More idle issues after firing parts cannon to fix original idle issues

[Happy]

Originally Posted by 80stech

My neighbours Lamborghini sounds like it's about half open on start-up!

Gotta fill all dem Pots with air! LoL..!


E53 RiPPeR
XOuTPoST jUNkiE
ReVELaTiON 22:21

[80stech]

I think people walking by "fill their pot" too !

[wpoll]

Originally Posted by 80stech

I think people walking by "fill their pot" too !

Or empty it...!

[Bdc101]

Welp, spent most of my father's day putting everything back with a new CCV, new vacuum hoses, new o-rings for the vacuum distributor, new valve cover gasket, new intake manifold gasket, and cleaning and inspecting everything. No signs of vacuum leak or structural damage anywhere. Put it back together and it has the exact same symptoms. Idles rock solid for about 2 minutes until it warms up a bit, then idle surges from 1,200 to 1,500 rpm again.

Except now it has a strange honking sound whenever it's running. It sounds like it's coming from underneath the intake manifold. I can't pinpoint the sound but it didn't go away and doesn't sound right. I'm just gonna throw in the towel and find a local mechanic to look at it. I can't deal with this car anymore. I don't know how a smoke test would help since I have inspected and tested every single component that is exposed to vacuum or to the intake passage at all.

[80stech]

You have to consider that the entire crankcase is a potential vacuum leak. honk noise sure sounds like something to do with CCV or vacuum leak. No shame in throwing in the towel though. If it's not hard to get to you might try disconnecting the IAC valve or throttle just to see if that gives some direction for diagnoses. Is there less vacuum at the oil cap now?

[Bdc101]

Yes, there is still strong vacuum at the oil filler cap and at the dipstick tube. When I open the oil cap the honking noise goes away until I put it back on, so it's definitely a vacuum leak somewhere. I put the intake manifold on three times this morning before I got everything on right (first time I lost one of the little idle distributor inserts in the intake manifold when taking it off and only realized where it went after it was on, then the second time I had the valve cover vacuum line positioned wrong and it was impossible to remove it with the manifold on) so I might as well just take it apart again.



I'm gonna poke around with a vacuum hose and try to pinpoint the honking sound before I take it apart again though. Just putting one end in your ear and moving the other end around the engine bay helps to find where noises are coming from. I'm about done for the day though.



Found a youtube video that describes the honking noise exactly on bimmerfest, unfortunately it's yet another orphan thread with no resolution. Let me know if you have any guesses before I just start hacking things apart again: https://www.youtube.com/shorts/7axhHRMTa0s

[80stech]

I have mine set up a bit different but is there an easy way to disconnect and block off the vacuum from/at the vacuum distribution manifold? May be pull it off and plug the holes ?? If you have strong vacuum at the oil cap and a honking noise, it really points to a problem with the CCV. What do you mean by "idle distributor insert ??" I don't think it's really possible the way the CCV hoses are made but any chance that you have something mixed up ? Using a hose to find the sound is a good idea, garden hose or heater hose works great, I don't think I ever tried vacuum hose.

I just stuck my intake on tonight and had to lift it off the studs again and maneuver it a bit to get the knock sensor connector by the starter into the holder before putting it back onto the studs.

[Salty B.]

Old Frau Blücher idles just fine, but I also get a honk noise and what sounds like a pressure relief when shutting down. Like a short PHEWWW.

[Bdc101]

https://i.ebayimg.com/images/g/AgYAA...Aq/s-l1600.jpg

See those little things in the corner of the intake ports? Those are removable inserts, they can fall out when you remove the gasket. I believe they are for idle air distribution.


Gonna sleep on it and then figure out what to tackle tomorrow. I spent more time searching for honking on bimmerfest and found a few references to CCV problems, but mostly people thing that Salty B's symptoms are more indicative of a failing CCV. Will probably just take the whole thing off again. The vacuum distributor is a good idea to replace preventatively though.

[80stech]

I meant to block of the vacuum distributor temporarily for diagnostic purposes not to replace it. I didn't notice those inserts on mine. nothing seemed out of place or missing though so hopefully not going to be an issue with mine.