Degraded Intake Boot - Cold start problems fixed!

After reading various post on how dirty the ICV could get, I decided to take a look at mine. While furiously working on removing the horribly positioned hose clamps on the throttle body intake boot, I noticed that the line that runs to to the ICV off of the main air intake was just hanging in there by a thread! This was really surprising to me partly because I expected the idle control valve to be responsible for the shoddy idling and also the car has just under 63,000 miles on it; A little low for the intake boot to be falling apart don't you think?





There was also a nice little tear right where the hose mated with the ICV which made removing the hose without tearing it in two a bit more difficult.





I started to figure out a way to patch this... After cleaning the boot down with heavy amounts of starting fluid ,I found some clear plastic hose laying around that is just the right diameter so that it is snug in side the line and also fits inside of the ICV as well... Score! There was also some braided hose laying around that might be a bit more crimp resistant and better for this application but sadly it was just a bit too small. I then cut the hose at an angle so that it was flush with the main intake part of the boot that leads to the throttle body.





And as a finishing touch... duct tape!





Needless to say this was an improvement. The car now starts right up when cold with out any low rpm dips and stalls that use to happen almost every time. The ICV turned out to be in excellent condition and rattled freely when shaken (I still gave it a nice brake cleaner bath). When it's all said and done; well worth the time and effort vs. driving around with a bad intake boot until a new one comes. If you're having bad idling problems you should defiantly take a look at your ICV and give it a good cleaning and who knows what you might find while you're in there!

By the way - I'm new here. Well sorta. Long time lurker, first time poster! I thought what better way to say "Hi" than to make a nice little write-up. Even if it was just about patching an intake boot!

Nice fix, but the replacement boot is like $11.

I know, the boot was just something I noticed while cleaning the ICV and looked like it needed to be fixed now. I'm really glad I did patch it up though and I'll be ordering a new one tonight; It's on my to-do list.

At least you taped it up for now. I hope you used my ICV vid

Originally Posted by Solidjake

At least you taped it up for now. I hope you used my ICV vid

Not exclusively but I definitely referenced it alot! Pretty good job explaining how to get that out.

Nice, thanks.

Get that new boot!

Will do! Not gonna let that sit in there for too much longer that's for sure

This was really surprising to me partly because I expected the idle control valve to be responsible for the shoddy idling and also the car has just under 63,000 miles on it; A little low for the intake boot to be falling apart don't you think?

The intake boot failure is not mileage dependent, it's time based, since the rubber dries out over time. If there was a silicon dressing applied to the hoses, it might prolong the life of these parts, but otherwise, it's just a sign of old age.

A valid point. I'm just glad I found that before it got worse or I started to blame other parts.

Nice gloves

Glad you got your car running good though. That piece is a serious wear item.

Originally Posted by Andy2108

Nice gloves

Hey, those gloves are great! Well... when they fit of course... which these ones don't

hahah why didnt you just buy a new one.. now you have to take it off twice and that thing is in a tight spot.

Originally Posted by luc

hahah why didnt you just buy a new one.. now you have to take it off twice and that thing is in a tight spot.

This has already been addressed. I wanted to patch it up while I was rooting around in there. I don't have a warehouse of OEM bimmer parts now do I? Don't worry though, a new one is on it's way soon.

Edit: Oh, and the practice taking off all those other parts is always nice too

Gotta do this too...

i think my intake boot is F*ed up as well. whistles like a teapot at high rpms.

Originally Posted by E46tknv

i think my intake boot is F*ed up as well. whistles like a teapot at high rpms.

If there are no visible cracks in the boot then make sure all the hose clamps are nice and tight and well seated. I found that smearing petroleum jelly on all of the mating parts makes installation a helluva lot easier and I'm sure it helps with keeping your intake sealed too.

i looked at all parts of the intake, but never inspected the one before the throttle body. too tight of a spot. I didnt want to bother taking it off, seeing holes, and putting it back on. once new one comes in, then ill check it out. But a few other fanatics gave me the same answer, that it is intake boot

Yeah it is pretty tight in there. In order to get a good look at it you'll have to remove a composite heat shield by the brake reservoir which can be tricky sometimes.

Plastics and rubber, the achilles heel of the modern car....nice find!