Engine/exhuasr/water problem

[PiercedTiger]

I know this isn't tacoma related, but since we have so many knowledgable people here I'm hoping someone may have an idea about this problem I'm having. I don't belong to any other auto forums that are this active so many you guys can chip in with some general ideas about what could be going on.

The problem:
My 98 corolla tends to stall whenever it rains enough to leave water standing on the road. It sounds like the engine has sucked in water and is trying to blow it out (stuttering, jerking, stalls as soon as I try to drive, or rpms just drop off). First time it happened I hitt a deep pothole I couldn't see under the water. It had at least 4" of water in it, and it was on the passenger side as I went around the corner. Second time I went through 1-2" max covering the entire intersection. The last time there was just enough to see the outline of standing water so maybe only 1/2 an inch on the passenger side (this seems to be a common item between them, water on the passenger side). Now, the intake is on the left side of the engine so I can't imagine it splashes up past then engine, bounces off the hood and down on the intake, or any other way around the engine/transmission. I've popped the hood after this happens a couple times and everything under the hood is DRY!

I had an exhaust leak at one point, but my mechanic said that wouldn't cause the problem.... Either way, I've had the leek fixed with a new gasket in the flange between the headers and exhaust, and had the entire exhaust system (cat, back to muffler) replaced maybe 6 months ago. Being so new I shouldn't have another hole already. I don't think I have a flex pipe (was thinking maybe water could get in that somehow), but will have to jack up the car to verify that.

I have a short-ram intake, but the filter is always dry (there's dust on it so I should see water marks or splash marks on the hood/engine/etc). Some of the splash guards have broken off, but those were under the front bumper/radiator so I don't think the protect much. I can get the car going by continually restarting it, and reving the engine until it idles normal so I know it's not completely hydro locker.


Any ideas how the water is getting in the engine? Or had a similar problem with another vehicle? It happened to my buddy's jeep a couple months back while offroading with water crossings and he has a snorkel, but I won't get into that here. Any ideas would be great. I need to figure this out without paying to leave it at the dealer/mechanic for a few days, or have my wife and kids get stranded somewhere.

[Ricky Bobby]

Maybe water/moisture is getting into your distributor.

[PiercedTiger]

It's all EFI so I don't have a distributor, or at least a cap with brushes and contacts. Thanks though! It also sounds like it's trying to push water out when I get on the gas. As in, I FLOORED it, and it was barely above idle and sounded like it was chokeing/coughing/misfiring. It's hard to explain.

[Sony]

It's very possible that the water is hitting some electrical wiring somehwere that has come unshieled and it shorting out your ignition system. This would cause the engine to studder and stall.

[PiercedTiger]

thanks. I'll see if I can check the wiring this weekend.

Would that make it sound like it's trying to blow water out the exhaust? The only thing I can think of that sorta explains the sound is a gurgling along with the stuttering/poping.

Also, the car fine the rest of the way home after I just sat at a couple redlights reving the engine... I could hear it clearing out. The idle became smoother, responded faster to the gas pedal, etc. Almost like how a person's breathing slows to normal after they spit out what they were choking on or trying to cough out.

[gdctaco]

I would say it has a misfire, and the water is shorting something out as mentioned. or maybe, maybe the water is splashed up onto the engine turned to steam and the damp steam sucked into your intake is enough to cause a misfire. I would check your spark plugs for proper gap and maybe a loose, or burnt lead. But It's definately an ignition thing and not pushign water out the exhaust, thats impossible. Water doesnt go through an engine, if water gets into your intake it destroys your engine, by getting into the cylinder and when the engine tries to compress water something has to give, like a connecting rod or worse the crankshaft. hope this helps.

[PiercedTiger]

ok thanks! Like i said, it sounds like a gurgling noise like water was being pushed out or something. I'm assuming water as it only happens when I drive through standing water. Rain, wet roads (without standing water), snow, etc never affect it. And the engine seems to run perfectly the rest of the time. I know a CEL came on when it was stalling. Unfortunately I was in traffic and didn't have my scangauge so I have no idea what it was. The CEL went out after the engine started running correctly so I have a feeling it's not stored either, but maybe I can check tonight just to see if it's still there.

