hoping it's not th etune that is the problem, it's only a 224 cam:thinkin: Would a leak cause the RPMs to drop to 500 or would a leak cause them to surge? It only happens when I am coming to a complete stop, at or under 5 mph

[oneBADDz]

have you looked into little stuff like the pcv valve? that little bugger can cause more trouble. . .or just a bad hose running to it. There aren't a lot of vacuum hoses that it would likely be, look around the intake, and maybe just spend $2.49 on a pcv to try it. Any codes?

[Hurley711]

Yeah it sets a SES light when the car dips to 500, idle is set to 900 so when it drops to 500 th ecomputer sets a lean code. TB was swapped out with a stock one and that didn't cure it. Where is PCV valve located?

[oneBADDz]

side of the intake somewhere, don't remember to be honest, should be rather close, with a short hose connecting it to the intake. I have trouble remembering location differences between my LS1 and LT1, I think driver side? don't trust me on location though

[oneBADDz]

but if it sets a lean code it could be that you are losing fuel pressure, I'm sure you've heard all of this already though

[Hurley711]

Z- sent you a PM

[oneBADDz]

i got it, i read half of this before, gotta finish it though

[Hurley711]

i got it, i read half of this before, gotta finish it though


Please send me any suggestions you have, does it sound like a leak or the tune to you?

[oneBADDz]

I really know zip about tuning, but I wouldn't say it's the tune. I would think it's sucking air somewhere, bad pcv etc. Your brakes work as good as new or do they take a little extra effort? Look into little stuff that could have been overlooked or that might work just a little worse than they used to. Anything with vacuum lines. Cam cars can have problem providing sufficient vacuum at idle too even with everything else working fine

[oneBADDz]

oh yeah, you ever look into that cracked intake?

[GOODZ/BADZ]

Use starting fluid to check for the leak. Any unmetered air could cause it to run lean so check from the MAF back to the manifold also.

[Hurley711]

Tuner said he sprayed the intake and nothing sucked in, I wanna try again just to make sure. Guess it's gonna come down to putting the LS1 back on to make sure. Where are the vacuum lines at exactly?