[JStang]

As I was driving home from work today in a thunderstorm / downpour, the roads were pretty flooded. I always stay in the middle of the road as the outside lanes tend to flood more. I was in about a foot of standing water when all of a sudden my my SES light came on and my car started misfiring badly.

Whenever the roads are flooded, I stress out because of my Stett CAI. Naturally, my first thought was that I ingested some water and I was hydro locking. I had read before that if you hydro lock, you will know it and the car would stop running on the spot.

That made me feel much better. The car misfired for a few more miles as I drove through more flooded streets when all of a sudden the SES light went away and The car started running fine.

I hooked up the AP to the OBD port and hade the following codes:

2AAF (fuel pump plausibility) which is always present
29CF (Misfire cylinder 3)
29D0 (Misfire cylinder 4)
29CC (Misfire several cylinders)
2C77 (Lambda probe behind catalytic converter, signal)
2C78 (O2 sensor after converter 2)

My guess is that an O2 sensor got submerged but that is just a guess. Anyone else care to speculate?

I will tell you one thing, I am seriously considering selling my Stett CAI and going DCI after this scare. With the flash floods we get in Florida, it just doesn't seem worth the risk and worrying.

[joec500]

I highly doubt it's your CAI that caused this. It's probably misfires caused by one of many issues, but not limited to (plugs, coilpacks, FuelPump, Injectors, carbon buildup). I have had this happen to me too (not the same weather conditions). Also could be a bad batch of gas.

[JStang]

Originally Posted by joec500

I highly doubt it's your CAI that caused this. It's probably misfires caused by one of many issues, but not limited to (plugs, coilpacks, FuelPump, Injectors, carbon buildup). I have had this happen to me too (not the same weather conditions). Also could be a bad batch of gas.

I don't think the intake caused it either. Trust me, the water had something to do with it.

[hemi to e90]

bad gas or you coils or your plugs

[joec500]

Damn, were you driving to the point where your exhaust was under water? Assuming you were on the throttle the entire time I assume the the exhaust gas would prevent water from entering?

[ErvGotti]

Wait for everything to dry out, then go WOT. If you get the codes again then it's a hardware issue ie plugs, coils, ect. If you don't get any codes you might want to consider replacing your CAI. Almost every one on these boards get codes going WOT, and I doubt cruising along in rain would throw so many misfire codes.

Not to bash on Stett as I think they're an awesome company and they have done much for the N54 platform, but I've never been a fan of their CAI. It has one source of incoming air that is routed to the bottom of the bumper. I'd be nervous in heavy rain.

I've seen other platforms first hand that have hydro locked due to having one source of air in the lower bumper, though they we're not turbo charged (supercharged) and N/A. But IMHO would you want water hitting the hot blades of a turbo.

[F80M]

Dang...we gonna need some more crappy phone pictures...

Cant you convert Stett CAI to short ram version?

[wtfmateim65]

If you're in Florida please take that CAI out!! My cousin lived there for 2 years and I had put a CAI on his Scion tC which reached into the fender well. Insane flash flood hit and he could see it completely flooded with cars stopping in the freeway ahead so he took the only available exit, welp that exit really FLASH flooded and the exit lead down into a pond at the stoplight basically so him and 20ish other cars got instantly buoyant in the feet of water and hydrolocked, engine was toast!

[JStang]

Originally Posted by hemi to e90

bad gas or you coils or your plugs

No, no, and no.

[JStang]

Originally Posted by joec500

Damn, were you driving to the point where your exhaust was under water? Assuming you were on the throttle the entire time I assume the the exhaust gas would prevent water from entering?

I am thinking this is what happened. I never let off the throttle.

[JStang]

Originally Posted by wtfmateim65

If you're in Florida please take that CAI out!! My cousin lived there for 2 years and I had put a CAI on his Scion tC which reached into the fender well. Insane flash flood hit and he could see it completely flooded with cars stopping in the freeway ahead so he took the only available exit, welp that exit really FLASH flooded and the exit lead down into a pond at the stoplight basically so him and 20ish other cars got instantly buoyant in the feet of water and hydrolocked, engine was toast!

Yeah it's dci time. It's just not worth it.

[Eleventeen]

I don't think you'd suddenly get misfires on several cylinders that happened to clear up a few minutes later, if it was bad plugs/coils. That usually starts out with one cylinder under high load, then gets progressively worse as time goes on (days, weeks, months). It definitely sounds like you ingested some water to me. It's not like meth injection where it is being atomized by a nozzle under high pressure. If you get a splash of water into the filter, it can/will easily cause misfires across several cylinders. A big enough gulp and you could hydrolock, but anything less than that can easily cause temporary misfires.

[JStang]

Originally Posted by Eleventeen

I don't think you'd suddenly get misfires on several cylinders that happened to clear up a few minutes later, if it was bad plugs/coils. That usually starts out with one cylinder under high load, then gets progressively worse as time goes on (days, weeks, months). It definitely sounds like you ingested some water to me. It's not like meth injection where it is being atomized by a nozzle under high pressure. If you get a splash of water into the filter, it can/will easily cause misfires across several cylinders. A big enough gulp and you could hydrolock, but anything less than that can easily cause temporary misfires.

DCI is on order. I'm done stressing when it rains over a few degrees of cooler IAT's.

[NoQuarter]

When I am driving around in routine sort of traffic, my IAT is about 18-22 degF hotter than outside air temp with my DCI.

[BoostedE90]

Still pretty interested to know what happened cause I live in the same area and flooding these past few days has gotten ridiculous. I don't have a CIA but an area of concern is the 02 sensors.

I would think that would have been one heck of a gulp of water to cause some quench. It would have to come in through the CIA, through a turbo (or both), to the IC piping, through the IC, through the CP, and then finally into the intake manifold. But then again the engine is really designed to handle water so any amount of water ingested could be harmful.