[PiercedTiger]

Any other ideas?

[bardb]

Just because the CEL is out doesn't mean that the code is gone. Just like it sometimes takes several faults before the light is tripped, it takes several drive cycles without a fault for it to turn off the light and even more to clear it completely. It all depends on the fault and how the engineers wanted to keep a record of it.

[PiercedTiger]

Thanks. I need to remember to plug my scangauge in tonight to check on that. Maybe it'll give me an idea what's going on. It didn't throw a CEL the last few times it did it. Or maybe it did and I didn't have a code reader yet... I forget.

[PiercedTiger]

Ok, so I plugged my SG in finally, and it said it wasn't ready. I didn't clear any codes manually, but I KNOW I saw the CEL come one, kinda flash, and go off. Is it possible it reset itself? I drove it for a couple days and the light came back on and stayed on. It's a P0420 code. Something about the cat not being efficient. From what I can tell it could be a bad cat or bad 02 sensor. I had this code last summer, and had the exhaust replaced to fix it. I called a mechanic and he said if the engine was misfiring it could've dumped unburned fuel into the cat and threw that CEL. I reset it manually while the car is running right to see if it comes back again.

I also checked as many wires as I could reach and see under the hood. They all seem intact and shouldn't be grounding out.

Anyone have any idea what could be going on? I really can't afford to leave it at a shop for several days so they can go over everything to figure out (maybe!) what's causing this. The coil pack is on the driver side so it's opposite the side that hit any water this last time so I don't think that got wet.

I noticed the valve cover gasket looks a little worn and I was thinking about replacing that. Could water get in there? What looked like a bad section to me was right above the passenger side wheel too. I have no idea what condition the gasket is in, but the outter edge seems to be crumbling away. Is this even something to consider?

[Sony]

http://www.obd-codes.com/trouble_cod...old-bank-1.php

[Crowbar911]

Is it possible that water got up the exhuast a little from the back? that would cause a guugle sound.

Its highly unlikely, but possible

[PiercedTiger]

Sony: Thanks. I found the code earlier so I checked what I could based on that.


A code P0420 may mean that one or more of the following has happened:

• Leaded fuel was used where unleaded was called for
• An oxygen sensor is not reading (functioning) properly
• The engine coolant temperature sensor is not working properly
• Damaged exhaust manifold / catalytic converter / exhaust pipe
• Retarded spark timing

1. I only use unleaded gas (can you even buy leaded anymore?) from stations I frequent all the time without problems.
2-4. Seems like if any of the sensors are malfunctioning it would happen more often. Not just when I hit some standing water on the road. All the wires I could see seem intact and shouldn't be shorting out. Unless they somehow wore off the insulation, but not the factory tape/wrap around the entire bundle.
5. I suppose timing could be off and that may have caused the CEL when the engine was sputtering, but I don't know how to check that. And I don't know what would cause that when there's water on the road....

Crowbar911: That's what I was thinking. I had a small hole somewhere in the exhaust the first few times it happened. However, I now have a new muffler and new gasket in the flange between the cat and headers so everything SHOULD be sealed... I did a quick check of that today, but I want to jack up the car and get a better look at averything. Especially since it didn't happen as bad this time (after the exhaust was fixed). I was able to restart the engine immediatley even if it did sputter and lurch when I tried to drive. I was able to get going again much sooner than the most recent time this happened. Almost like not as much water got in. The previous time I hit 3-4" going through an intersection and it took maybe 15 minutes to get going again. And that was just trying to get the engine started and creep along until it ran normal. This last time I was able to pull onto another road, die at a red light, and by the second change continue on 2-3 minutes later, at most. People keep telling me this isn't possible tho! But at least you confirm my original idea. Most of the exhaust system is towards the passenger side, and that's where the water has been each time. I've thought about getting some exhaust wrap/tape and seeing if that helps. Think it would seal it up enough to stop splashes?

[Crowbar911]

I know nothing about exhaust systems, I am just starting to get into my car and learn.

You still have a hole in your exhaust, the opening at the back of the car where it comes out from. Could it have gone into that and messed with an 02 sensor and/or your cat converter?