[pallymore]

2013 F30 335ix sedan

I got stuck in stand still traffic on a narrow road last Thursday, storm rolled in and water rose quickly around me. I had no choice but drove through some puddles (very slowly of course, following a few sedans and suvs in front of me) - there were some on coming traffic as well one of the big suvs on the other side were being stupid and splashing everyone.
I couldn't tell how deep the water was - but definitely below the bottom of the doors.

However the car went into limp mode and it started vibrating strongly. Check engine light came up with a message something like "drivetrain malfunction, ... maximum output not available."
I think it was because the engine was misfiring. I managed to reach a higher ground and after the traffic kinda cleared I found a parking spot on the side of the road so I stopped.

I opened the hood when the rain stopped - I saw a few pipes were wet - but overall i couldn't tell if there were any major damage. It started raining again so I closed the hood and went back in the car.

I waited for about ~30mins when the rain slowly went away, then I started the car again - it was still vibrating somewhat but I think it was much improved. Also the check engine light went away - the RPM was still slightly higher than normal though and I can tell the car wasn't able to accelerate like before (and with a noticeable lag).

Finally got home and parked the car in the garage, there were some white "smoke" coming from the hood - I assumed it was vaporized water.

Didn't try to drive the car on Friday as I was super busy - then yesterday I popped the hood and tried to assess if any damage was done.

The good news is the engine bay seems to be reasonably dry - however when I opened the air filter housing I noticed the filter is damp (like 80% damp - there are some small dry parts still) - and there are a few water drops in the corner of the filter. under the filter there were some water & dirt. (pics below)

I ordered new filters online and plan on clean the housing under the filter. However I'm not sure if there is anything else I can check easily - should I try to drive it around and see if there are any issues after replacing the filter? Am I screwed?

------------

TLDR; I think some water splashed into the air filter and the engine wasn't able to breathe properly (thus the misfires).

Will replace the air filter this week (took the old one out already).

Need advice:

1. is there an easy way to clean the air filter housing?
2. anything else I should replace ASAP?
3. anything else to look out for? (symptoms, etc)

I just moved to NY/NJ area and I'm still looking for a reliable mechanic - the next oil service is due soon and I plan on flush the coolant as well - should I replace the spark plugs too? (just replaced them last year)

thanks!

---- Updated: July 14, 2021

after changing air filter
car started ok, but engine misfires when i try to go above 20-25mph
codes:

P0300
P0302
P0303
P0304
P0305

I restarted the car the check engine light went away
no smoke coming out from the tailpipes (only some water droplets)
no visible leakage
oil temp stabilized around ~230F

[BimR]

I was stuck in NJ floods too cpl days ago. Check for codes first. My concern would be wet electronics honestly. Any dampness in car? Like when you enter, does the car smell damp?

As for mechanic suggestions, ask the NJ group for options based on where you are.

[pallymore]

Originally Posted by BimR

I was stuck in NJ floods too cpl days ago. Check for codes first. My concern would be wet electronics honestly. Any dampness in car? Like when you enter, does the car smell damp?

As for mechanic suggestions, ask the NJ group for options based on where you are.

Thanks

I don't think the interior smells any different TBH. I did try to feel the carpets around the doors with my hands and they all seem to be reasonably dry. but I will pay more attention to that next time.

Yea electronics are my concern as well however I'm not sure if there is anything I can do at this point.

[CajunBMW]

I can't tell you about your car without knowing exactly what happened but I can tell you the worst case scenario of what can happen if substantial amounts of water enter the air filter and pass through. Unfortunately you hydrolock your engine and ruin it.

My old e46 was a great car and ran great for 140ish K miles. I would have kept it. My wife was caught in a Louisiana deluge when she was driving home from shopping. She did not realize that a storm drain backed up (was clogged) on a regular road she usually drove on. Thus the water was higher than expected (maybe 12-14 inches???). Substantial amounts of water entered the air intake, flushed through the air filter (it was definitely wet) and went into the engine. The car was ruined and we had to make an insurance claim. We took the insurance payout and that was part of my down payment of my 2018 340 I bought a few years ago.

