Identifying vacuum leak. Help please.

[Erick]

Hey guys.

I'm out of town for 2 weeks but I'm still trying to figure out where could this "vacuum leak" in my car be.

I know my car gets worse everytime I crank it.... so it's been sitting in my garage for a good while now.

I took off the intake boot and cleaned it.... yet I still couldn't find any cracks. If anyone here ever had a cracked intake boot, was the crack easily noticable? I was looking through each bend and I still couldnt find anything. I'm starting to doubt it could even be that.

When I get back I'm going to check for maybe some stuck flap in the AFM or the air filter, but I really dont have any other ideas of what could it be.

Any ideas would be helpful. By the way Charlie, I pulled the valve cover off that day and none of the rocker arms seem damaged. No cracks or nothing out of place..... at least in my understanding they are all normal.

Erick

[rwh11385]

You definately cannot see a crack in the intake boot. You'd have to spray carb cleaner on the boot while the car is running. If the car runs smoother, you got a leak.

Or, just buy a new one - they're like $10. Cheap peace of mind.

Most likely it is the intake boot, culprit 10-1 times.

[nando]

I could see the cracks in my intake boot.. in fact, on the bottom it cracked so badly that there was a dime sized hole. I cleaned it with alcohol and repaired it with sillicone sealant (black) and it's fine now. Eventually I suppose I'll replace it but it works fine for now.

[Erick]

Alright I'm going to pay 10 bucks for shits and giggles and get one. If it isnt that I'll just put one of them on eBay and keep hunting for the next probable cause.

[Mystikal]

Ha, my intake boot had a tear in a joint about an inch long. I had foil tape holding it together, finally decided to pick a new one up today and put it on.

[Erick]

was the car drivable before though?

[Mystikal]

Yeah, the idle was just iffy. No matter how well I taped it there was air escaping, because now that I put the new boot on there is a huge difference just off idle in performance.

[Erick]

Ok so I just replaced my intake boot with a brand new one.

Guess what? That's not it. :evil:

Now I have 3 days to the Winterblaze and my car is nowhere near drivable.

I'm considering taking it to a mechanic and try to beg for a good price....

Any ideas what it could be? Any last resort I might try?

Thanks

[KenC]

If you have a vacuum leak, it may not be coming from the intake boot. There are 3 or 4 different hoses it could be... or it may possibly be that your dipstick isnt tightly sealed. If I were you, I'd just throw down $30 or so dollars and get the entire set of hoses... I think that Bavarian Autosport has a set of them.

[Erick]

Fucking A..... and I need my car for this weekend :evil:

Is there any way I can trace this down to the problem? I really dont want any more "guesses"

Next thing you know I'll buy all those hoses, and it'll STILL do the same shit.

Any ideas how to narrow this down?

[BMW BMXER]

Butane. Spray some around if the idle goes up you found your leak.

[KenC]

Butane. Spray some around if the idle goes up you found your leak.

Or carb cleaner, as mentioned above. That'll let you know if you have a leak or not.

What led you to believe that there was a leak in the first place?

[Erick]

You guys and the Bentley. However the Bentley gave tons of different locations where the leak could be.

I checked the ones it said it would most likely be it. I havent had the time to check the others.... and the 02 sensor I can't swap on my own.

[skat 325is]

I recently replaced the o2 sensor and the icv and i still have a damn bad idle, intake boot is fine also,i replaced it last year, plus i've sprayed wd-40 on key areas where theyre might be vacuum leak and have'nt find anything. Im starting to think its the afm dying, i also have 2 ECUs, one chipped and one stock...still the same.

[peerless]

Re: Identifying vacuum leak. Help please.

" I'm still trying to figure out where could this "vacuum leak" in my car be.
I know my car gets worse everytime I crank it."

When you say it gets worse everytime you crank it, Does this mean it won't start?

Generally vacumn leaks remain the same, it either leaks or it don't. I suppose it could get worse over time. A car will still start with a vacuumn leak it will just idle like shit and want to die if the leak is big enough.

You need to specify more information to get accurate help.
Did this problem happen over time or all of the sudden?
Does the car start and run?