alright, how does one inspect vacuum leaks?

[BennyM]

My M50 is idling rough so I think of various things to check. One of the main things is vacuum leaks. I've never had to do much work on the engine. I've replaced a few hoses with no luck. New filters, new coil packs, 10 mo old plugs. So how do you "check for vacuum leaks"? Do you just run your fingers along the hoses or spray something near them? I don't know diddly about vacuums. Thanks.

http://www.bimmernut.com/wwwboard/e34/messages/18504.html

[MarkD]

My M50 is idling rough so I think of various things to check. One of the main things is vacuum leaks. I've never had to do much work on the engine. I've replaced a few hoses with no luck. New filters, new coil packs, 10 mo old plugs. So how do you "check for vacuum leaks"? Do you just run your fingers along the hoses or spray something near them? I don't know diddly about vacuums. Thanks.

http://www.bimmernut.com/wwwboard/e34/messages/18504.html


Do you have a propane torch? Open the valve a bit and without lighting the torch, move the nozzle end around the suspect areas. If propane gets in via a vacuum leak, the engine idle speed will change.

Mark

[MBXB]

Here's how one of my Corvette buddies does it:

Locate all the possible vacuum leak points, then run an UNLIT propane
torch along each point. When the engine smooths out or idle increases.. you've found your leak. Easy on the propane setting.. keep it light.

[MarkD]

Here's how one of my Corvette buddies does it:

Locate all the possible vacuum leak points, then run an UNLIT propane
torch along each point. When the engine smooths out or idle increases.. you've found your leak. Easy on the propane setting.. keep it light.


That's a great tip!

[winfred]

i also use carb cleaner, it's less effected by air comming from the fan

[Javier]

nt

[BennyM]

I'll get me some carb cleaner.