The net result is the water doesn't compress in the engine and something has to give. I could have seen about buying an e46 330 used engine, but really it was time for a new car after 15 years. Hopefully this worst case scenario does not play out for you.

Good luck.

[CajunBMW]

Originally Posted by pallymore

Thanks

I don't think the interior smells any different TBH. I did try to feel the carpets around the doors with my hands and they all seem to be reasonably dry. but I will pay more attention to that next time.

Yea electronics are my concern as well however I'm not sure if there is anything I can do at this point.

The electronics are usually pretty well sealed, although as cars get older this could be an issue. As I pointed out above, the issue I worry about now is hydrolocking your engine. The manual lists 9.5 or something like that inches as the max you should drive through, but really it is lots of water in the air intake unless you drive in really deep water that should be an issue.

[pallymore]

Originally Posted by CajunBMW

I can't tell you about your car without knowing exactly what happened but I can tell you the worst case scenario of what can happen if substantial amounts of water enter the air filter and pass through. Unfortunately you hydrolock your engine and ruin it.

My old e46 was a great car and ran great for 140ish K miles. I would have kept it. My wife was caught in a Louisiana deluge when she was driving home from shopping. She did not realize that a storm drain backed up (was clogged) on a regular road she usually drove on. Thus the water was higher than expected (maybe 12-14 inches???). Substantial amounts of water entered the air intake, flushed through the air filter (it was definitely wet) and went into the engine. The car was ruined and we had to make an insurance claim. We took the insurance payout and that was part of my down payment of my 2018 340 I bought a few years ago.

The net result is the water doesn't compress in the engine and something has to give. I could have seen about buying an e46 330 used engine, but really it was time for a new car after 15 years. Hopefully this worst case scenario does not play out for you.

Good luck.

Thanks - yea I'm aware of hydrolocking but I think I might be ok? The engine didn't stall or making weird noises, and I made it home after driving ~3 miles. the car did start 2-3 times without engine misfiring / vibration since then �� also it sounded normal when I started it yesterday but at the same time I'm not really an expert on this topic.

fingers crossed ������������

[Billfitz]

If you hydrolocked the car would be DOA. Never even think about going through water, because the air intake is down low on the front of the car at the same level as the fog lamps. If you're stuck in water turn the engine off. Worst case open the hood, remove the top of the intake cover, then close the hood. That way you bypass the intake and filter.

[Desertnate]

Originally Posted by Billfitz

If you hydrolocked the car would be DOA. Never even think about going through water, because the air intake is down low on the front of the car at the same level as the fog lamps.

Does this differ between the F30 and F32 or maybe N vs B gen engines? On my F32, the air intake is in the upper portion of the right kidney grill. That's about level with my headlights; and higher than the fog lights (or where they would be if I didn't have the THP).

I've heard comments like yours before and it worried me, but when looking at RealOEM there isn't any ducting pulling air from a lower portion of the car below the spot in the kidney grill https://www.realoem.com/bmw/enUS/sho...diagId=13_1499

Regardless, the kidney grills are pretty low to the ground when facing a badly flooded street and I could see a bow wave from a large truck washing over the hood/bumper area of a car causing it to ingest water and hydro lock.

[pallymore]

Originally Posted by Desertnate

Does this differ between the F30 and F32 or maybe N vs B gen engines? On my F32, the air intake is in the upper portion of the right kidney grill. That's about level with my headlights; and higher than the fog lights (or where they would be if I didn't have the THP).

I've heard comments like yours before and it worried me, but when looking at RealOEM there isn't any ducting pulling air from a lower portion of the car below the spot in the kidney grill https://www.realoem.com/bmw/enUS/sho...diagId=13_1499

Regardless, the kidney grills are pretty low to the ground when facing a badly flooded street and I could see a bow wave from a large truck washing over the hood/bumper area of a car causing it to ingest water and hydro lock.

