Vacuum leak

Dec 29, 2003 16 Replies

My Jeep just developed a vacuum leak... a high pitched squeal only at idle after it heats up. I have look and checked hoses but have not found it. I saw a friend (on another vehicle) use ether, and look for increased idle to find a leak (but never found it). Is there another method?


-- JimG



80' CJ-7 258 CID
35" BFG MT on 15x10 Centerlines D44 Rear, Dana 30 Front. SOA
4.56 Gears, LockRight F&R Dana 300 w/4:1 & Currie twin sticks Warn X8000i w/ dual batteries

Try spraying carb cleaner, fuel injector cleaner, or WD-40 at the vacuum hoses and their connections. Either will cause the engine rpm to change when it gets sucked into the engine through the leak you just sprayed.

Jerry

And the carb base bolts while there...

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

"L.W.(ßill) Hughes III" wrote:

Ditto on the bolts. I just replaced the belt on my 89 YJ because it was squealing, New belt same old squeal. sprayed water from a squirt bottle at various suspected points and found that a bolt on the intake was loose. Tightened it and the squeal vanished, but not the bill for the new belt.

I just noticed that you said your friend used Ether to check for vac leaks....... Jim this doesn't seem like a good idea to me as Ether as we all know is quite volitile. I would use carb cleaner and listen for the engine to stumble as it gets sucked in the leak, carb cleaner is not very combustable.

ah yes.......ether. While in phy school, one of my closest friends (no longer here - died @ age

36 from a stroke) tried to start his car with ether. He had his mother crank it over while he sprayed the ether down the carb. I was just walking up to see what he was doing & the engine back fired & died (lucky). The only problem was that a small spark had jumped up into the middle of his head. He had a large cloud of smoke coming from the top of his head & he didn't feel a thing. I guess he saw the look on my face & he turned and looked at his reflection in the window - we both panicked, put it out with a jacket or something & then while still down on the lawn we busted out laughing about how he looked like he was in some cartoon episode with the smoke billowing from his head. I guess it was mainly one of those nervous things you do after what could have been a tragedy but , thank god, was not. His mother got out of the car, called us something in Portugese & didn't speak to us for several days. My wife was behind me, & we laugh about this once or twice a year.

Had a similar problem on a '79 258, retorqued the intake manifold and the squeal went away.

I've seen folks use canned ether and know it works. But, I just don't feel comfortable blasting copious injections of ether onto a hot engine. That can't just be me, can it? o_o_o_o Best Regards, /| ,[_____], Jim, WP3JQ |¯¯¯L --O|||||||O- ()_)¯()_) ¯¯¯¯¯ )_) EM60qk 30.447439N 086.628959W

Drink did pass the time by typing:

Use throttle body cleaner, works the same and is much less flamable. Some folks also use propane.

Or use soapy water on the vacuum lines.It will bubble up @ the leak.

Have sence,patience,and self-restrain,and no mischief will come.

I want some of what you are smoking.... ;-)

Vacuum lines 'usually' suck eh.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

mctiger wrote:

Yeah, that works, but the hard part is shrinking yourself and your scuba gear down so you can fit inside this vacuum line and still be able to breathe. Hint: bubbles on a vacuum line would only appear on the *inside* of the line.

jerk

Have sence,patience,and self-restrain,and no mischief will come.

WD40 works for me every time and will not explode. john

Well, usually if I am trying to make some smart assed reply without calling someone stupid or something, I will use things like this: ;-) It is supposed to be a wink.

I know you just mixed up the Air Conditioning system with the vacuum system, but hey I tried to be funny, sorry if I failed.

Mike

mctiger wrote:

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