Vacuum Leak question

[clindahl]

1989 BMW 525i Automatic

I got a check engine light yesterday and got a code of 1222, which is lambda control 1 (oxygen sensor). The oxygen sensor along with quite a few other parts on the car are new. I'm thinking I have a vaccum leak somewhere as quite a a few other posts point to a vaccum leak. I replaced the intake gaskets when chaning out other parts a while back. Some of the things I didn't change are listed on this REALOEM drawing -

http://www.realoem.com/bmw/showparts...61&hg=11&fg=45

My question is Part #2, on my car has a small hole in it and sucks air into the side of it. Since this part is original and never appears to have been changed, is this normal, or is this my vaccum leak and should be changed? The hole is about the size of the tip of a pen, but makes a difference in the idle when I put my thumb over it. Thoughts?

Also Part One of the parts marked #4 has a crack in it which I need to replace, but it's not as obviously wrong as #2.

Thanks

[genphreak]

If it has a hole in Part #2 it is because a sealed pipe has got brittle and snapped off or because the hole used to be otherwise covered by a grommet. Seal it and be happy every after. HOwever I doubt this is a big enough leak to cause a lambda error...

[Ferret]

If it has a hole in Part #2 it is because a sealed pipe has got brittle and snapped off or because the hole used to be otherwise covered by a grommet. Seal it and be happy every after. HOwever I doubt this is a big enough leak to cause a lambda error...

It /might/ throw a CEL if you rev the engine and the vaccuum inertia forces more air through that hole than it should do on returning to idle...?

Also... are your brakes working properly with a hole there?

[clindahl]

I used some carb cleaner and sprayed around to find the source of my vacuum leak. From what I can tell if I spray under the throttle body where the red arrow is I can raise the engine RPM. The only thing I can see under there is the EVAP canister purge solenoid connected to the intake. The thing circled in green is what has a small hole in the side, and if you click on the two links below they are closer up pictures of each item. Any thoughts?

And the brakes work fine

http://www.thelindahls.com/users/carl/bmw/bmw1.jpg

http://www.thelindahls.com/users/carl/bmw/bmw3.jpg

[pong]

if its d hole in d green thing that u circled... mine has that too...

the thing is... i have a vacuum leak too...

the funny part is i couldnt find it...
mine is idling rough and that small hole...

when i plug it with my hand...
nothing happens...

[clindahl]

Interisting. Good to know my car isn't the only one that has a little hole in that part.

I am convinced that there is a vaccum leak where the throttle position sensor on the bottom of the TB sits, or somewhere very close to that. This weekend I'm going to take the Throttle Body off and take a look around. The EVAP solenoid looks okay and is connected to it's vacuum source, I don't know what else is under there that could be leaking.

One thing that did help is a I replaced the breather hose from the valve cover to the Throttle Body (the PCV system?) and when I took the old hose off there wasn't a hose clamp on the TB side. I replaced it that way when I changed it a couple of months ago, and I recently noticed that it needs a clamp, both per realoem, and the fact that the rubber doesn't make a perfect seal so I put a hose clamp on there.

If you are looking for a vacuum leak to narrow it down, use carb cleaner. It really helped me narrow down what I was looking for.

[Robin-535im]

If you are looking for a vacuum leak to narrow it down, use carb cleaner. It really helped me narrow down what I was looking for.

Make sure you get the flammable carb cleaner. Last can I bought was the "safe" kind and was not flammable. Sprayed it right down the carb (on my truck) and not a dang thing happened.

"Don't worry, it's INflammable" - Dr. Nick

[clindahl]

related note, changing out some of the hoses that connect to the right two nipples on the throttle body and the brake booster.


Still chaning out hoses, and found that there was a vaccum leak under the throttle body, the evaporator solenoid for the carbon canister was loose, but I'm also going to pull the intake and change the O - Rings on the oil return tube for good measure, gaskets and O Rings were a total of $12.


The vacuum line from the brake booster up to that 2 into one valve was original for the car, had a MFG date of 12/88, which the car is a 1989. It was hard as a ROCK. No wonder it didn't seal to well!!

[clindahl]

So - I have done the following -


- Changed all hoses from Brake booster to throttle body.
- JB Welded the nipples on the trottle body back into place
- replaced the intake boot
- Pulled the intake and replaced the oil drain / vent tube O-Rings
- replaced intake gaskets
- pulled valve cover and did a valve adjustment
- pulled battery out for > 30 minutes

The car still gives a 1222 code, oxygen sensor. I have a slight exhaust leak on the rear manifold either at the head, or where it bolts to the down pipe before the 02 sensor.

What else should I check? I sprayed the entire engine bay w/ carb cleaner (yes the flamable kind) and no change in idle. Could the exhaust leak cause rough running and the 1222 code?

[genphreak]

So - I have done the following -


- Changed all hoses from Brake booster to throttle body.
- JB Welded the nipples on the trottle body back into place
- replaced the intake boot
- Pulled the intake and replaced the oil drain / vent tube O-Rings
- replaced intake gaskets
- pulled valve cover and did a valve adjustment
- pulled battery out for > 30 minutes

The car still gives a 1222 code, oxygen sensor. I have a slight exhaust leak on the rear manifold either at the head, or where it bolts to the down pipe before the 02 sensor.

What else should I check? I sprayed the entire engine bay w/ carb cleaner (yes the flamable kind) and no change in idle. Could the exhaust leak cause rough running and the 1222 code?

BTW, Be careful with Cary cleaner- it can damage rubber and seals etc...

Fix the exhaust leak as it can bring on an oxy sensor error and is a bad thing anyhow.

But a new sensor is cheap too.
http://cgi.ebay.com/ebaymotors/75-06...hippingPayment

nick