Yea - the intake is inside the kidney grills (closer to the top) (i have M sport package but I don't think that changes anything)

I think if there was enough water to hydrolock the engine then the car was probably already dead - my theory is some water got to the air filters but probably not much got through (since the filter was still partially dry) - the wet filter limits the air flow :/

anyways - new filters should arrive this week.

[auburnf30x]

You'd know if you hydrolocked - the car would have very abruptly shut off, and you'd never get it started again. Most likely wouldn't even turn over. Back in the days of cast iron, the thing to do was remove the spark plugs and slowly crank the engine to get the water out. Let things dry, put the plugs back in, and hope for the best.

These days, with materials used, hydrolock spells almost certain total engine destruction.

To me, it sounds like your car ingested some water. Not enough to lock the engine but enough to possibly contaminate the fuel/air mixture and cause misfires, either by interfering with the MAF sensor operation, large concentrations of water vapor entering the combustion chamber, or both. I'd start by pulling codes to see how many systems were affected.

[Billfitz]

Yeah, my intake isn't that low, but it is lower than the headlights. Any wave high enough to enter the right grille would be high enough to enter the intake. The duct has a drain to allow an out for the moderate amount of water that a heavy rain would put in there, but not the kind of wave that you'll get hit with when you're in a foot of water and a truck passes by.

[Wires]

If I was to guess, you sucked some water into the intake box, plugged the filter (IE it got wet) and just snuffed out the engine do to low air flow.

Better that than an actually hydro-lock! Water doesn't compress like air, so bad things happen.

[CajunBMW]

Originally Posted by Billfitz

Yeah, my intake isn't that low, but it is lower than the headlights. Any wave high enough to enter the right grille would be high enough to enter the intake. The duct has a drain to allow an out for the moderate amount of water that a heavy rain would put in there, but not the kind of wave that you'll get hit with when you're in a foot of water and a truck passes by.

That is exactly what happened in my story above. A large truck sped by causing a huge wave to hit my e46. The car died pretty quickly. It did turn over when dried but there was nothing left in the cylinders due to the damaged parts. The compression was low as you can imagine on all 6 of the cylinders. It was a good lesson learned. We are all very careful about water now, especially my wife.

[CajunBMW]

Originally Posted by Wires

If I was to guess, you sucked some water into the intake box, plugged the filter (IE it got wet) and just snuffed out the engine do to low air flow.

Better that than an actually hydro-lock! Water doesn't compress like air, so bad things happen.

I certainly wish that is what happened to my car….but alas the filter was like a sponge soaked in a bucket of water. The car took in so much water there was nothing that could prevent hydrolocking of the engine.

As a funny story, my brother in law wanted to give my wife a ruler with the BMW manual 9.6" high water point marked so that when ever in doubt, she could pull out the ruler and test the water….she told him she had a better place to use it and thus he decided it was safer not to give her the ruler.

Joking aside that incident certainly taught us all to be more careful during southern deluges and to make sure either A) you park the car until the water goes down or B) take a different routes. But honestly sometimes when you are out driving and it is raining like crazy it is hard to know if a storm drain clogs or if near construction if something is causing abnormal low points in the road.

[pallymore]

Originally Posted by Wires

If I was to guess, you sucked some water into the intake box, plugged the filter (IE it got wet) and just snuffed out the engine do to low air flow.

Better that than an actually hydro-lock! Water doesn't compress like air, so bad things happen.

I sure hope that was the case - the engine sounded normal when I started it on Saturday - and it was idling at ~700-800ish RPM. It wasn't shaking/vibrating anymore so I think that might be a good sign.

Originally Posted by auburnf30x

You'd know if you hydrolocked - the car would have very abruptly shut off, and you'd never get it started again. Most likely wouldn't even turn over. Back in the days of cast iron, the thing to do was remove the spark plugs and slowly crank the engine to get the water out. Let things dry, put the plugs back in, and hope for the best.

These days, with materials used, hydrolock spells almost certain total engine destruction.

