BMW M5 Forum and M6 Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
21 Posts
Discussion Starter #1
I've seen several posts concerning split vacuum lines, vacuum line T connectors, etc. Seems to be a commonly reported problem Does anyone have pics, vacuum line routing diagrams, common leak locations, general howto locate leaks, etc. as a guide to searching for these? Thanks in advance.
 

·
In Memoriam
Joined
·
4,624 Posts
I've seen several posts concerning split vacuum lines, vacuum line T connectors, etc. Seems to be a commonly reported problem Does anyone have pics, vacuum line routing diagrams, common leak locations, general howto locate leaks, etc. as a guide to searching for these? Thanks in advance.
That would be sweet, wouldn't it? However, I think it takes a trained, knowledgeable, and dedicated mechanic to find most of those leaks. You can certainly search for the ones that are "visual," with your own eyes. I suspect the BMW Technical Informational CD would allow you to find them, but I think, again, it would take a review of the entire CD.

If you find something, it should be a candidate for a sticky ... as it would be enormously helpful to most of us. (I have a very, very good, BMW trained mechanic do work on my 318ti and he missed an air leak that the smog check guy (an all car smog guy) found, and pointed out to me the next day.)
 

·
Registered
Joined
·
21 Posts
Discussion Starter #3
Thanks Daniel,
My experience is that there tends to be common points of failure in any model of vehicle, so how lines are routed affecting wear, components that turn out to be substandard / defective, etc. (can you say CPS?!). I was wondering if this is the case with vacuum leaks on the beast, or if they are more of the type you describe, no real pattern and lots of investigation on each vehicle. Thanks,
 

·
In Memoriam
Joined
·
4,624 Posts
Thanks Daniel,
My experience is that there tends to be common points of failure in any model of vehicle, so how lines are routed affecting wear, components that turn out to be substandard / defective, etc. (can you say CPS?!). I was wondering if this is the case with vacuum leaks on the beast, or if they are more of the type you describe, no real pattern and lots of investigation on each vehicle. Thanks,
My name is John, Daniel is the name of the guy who made the quote I listed in my signature. NO problem, though.

You are right ... most leaks, I suspect, come from age ... rubber doesn't last (at least, not in one piece) forever. And, sometimes from rubbing (along with age) against something.

I would only go searching for leaks if something changed on my car (i.e., gas mileage, idling speed or roughness, hissing sounds, etc.).
 

·
Registered
Joined
·
21 Posts
Discussion Starter #5
I am getting secondary air system codes, some idle drift, and some power loss at low rpms. Based on the many threads and number of vacuum leak complaints, this is my guess at the cause (not to mention a cheap fix if I'm right). Trying to study up some before I go exploring under the hood.
 

·
Registered
Joined
·
924 Posts

·
Registered
Joined
·
323 Posts
you could buy a smoke machine for a couple of grand from snapon or you can spray carb cleaner as the engine is running and when it rev's you found your leak. intake manifold gaskets have a habit of leaking as do MAF's and MAF boots. good luck.
 

·
Registered
Joined
·
19 Posts
+1 on the carb cleaner trick. You definitely notice the idle change when you hit the leak. Of course, with individual throttle bodies you're only gonna have leaks downstream from them or on associated vacuum lines. The plenum is just below atmospheric pressure, so any leaks are not as pronounced as on a conventional plenum that is downstream of a throttle.

Good luck.
 
1 - 8 of 8 Posts
Top