Subject: Idle Control Valve (ICV): Removal, Cleaning & Refitting Author: shogun (moderator) : member since March, 2004 : 12553 posts Posted on: 2008-04-21 08:35:55

Cleaning the I.C.V.

As a relative 'newb', I was apprehensive about messing with the I.C.V so I tried to do some research on it. I couldn't find a write up on it so here it is. It's a piece of piss but hopefully it will help someone out at some point.

(I actually took pictures when re-fitting as I only thought about writing it up then incase anything looks iffy! Also, the small rip in the big air hose was there beforehand... Doesn't cause an issue at the moment luckily).

Benefits
The idle on these cars can be lumpy and problematic, cleaning the ICV is a cheap and easy first step to try and remedy the problem.
There is a valve inside that can become 'sticky' if it gets too dirty, hence causing a rough idle. The idea is to remove the dirt and free the mechanism.

Tool Requirements
Not much is needed in the way of tools, three simple items will do:
1. Flat head screwdriver (to undo hoseclamp)
2. Some Spray Carb cleaner (widely available)
3. A Clean Rag

Time and Difficulty
This job is a 1 on a scale of 1-10 difficulty wise, it took a muppet like me five minutes.

Locating the I.C.V
First thing to do is know where the damn thing is... If you look at the picture there is a big rivetted hose and the I.C.V is the piece coming off this to the left.
http://img33.picoodle.com/img/img33/4/4/20/f_Icv1m_56e10d4.jpg
click
Removing the I.C.V
To remove it the first thing you need to do is disconnect the electrical connector- it is secured with a thin peice of metal... Put the screwdriver underneath and prize it up but make sure you have hold of it with your other hand incase it pings off and you lose it!
click
Once you have this off you can simply pull off the connector. I didn't disconnect the battery for this but if it makes you more comfortable
then do it.

Now you need to look at the best way to get the thing off. There are three problems... 1 - The rubber band type item securing it to the metal
seat. 2 - the hose coming from below the I.C.V and 3 - The join between the I.C.V and the large air hose. I went for the join between the I.C.V and the large air hose first by pulling the I.C.V towards the firewall and slightly twisting as I done it. I managed to get it out that end...
http://img33.picoodle.com/img/img33/4/4/20/f_Icv3m_d50bbf3.jpg
click
Then I undone the hoseclamp underneath and pulled that hose off downwards... This is hard to do, but prying with the screwdriver helps.
Just be careful not to damage the hose as you do it.

Once this is off you can actually remove the rubber band by getting the screwdriver between it and the metal peice it attaches to and prying it off. The I.C.V can then be removed.
http://img27.picoodle.com/img/img27/4/4/20/f_Icv5m_52c8416.jpg
click
Cleaning the I.C.V
Once the I.C.V is off it is easy to clean... Get the Carb cleaner (with the straw on the end if you have one and spray it into each hole... If its
anything like mine you will be amazed at how much dirty liquid comes out! When you're happy dry it off with a rag.

Re-fitting the I.C.V
Re-fitting is of course the reverse of removal. I found it easiest to get the bottom hose on first and then plug the side into the big air pipe,
then put the rubber band on. To get the rubber band on it is necessary to hook the side furthest away from you in first, then push your side in
with the end of the screwdriver. This is hard to explain but when you are doing it you will see what I mean. Obviously reconnect the electrical connector and the clip and see if it makes any difference... Even if it doesn't its a good preventative measure!

Text and pics by E34.535i.sport,
1990 BMW 535i Sport 146k
posted on bimmernut forums

E32 750iL 11/88, E32 750iL Highline 03/90
7 series Tech tips
http://tinyurl.com/3486c

• Idle Control Valve (ICV): Removal, Cleaning & Refitting (url) - shogun 2008-04-21 08:35:55 (1292 views)