Hey All, Anyone have any other methods of chasing down vacume leaks besides using smoke machine? Would love to hear if you do. I think it's the intake gasket but am no positive. I have heard of spraying seafoam around and see when you get RPM change but am looking for alternitives.

Thanks Chris

 

A 2' length of fuel line, one end in your ear, the other scanning the intake.

A long screwdriver is great for knocks, tick, et. just promise not to hit any rotating stuff!! LOL


luck,greg

 

I've had some success with spraying carb cleaner at the suspected leak....but you obviously need to use a little common sense as the stuff is flamable ( which is why it works)

 

Years ago, b/4 I had a mech's stethoscope, I used hose and/or a piece of copper tube.

I saw a cool engine fire in a shop bay from spraying with ether. (that was b/4 the huffing craze)

luck,greg

 

I've tried a bunch of methods from the home-made smoke machine (smoke a pipe, blow into the intake and apply air pressure, which actually worked ok) to blocking off the intake tube and applying compressed air to the intake and listening to leaks (or spraying with soapy water and looking for bubbles - like a boost leak test for turbo charged engines). The best way I found was to disconnect the intake hose at the maf, block it with a surgical glove and duct tape, attach a small hose to the nipple off the intake manifold (the one people use for seafoam cleanings) and just suck all the air out with your mouth - vacuum pumps don't move enough air (no risk of over-pressurizing the system with compressed air this way). I found that by sucking as hard as I could , clamping the hose and attaching a pressure guage I could achieve about the same amount of vacuum produced by the engine. This seemed to work the best and you could watch the guage to see how long the pressure held too. I never could get carb cleaner or propane etc to work, I think you need a big leak for that method.

 

What is it you are trying to track down, have any fault codes, if so what are they?

 

Hey mike, after hours of examination and two pretty good savy engine techs , the general conseses is intake leak.. Louder at cold ...quiet or alsmot non existant when warm. Seeing it has had a head gasket job. i am thinking the intake gasket either was not changed or the bolt's where reused hense the slight deisel sound at load. I was figuring just changeing the intake gasket and bolts as well as valve cover gaskets to rule out thoes areas and its only under $100.00 in parts ans at least i could check the condition of the top end. I did have a couple codes ...lean ones that since i have changed out plugs. Idels and runs solid. Took a look in intake and looked a little brown. 122,000 miles and recient headgasket job with new heads. looking to pull pan before oil change as i just did a flush and oil change and have 1,500 miles on since. Just want to keep it in great condition as summer is here in florida and that means even at 7;30 at night its still 90 in the shade...I want to do i intake cleaning today ..let me know if you can give me a ring.

Thanks Chris

 

So, are you referring to your valley pan gasket or the actual intake manifold gasket between the upper and lower manifolds? The bolts do not need to be replaced but they can vibrate loose some times.

 

Hey Mike, Which one would you think? The intake gasket is pretty easy as the rocker covers to do or at least check the tightness of the 4 rocker cover bolts you cant get to because of the intake covering them. i could also replace the wires as i now have easy access. The inlet manifold would be the next place to check tightness or replace if that is where it is leaking. Which would you think would be more suspect? I would rather spend a weekend now at this stage getting it corrected so i can enjoy and drive it without having to constantly fix it. I like to be a bit preventative. I still cant stop constantly keep from looking at the temp gage all the time. I must have been mentaly damaged from my other LR...

thanks chris