Trying to find VACUUM LEAK- Need advice

[Warren N.CA]

vacuum line I could find, looking for something amiss. So, I haven't really isolated it to the dipstick area. Now I need the car to cooperate by going into the failure mode again (Or else decide that it's fixed.).

Thanks for the additional tips. I may just start replacing hoses, if it happens again. I'll be clearing the code soon, so I can start fresh.

BTW, I carefully torqued the valve cover over its new gasket, to the specified value, about 2 weeks ago, after valve adjustment.

Jeff, you're certainly right about keeping crap outta the oil pan, etc., and normally I'd go with a new gasket. But, here in East Bumphuk we ain't go no stinkin' BMW gaskets at Billy Bobs' Parts 'n Bait shop. So, until I can get a fresh new one from BMA, I used the tube of stuff that's worked flawlessly on my other cars for the past couple of decades: After careful study, I've not yet seen it to crumble off and go elsewhere, so I'm gambling that the risk of errant sealant is less than that of leaky gaskets, for the next little while at least.

Warren, if you jostled the dipstick, etc. and "temporarily" fixed the problem, then you're probably getting pretty warm as so its source(s). In all likelihood, you have SEVERAL small leaks which collectively skew the electronic input to the fuel injection. So, keep after the basic stuff as mentioned previously.

The best advice I ever got regarding vacuum leaks came from a service guy at the Nissan dealer where I got parts for my '78 280Z. That car had L or J Jettronic Bosch fuel injection, so was essentially similar to our cars. After years of chasing hesitation, stumbling, erratic idle, sluggish performance, etc. , this guy said "90% of the time it's a vacuum leak." So, I used to carry a razor blade in the glove box, and trim 1/4" off the end of offending vacuum tubes, then just push them back on the barbed vacuum fitting. (I was amazed that a leaky tube for the heater control could also cause trouble with engine idle, but it did.) Trimming the tube tip off worked every time, cuz the leak is usually where the stretched rubber tube splits at the barbed nipple. Not always, though, so just buy several feet of new vacuum tubing at Billy Bobs and spend tomorrow afternoon checking things out. BTW, these tubes are pretty good as stethoscopes: Stick one end you ear and hold the other end at various spots that may be leaky--you can hear if it leaks. Intake manifold, brake vacuum assist, window seals, etc. etc.. Keep some coiled up in your tool kit or with the spare tire for such purposes.

[MBXB]

Unlit Propane Torch
A 'Vette buddy uses an unlit propane torch and passes it near every suspected area as the engine idles. When the rpms increase, you've found a leak.
He claims to be able to isolate every one.