Vacuum problem??

[KevinsDriveway]

Hello guys, this is my first post on the 318ti forum and please forgive me for my english, because i am a german potato...

So 6 months ago, I bought an automatic 1997 318ti e36 with an M44 with 250tkm or 155 thousand miles. Everything worked great, no problems, changed some gaskets and the car was running smooth. I went to school and on the drive home I noticed a loud hissing noise arround the engine bay. I've lost nearly all the power and the car had big problems while running. When I gave is gas slow and steady its okay til like 2500rpm but if its on idle and i press the gas fast, it has like hick ups and stalls.

I am not a guy that knows much about cars but I got my compact to learn from it. And after watching a lot of videos, I often read 'vacuum leak' so I thought maybe this will be it. I don't know how to test and locate a vacuum leak, I also don't know for sure if this is the problem.

Maybe someone had similar problems and can help me solving it. I appreciate it!!

[two30grain]

the most sure fire way to find a vacuum leak is to do a smoke test. You have to have a smoke machine though.

The place I would check first would be the rubber intake boot. Usually massive vacuum leaks come from here. After the airbox (where the air filter is located) check for any obvious holes. Boots often have ridges where cracks can hide.

Good luck and I hope this wasn't too late.

[KevinsDriveway]

First of all, thank you for the answer.
So, I don't have a smoke machine, and the boot I already checked, but it seemed in really good shape and I didn't saw anything odd.
I think my next step is to start the engine and spray some brake cleaner on the connecting parts from the intake after the MAF, to the engine and watch the rpm

[two30grain]

good luck!

youll want to check every line that comes leads away from the the intake after the MAF sensor, some of it depicted here on realoem:
https://www.realoem.com/bmw/enUS/sho...diagId=11_6122

youll also want to check the hose going to the brake booster and the booster itself. if you dont find anything blatantly obvious (the ecu can compensate for minor leaks) you might want to go back to checking basic stuff like fuel delivery, spark, etc.

I'd also refrain from spraying rubber parts with brake clean. It'll dry the rubber out and cause more issues down the road.