To me, it sounds like your car ingested some water. Not enough to lock the engine but enough to possibly contaminate the fuel/air mixture and cause misfires, either by interfering with the MAF sensor operation, large concentrations of water vapor entering the combustion chamber, or both. I'd start by pulling codes to see how many systems were affected.

Yea that's what I thought - I borrowed a code reader and plan on doing that when the air filter arrives. The check engine light went off already though - will see if I can still see some of the past codes.

Originally Posted by CajunBMW

I certainly wish that is what happened to my car….but alas the filter was like a sponge soaked in a bucket of water. The car took in so much water there was nothing that could prevent hydrolocking of the engine.

As a funny story, my brother in law wanted to give my wife a ruler with the BMW manual 9.6" high water point marked so that when ever in doubt, she could pull out the ruler and test the water….she told him she had a better place to use it and thus he decided it was safer not to give her the ruler.

Joking aside that incident certainly taught us all to be more careful during southern deluges and to make sure either A) you park the car until the water goes down or B) take a different routes. But honestly sometimes when you are out driving and it is raining like crazy it is hard to know if a storm drain clogs or if near construction if something is causing abnormal low points in the road.

Yea I've learned my lesson as well
stopping wasn't a real option for me - it's a narrow road with no spaces to park on the side, and I was already sitting in that traffic for a long time. I decided not to stop in the middle of the road and blocking everyone for unknown amount of time (who knows when the rain was gonna stop - maybe the water would have gotten even higher if the traffic jam lasted longer)
anyways - I probably am gonna check weather report carefully every time before I go out now

[F30lolz]

I’m sure you’ll be fine OP. I’ve mentioned this many times before but I got caught in a flash flood December 2019 right after I got the updated TC/guides done at N/C by South Motors BMW in Miami. Hydrolocked engine and didn’t have the car for about 4 weeks. Insurance got me a replacement engine and a little over 100k miles on said engine, I’m doing OK so far.

[Rockinryan2424]

Originally Posted by pallymore

2013 F30 335ix sedan

I got stuck in stand still traffic on a narrow road last Thursday, storm rolled in and water rose quickly around me. I had no choice but drove through some puddles (very slowly of course, following a few sedans and suvs in front of me) - there were some on coming traffic as well one of the big suvs on the other side were being stupid and splashing everyone.
I couldn't tell how deep the water was - but definitely below the bottom of the doors.

However the car went into limp mode and it started vibrating strongly. Check engine light came up with a message something like "drivetrain malfunction, ... maximum output not available."
I think it was because the engine was misfiring. I managed to reach a higher ground and after the traffic kinda cleared I found a parking spot on the side of the road so I stopped.

I opened the hood when the rain stopped - I saw a few pipes were wet - but overall i couldn't tell if there were any major damage. It started raining again so I closed the hood and went back in the car.

I waited for about ~30mins when the rain slowly went away, then I started the car again - it was still vibrating somewhat but I think it was much improved. Also the check engine light went away - the RPM was still slightly higher than normal though and I can tell the car wasn't able to accelerate like before (and with a noticeable lag).

Finally got home and parked the car in the garage, there were some white "smoke" coming from the hood - I assumed it was vaporized water.

Didn't try to drive the car on Friday as I was super busy - then yesterday I popped the hood and tried to assess if any damage was done.

The good news is the engine bay seems to be reasonably dry - however when I opened the air filter housing I noticed the filter is damp (like 80% damp - there are some small dry parts still) - and there are a few water drops in the corner of the filter. under the filter there were some water & dirt. (pics below)

I ordered new filters online and plan on clean the housing under the filter. However I'm not sure if there is anything else I can check easily - should I try to drive it around and see if there are any issues after replacing the filter? Am I screwed?

------------

TLDR; I think some water splashed into the air filter and the engine wasn't able to breathe properly (thus the misfires).

Will replace the air filter this week (took the old one out already).

