With all the rain we've been getting here in SoCal, I have been keeping a close eye on my car with the AEM v2 intake installed. It's normally garaged, but I had to go out of town for a few days and leave it parked outside at the airport, in addition to driving around in the rain for many days. I never entered any deep water (more than about 1 inch), but was worried just the same.

Sure enough, earlier this week, the car started cutting out and acting funny. I pulled my intake apart and found close to 1 cup of water just laying in the bottom tube. The rest of the intake piping was damp, with droplets of water all along from the bottom pipe clear up to the junction with the throttle body.

I believe the water is getting pulled in from the front grill during driving, probably during high RPM (VTEC) driving, which I commonly do merging onto freeways even in the rain. When I looked at the filter, it was noticeably dirty on the side that faces the front grill. I've plugged up all the drain holes around the hood that sit above the filter, and have not cut out my faux air ducts. The underside plastic has very few openings so I doubt significant water can splash up there - and my cuts around the intake tubing are all really tight.

I got it all dried out, changed my oil (which was uncharacteristically low due to bad behavior - read negligence - on my part), checked all my spark plugs, and (with the intake still disconnected) started up the car. Thankfully, it ran perfectly.

Knowing we had (have) more rain in the forecast, I debated my options. I could reinstall the stock airbox, reconnect the intake and somehow cover up the grill, or ... here's what I did:

I connected the top intake tube back to the throttle body and then installed the stock air filter on it. This seems like a great solution, because it's pretty easy and it keeps the air filter inside the engine bay (read dry). I duct taped the ends of the lower tube closed and zip tied everything in place.

Took it for a good drive yesterday and it's running perfectly, albeit not as perky as it is with the full intake connected, but it's DRY.

This may be a good workaround for anyone else worried about driving in the rain with their intakes and potential hydrolock.

 

Red, your solution is a good one and sound.
However, the water is getting in when you are parked in heavy rains. It comes from above via this hole:

Also, if you have a large gap between your headlight and the body panel, the water can get in that way.
Plug the hole with something (rubber bung, or 3M flim or duct tape) and get an "umbrella". You can either make one out of a plastic plant pot, used milk jug or buy one from these guys for big money:
http://www.cardomain.com/item/INJHS5000P

Driving slowly into a big pool of water will not suck up enough water to do damage as long as the filter is not totally submerged. Water is heavier than air and the air will go in first unless you rev it up. Any splashing that gets onto the filter while driving will get sucked through the filter and become a mist. The engine can handle this vaporized mist without a problem. This would be no different than an engine that has water injection installed on it. When I had the AEM, the filter was often soaking wet from splashing. The car ran fine.

It's mostly when parked that the water collects in that elbow just behind the filter. When you start the engine (and especially if you rev it immediately after starting) water can get sucked up in a big glob. The engine can't handle large quantities of unvaporized water. If it's enough but not too much, this is when you feel the symptoms that you did. The engine is just BARELY managing to cope. If it's too much, the engine will seize (aka: hydrolock).

 

good info.

xviper, is that umbrella restrictive in any way? IE, does it negate any of the affects of the CAI?

 

I don't think so. It doesn't actually touch the filter surface. There's enough room in between for air to pass by. Guys who have made their own out of milk jugs can allow for even more space.

 

I also have the AEM V2 cai. I have had a piece of black electrical tape over the drain hole under my hood for over a year with excellent results. This includes my car being parked outside during three hurricanes that dropped between 6 and 14 inches of rain each time. I have had no water in my intake tube at all (I have checked). The filter has been damp after driving in the rain, but like xviper said, this is not harmful. The filter stays totally dry while being parked outside even during the heaviest downpours.

 

I do have that hole plugged up with a homemade silicone blob, along with one a little further down with a classic small sink stopper. The umbrella idea is a good one which I'll probably work on when I reassemble the intake.

I just wonder if it sucks in a little vapor or mist over many days or weeks, why wouldn't it condense into a pool of water eventually? It just feels like it's a combination of things that all contributed a little bit of water to the problem.

 

it's very unlikely that mist or vapor sucked into the intake would ever consense enough to form a pool of water in the intake. it would just continue it's way on up the intake since it's such a fine mist, and would evaporate before it reached the engine or by the time it got to the combustion chamber.

 

It may all depend upon how well your filter is oiled. The K&N type of filter uses a cotton gauze material. If it is oiled well, water (from splashing) will not be retained in the filter media. When it falls out, some will work its way into the pipe, some will fall harmlessly to the outside. As long as there is no water falling from above, the filter should not get any wetter.
If you have been driving around with a high splash factor, it might be a good idea to rev it up a bit to draw more of the moisture from the filter just before turning the engine off. This way, there is less that will drip out as the car sits.
Do the umbrella when you put the system back on as I think water is still getting to it from above from somewhere other than the one you've plugged already.

 

i dont have the v2 CAI but similar construction using the Apexi intake. Was raining heavily on my way to work ( 50kms drive) today and some part of the road contain lots of large puddles.

Was worrying like sick for hydrolocking as my intake is fully exposed by the c-west kit. Luckily my car is running fine. BTW, i have the piping custom made, the intake doesnt point upwards, and had an "umbrella" attached to it.

 

I had that same problem... 3 times. One of the three times I actually smelled coolant after it cut out! I figured it had blown the head gasket or something... but I did compression and leakdown tests and all is well. After being paranoid to death about it I finally purchased a Comptech intake. I miss the power and the noise of the AEM... but hydrolocking my motor is just not worth it.

BTW... I have an AEM V2 for sale if anybody wants one.