New Member - Need '84 325 Idle Help - BMW Forum

Speedemon636 · 10-04-2009, 08:01 PM

Hello all, I'm new here and currently have an idle problem with my car. Like the title states, it is a '84 325. When it starts, the rpm goes up to +/-3k and then comes back down after about 2sec. Then it revs up and down between +/-1k and 2k while parked.. I'm sure it's probably just a sensor, but I'm not sure.. And input/suggestions would be greatly appreciated! Thanks!

-Matt

prosavage2600 · 10-05-2009, 01:45 AM

Check your idle control valve. Its the little silver thing on the top of the intake manifold. They go out all time. Usually because they suck up junk from the engine. Give it a good cleaning and see if that helps.

http://www.pelicanparts.com/BMW/cata...uxairvalve.jpg

marti5 · 10-05-2009, 03:12 AM

Sounds like the Air flow meter to me.....

Speedemon636 · 10-05-2009, 11:27 AM

Thanks for the responses! I'll defiantly give both ideas a good looking into!

marti5 · 10-05-2009, 11:32 AM

If you unplug the air flow meter with it running and there's no difference or it dies or revs right up, thats the problem and will need to be replaced and if it is dont by a cheap one from ebay, Bosch or siemens is the way to go....pref Bosch

Speedemon636 · 10-05-2009, 03:17 PM

Tried idle control valve and didn't do anything different so I swapped one I know works and still did the same revving.. Where is the air flow meter? I'm new to working on bimmers although I know just about everything about motorcycles

marti5 · 10-06-2009, 02:40 AM

It will be situated twix your air box and air intake,looks like this:

BMW E30 Mass Air Flow Meter AFM MAF 325is 325ix M20:eBay Motors (item 220484409581 end time Oct-22-09 13:35:05 PDT)

I presume you have an E30

Speedemon636 · 10-06-2009, 07:00 PM

Correct on the E30. So if it's running and I unplug the air flow meter and it dies, that means?..

marti5 · 10-07-2009, 09:12 AM

please see post #5

Speedemon636 · 10-07-2009, 07:29 PM

Ooh sorry I misread post 5. Thanks for your help! I'll see if that cures my problem!

silversled · 10-07-2009, 09:24 PM

no, you guys are missing something. On every 325 anything it was Motronics.
with Motronics there is an idle control valve, but there is also a partner control unit for said valve. this control unit is the size of a pack of smokes and sits on top of the main control unit, which resides in the attic of your
glove compartment. check it out....fact is, the idle control valve is run by
this little controller...typically you need to replace the electronic control unit and clean the actual mechanical valve out with Gum-Out or something until you can actually blow through it like a straw and hear the valve work...sometimes you have to replace both as they can burn each other out.
I had a 533i that this very same thing happened too....