Need advice:

1. is there an easy way to clean the air filter housing?
2. anything else I should replace ASAP?
3. anything else to look out for? (symptoms, etc)

I just moved to NY/NJ area and I'm still looking for a reliable mechanic - the next oil service is due soon and I plan on flush the coolant as well - should I replace the spark plugs too? (just replaced them last year)

thanks!

Huge bowl of rice should work

[pallymore]

Originally Posted by F30lolz

I’m sure you’ll be fine OP. I’ve mentioned this many times before but I got caught in a flash flood December 2019 right after I got the updated TC/guides done at N/C by South Motors BMW in Miami. Hydrolocked engine and didn’t have the car for about 4 weeks. Insurance got me a replacement engine and a little over 100k miles on said engine, I’m doing OK so far.

Thanks - I'm hoping for the best here, the air filter is gonna arrive tomorrow, and my code reader is ready

Originally Posted by Rockinryan2424

Huge bowl of rice should work

[dmaxdmax]

...and next time that happens accidentally, I'd consider driving it longer afterward and drying things out. Water could pop into your exhaust...and a hot engine can do a lot of drying for things like connections.

Finally, since flood water isn't particularly clean, I'd rinse things off well...beginning with the condenser/radiator and everything underneath.

As an aside, I love gummi pflege to treat gaskets...and Techron to treat the fuel system...and when you treat the car, it'll treat you back.

[pallymore]

sad, sad day.

the filter arrived - i replaced it and cleaned the air filter housing with paper towels & vacuum.

the car started smoothly - I couldn't hear any odd sound or anything abnormal from the engine block so i decided to take it out to the road. not long after exiting the garage I noticed the car doesn't accelerate as fast as I could remember (i was driving at low speeds though) - I turned onto a uphill road and gave it a bit more gas - and then it started misfiring again it's a bit weird because the check engine light flashed on and off a couple of times.

pulled to the side and got the codes:

P0300
P0302
P0303
P0304
P0305

so I think cylinder 2,3,4,5 were all misfiring - this is not good.

I restarted the car (the check engine light went away) and got back home at low speeds.

I let it idle for a bit and it all seemed & sounded normal (even when I revved to ~3k rpm).

no smoke coming out from the tailpipes (only some water droplets I guess that's normal)
no leakage
oil temp stabilized around ~230F


I'm definitely gonna take it to a mechanic soon-ish.
I think I might want to replace all the spark plugs and flush the oil - anything I should be looking out for when talking to the mechanic?

[BimR]

Originally Posted by pallymore

sad, sad day.

the filter arrived - i replaced it and cleaned the air filter housing with paper towels & vacuum.

the car started smoothly - I couldn't hear any odd sound or anything abnormal from the engine block so i decided to take it out to the road. not long after exiting the garage I noticed the car doesn't accelerate as fast as I could remember (i was driving at low speeds though) - I turned onto a uphill road and gave it a bit more gas - and then it started misfiring again it's a bit weird because the check engine light flashed on and off a couple of times.

pulled to the side and got the codes:

P0300
P0302
P0303
P0304
P0305

so I think cylinder 2,3,4,5 were all misfiring - this is not good.

I restarted the car (the check engine light went away) and got back home at low speeds.

I let it idle for a bit and it all seemed & sounded normal (even when I revved to ~3k rpm).

no smoke coming out from the tailpipes (only some water droplets I guess that's normal)
no leakage
oil temp stabilized around ~230F


I'm definitely gonna take it to a mechanic soon-ish.
I think I might want to replace all the spark plugs and flush the oil - anything I should be looking out for when talking to the mechanic?

Oh I'm sorry man. But it could be as simple as spark plugs. Those aren't very difficult to replace yourself but a mechanic can do that quick. Start there and hope for the best.

[pallymore]

Originally Posted by BimR

Oh I'm sorry man. But it could be as simple as spark plugs. Those aren't very difficult to replace yourself but a mechanic can do that quick. Start there and hope for the best.

thanks - yea I don't really have any tools will ask the mechanic to replace those for me and hopefully that'll just fix the thing