Vacuum leak

[Old_Paint]

Got a propane torch? Don't need massive quantities of propane to find the leak, and it's a hell of a lot safer than liquids. I keep beating this dead horse, so that I don't wind up with dead or homeless friends on these forums. Liquid solvents on a hot running engine are a very BAD idea. The propane torch won't put out enough gas to get dangerous. Stink, yeah, but blow up, no. With the nozzle, you can reach under the plenum curl quite nicely, and point the gas EXACTLY where you want it to go.

Is this a 5.0 or 5.8? If a 5.0, they're prone to plenum/intake gasket failures. Takes about 30 minutes to have the intake off the truck, ready to clean. I even pulled my injectors to check them for debris in the screens, and put new O's on them. Good time to CLEAN the throttle body and IAC the right way. Won't hurt to soak the plenum in Seafoam if there's some crud in it too. Just re-gasket the whole top end. After you get it back together, leave everything except the MAP and FPR disconnected, and cap off the nipples. Hook up the vac gauge on the nipple for the EVAP cannister, and check it again.

Should be something close to 20 inches vacuum. Start hooking the hoses back up, one by one. If the vacuum drops after connecting a hose, you just found the source of the leak. Sometimes, a tiny leak in the EGR will squeal VERY loudly, albeit a tiny leak. The shaft seal in mine is worn enough it squeals, especially on a cold engine, but doesn't warrant replacement yet.

 

[eco]

Smoke machines work good too...

 

[john112deere]

RE: smoke machines-

Since I'm a broke college student- could I get get away with using a cigarette or something in place of a smoke machine?

*I've got a slight exhaust leak I need to find right now, but this is really more for general knowledge than to fix my current issue...

 

[eco]

RE: smoke machines-

Since I'm a broke college student- could I get get away with using a cigarette or something in place of a smoke machine?

*I've got a slight exhaust leak I need to find right now, but this is really more for general knowledge than to fix my current issue...

On the ciggarette idea...YOU BET! Just unhook a vacuum line, take a big puff off of the cigarette, and blow into the vacuum line. Be sure to block off the vacuum line whil inhaling the next batch of smoke so that the smoke you just blew into the system does not leak back out thus slowing you down. Repeat this procedure untill the smoke exits through some place where it should not - at this point you have found the leak. For exhaust leaks, follow the same procedure, however you will need to cup your mouth over the tail pipe to induce the smoke to the system.

 

[eco]

is there such a thing as a Vacuum"leak detector" that 1 old cripple can use alone??

Yes, this is what I have:

Blow smoke into the system in question and in time smoke will come out of the leak. One cripple can easily do this.

Skan, a vacuum leak will cause a lean condition with MAF, and a high idle with SD. What good will a vacuum gauge do in this case??

 

[john112deere]

On the ciggarette idea...YOU BET! Just unhook a vacuum line, take a big puff off of the cigarette, and blow into the vacuum line. Be sure to block off the vacuum line whil inhaling the next batch of smoke so that the smoke you just blew into the system does not leak back out thus slowing you down. Repeat this procedure untill the smoke exits through some place where it should not - at this point you have found the leak. For exhaust leaks, follow the same procedure, however you will need to cup your mouth over the tail pipe to induce the smoke to the system.

I get the feeling you're making fun of me, though I'm not quite sure...

*I was thinking "smoke machine" along the lines of those little dealies you use to find air leaks in houses, for example- puts up a little puff of smoke. Anything that generates a small amount of smoke, like a cigarette (or a stick of incense, or a match you just blew out...) works just fine, and can be easier to come by.

 

[eco]

I get the feeling you're making fun of me, though I'm not quite sure...

I figured you were joking about the cigarette thing, so I added to the joke.

 

[lenny1carl]

it was a bolt on the throttle body(fingers crossed). backed out about 2 threads. i backed it out as far as i could w/out pulling the whole TB, a couple drops of thread lok, tourqued it down and seems good now. i did this in Jan and forgot to report it was done.
thanks for the input...especially the ones that could have caused explosions

 

[Lost]

Propane . Works motor will pickup when find leak . Works for me.