Water in brake booster...car runs really rough..Help

[Trinie39]

Took my car to the car wash this morning n when i came out my car started running rough and stalling n puffung white smoke. Limped the car back to my house which is about a minute away and took out the cabin air stuff....there was a bunch of water down there. Was looking for a drain plug but didnt find it. I just used rags to sap up the water. What do i do next? Im scared ill hydro lock my motor if i start it. Car is an 01 530i/5

[Mach540]

There is a hole down there....... (TWSS)........... Keep looking.
Should be just fine after the water is out. It takes a lot of water to hydro-lock an engine. Ok, technically it only takes 55 mL of water, but that has to be directly applied to a single cylinder. Ain't no way that much is getting thru the vacuum lines, into the intake manifold, up into the intake runners, over to the other side of the intake, and thru the intake valves.........

[Trinie39]

I just went outside n fired it up n it ran good with an occasional misfire but there is still a bit of white smoke tho. Its been raining all evening so imma keep an eye on that water for sure this time. Tomorrow ill try to find that drain and look into replacing that booster

[JimLev]

Pretty sure there are 2 drain holes. Look under the the master cylinder towards the engine.

[Trinie39]

So started it just now n let it warm up. It ran ok until i revved it up n then it stalled. It turns over but it doesnt start and it puffs smoke when i turn it over. Is there a way to drain the booster without taking it out?

[gmak]

You are risking hydrolock - although given that you've run the engine a bit, you might be safe.

You can never get all the water out of the brake booster itself. That is where water is entering the engine and leading to the symptoms you are experiencing. In fact, given your location, you will likely lose the power boost as the diaphragm in the brake booster freezes.

I had this issue when the small hole in the bottom of the compartment was blocked by one of those helicopter seeds while I was in the car wash. I was lucky and did not experience hydro-lock of the engine. I ordered an inexpensive brake booster that turned out to be a Luk (OEM) and replacement was fairly simple.

That is probably your best recourse.

[Sewciu]

Good advice above. I just want to add that you should make sure your cabin filter holder gets replaced correctly. I believe there should be an overlap between it and the drainage channel near the hood strut. Not really sure how to describe it correctly maybe someone else can chime in. Basically water needs to drain properly and if your cabin filter holder gets put back incorrectly you'll get water in the booster cavity. This happened to me a few months ago; misfires and white smoke, broken booster (was on its way out anyway). Car has been alright since, not sure about any permanent damage though.
Good luck

[Trinie39]

I had this problem when i first got da car n had the brake pedal freeze on me. Took it to my mechanic n he got all the water out n its been fine until now. I do wash my car a lot so thats probably why i keep having this issue. Im going to mess with it tomorrow when i get off work n try to get that water out n take it to the repair shop. I cleaned the drain hole so the water should drain properly now. Will keep checking on it more regularly.

[JimLev]

Good advice above. I just want to add that you should make sure your cabin filter holder gets replaced correctly. I believe there should be an overlap between it and the drainage channel near the hood strut. Not really sure how to describe it correctly maybe someone else can chime in. Basically water needs to drain properly and if your cabin filter holder gets put back incorrectly you'll get water in the booster cavity.

Yes, the plastic part in the corner that is below the windshield (by the hood strut) needs to be on top of the cabin filter box, otherwise water will drain into the booster compartment.
Same for the other side too.

[wagons ho]

Took my car to the car wash this morning n when i came out my car started running rough and stalling n puffung white smoke. Limped the car back to my house which is about a minute away and took out the cabin air stuff....there was a bunch of water down there. Was looking for a drain plug but didnt find it. I just used rags to sap up the water. What do i do next? Im scared ill hydro lock my motor if i start it. Car is an 01 530i/5

I finally had to chime in. I know I'm a bit of a curmudgeon, but water is not getting in through the booster unless it won't hold vacuum and it's submerged.
The air intake for the booster is next to the rod from the brake pedal and takes air from the interior of the car.
Now a freezing or no boost pedal can be the sign of a internally bad booster, a leaking perimeter seal,(which could suck water) or a bad vacuum leak in a hose.
But a functional booster is not pulling water from under the hood. Keep looking and perform a cooling system pressure test.

[FelixEsq]

I had exactly this same problem.

You need to take everything related to your cabin air filter out on the driver's side. In my case, there was a nasty layer of rotten leaves at the bottom of the well underneath the brake booster. I dug that all out first.

Then I got a pick (really a piece of coat hanger bent 90 degrees at the end). You won't be able to see much, but under the brake booster, I found two holes that are more like slots or louvers cut into the bottom of the well. I used the pick to dig all the old rotten leaves out of those slots. After I did that, I took a pitcher of water and rinsed the little pieces out and made sure that the holes didn't re-clog with whatever detritus was left.

Satisfied the drains were clear, I put everything back, and it all ran fine again. I had no problems the rest of winter, despite having the rainiest year in my memory here in California. I now check in there every time I am digging around that part of the engine bay, just to make sure everything is clean.

[cmybimmer]

Didn't want to start a new thread since this one is relatively recent and I have the same problem..

Washed my car last night and lots of water entered the cabin/booster area. I was pretty much pulling out of the parking lot when my engine bogged after giving it a little gas. Immediately pulled over and shut the engine off. Thats when I realized water entered the engine. Total engine running time must not have been more than 30ish seconds (plus or minus).

After draining the compartment and the booster of water, and some minor inspection.. I saw that the water has reached inside the intake and DISA valve.

What are my options? I didn't want to risk running it some more so I towed it home last night. Will start more wrenching tonight and over the weekend with a friend. But just want to know what to expect and the proper procedure to resolve this issue.

Here is a more detailed write up of the incident: http://www.bimmerfest.com/forums/sho....php?t=1261456

[jclausen]

You might have hydrolocked your engine we just replace an engine number 6 rod bent

[computiNATEor]

Put it back together, start it up and let it warm up to get the water out of the engine. It'll take a bit for the water to evaporate. It's too late if it's already forked.

[vinyldude]

Before another attempt to start the engine, remove all spark plugs and run the starter for some time to get any possible water out of the combustion chambers. After that I think you could run it. Fix the drains so it won't happen again.

[jclausen]

After a puff of white smoke, a lot of it, a very strange mechanical sound, that was it. The rod was bent you could not even turn the engine over by hand.

[cmybimmer]

The car is up and running again. Thanks for the suggestions/advice!

[Kertis]

Had the same issue after buying my e39 about 2 months ago... took me 3 weeks to find out that my brake booster was full of water due to it being blocked. Meanwhile my engine was running with water all the time, and by the time my mechanic found out, I'd bent a conrod
Car is now getting fixed as it took me 2 weeks to find a conrod to match my engine -_-... All this because of some leaves... Wish I'd seen this thread before D: