HELP, 1995 740IL Rough idle, and loud hissing

[SE7EN40RTY]

Any Advice will help.

Here is my situation, I have 1995 740IL. Last week I started my car and noticed the idle was extremly poor, A few days later I started the car again on a cold start and white smoke came out of the exhaust. Since then ...

-I've ran some BG-44k Which the dealer said they wanted to try, instead I did it myself for quite a bit less. I ran it through and no changed after 500 miles.

-I then changed the plugs, I noticed on the plugs a few of them were oil soaked. I had platnium 4's in there, which i heard don't work well anyways. I put the BMW OEM ones then Supers. Still no change. The idle is still rough, and smoke is still appearent.

I was reading on here One person had this problem and he changed his oil sperator, another was suggested to change his head gasket, and all other seals on the top end of the engine. I'm very fimilar with cars and can do the work myself, but I'm lost at where to go next. I don't want to do any work and notice it didn't work. I truly hope there is someone who can help me. I really appreciate what all the people on here do for each other. It's good to know that there are people other who are willing to help with out money on their mind. Thanks again everyone. please reply to momentum59@yahoo.com or call me at 303-667-5620 I'm free all day.

[SE7EN40RTY]

Almost forgot, also at idle my engine makes a whirring sound almost like a mermering but constant...

Also, the loud hissing has been with the car for awhile, so long that I thought it was normal, Until I heard another 7 series engine. The sound comes from the far back end of the manifold. I Think this might be a seperate issue. But then again I don't know.

HAHA it sound like my car is falling apart with all these different sounds.... wonderful. Thanks again for any help.

[vermont]

It's a vacuum line. Mine went bad a while back. It's back by the firewall.

[Sean]

Yeah sounds like a vacuum leak start the car find the source of the hissing and replace the gasket or pice of rubber that will seal the hole.

[Big Dog]

on the archive, just do a search.

[SE7EN40RTY]

Thank you very much for replying, I truly appreciate it. Thanks to Big Dog, Sean, and Vermont.

I feel like these are seperate issues to be honest. Their time off occurence is total seperate. I hope i'm not confusing everyone out there. Thanks Again.

[SE7EN40RTY]

Thanks guys for all your help. I went to the dealer this morning and bought the separator, and two and a half hours later it's runnin smooth again. almost smoother than ever. I also think i did it in record time please feel free to contact me if anyone needs help with this in the future. Thanks Again everyone.

[cris88]

hello se7en40rty, i am experiencing the same problem, rough idle and hissing sound . today I replaced my plugs to the OE Bosch but to no avail. i am not a mechanic but already learned a lot from this forum, great people, recently replaced my drive shaft too. i'd like to try the oil separator that fixed yours, how much did parts cost you, do you have detailed posts, pictures? appreciate all the help.

[DocStrange]

2.5 hours? Wicked! I tried short cut of prying off old diaphragm cap, snapping the one on from new OSV really proud of myself cause it took less than an hour...then I started car and kept blowing smoke. Another $75 OSV and WAY more than 2 hours fixed it.