Car Mechanics: Water in engine problem

So, I’m washing my car and think “I ought to wash the engine.” I don’t waterlog it, but I give it what I think is a thorough cleaning. I didn’t cover anything (distributor, battery, etc.), but tried to avoid what I thought were sensitive areas.

Fast forward two weeks, my car is still sputtering, mainly when idling or just starting from a stop. Should I try a gas additive to remove water from the engine? Should I just drive it for a while longer and just “let it dry out?” My car is a '94 Mazda so I’m not willing to spend money on it that I don’t have to.

By the way, the fact that I’m an idiot when it comes to the mechanics of cars goes without saying.


Sounds like water in the distributor, which means you have to pop it off and spray some wd-40 type product. It’s unlikey you got it in the engine, but it is POSSIBLE.

Most sensors and internal engine components are pretty safe from moisture, and you said you were trying to avoid sensitive areas.

But boy or boy did you make a mistake by not covering the distributor. Might as well replace it when you pop it off.

Thanks for the answer. I think that I can “pop off” the distributor, but I am an idiot.

Just for clarification, do I need to pop off the distributor cap (I think that’s the correct term) or do I need to remove more? I can handle the spraying the WD-40 part.

Also, pull of each of the spark plug wires (in turn–don’t pull them off all at once!) and dry inside. Water can get trapped in there and ground out the spark partially.

So you are left with two scenarios
First when you washed the engine some water got into where water should not be and caused the stumble / misfire that you are experiencing. The likelihood of this is high.
On the other hand the stumble / misfire could just be a coincidence. While I would not rate this as a real high likelihood, it could happen.
Most likely when you washed the engine you forced some water past a seal on one of the fuel injection components and it now has water trapped either in the connector or inside the component.
If you are handy, and feeling lucky you could try removing all the electrical connectors (One at freaking time, so you don’t mix anything up) you can find under the hood, and check for corrosion or the presence of water. If you find any water use a spray product called electrical contact cleaner to get rid of the water. If you find any corrosion clean it carefully with a small brush or emery board (Do I need to mention do all of this with the key off?)
If the water is trapped inside a component you probably won’t be able to remove it.
BTW is the check engine light on?

Rick: No, the check engine light does not come on.

I do think that I’m handy enough to try the drying the electrical components thing.

Rick appears to be brain dead this afternoon as he completly spaced on water inside the distributor cap.
On suggestion do not remove more than one wire at a time from the cap, and do not remove by pulling on the wire. You could break the inside of the wire and cause another problem. Grasp the boot and twist.
On a Mazda you will probably find the distributor cap secured by screws (Phillips?)

This wouldn’t be a four-cylinder, would it? If memory serves me, these have the spark plugs come out straight up. The plug wire boots are long and have a “hat”.

What happened when you washed it is you got water in the hole where the spark plug resides and now the spark is shorting out to the cylinder head.

To fix it, remove the plug wires at the spark plug end (one at a time) and dry the water up. It can be tricky to get the water out, but sticking a paper towel in the hole should get it.


I wouldn’t always put wd40 in there, it’s flammable. They do make products you can use however.

Could be a whole host of things. Open the oil cap & see if there is any water on the inside of the cap.

Most likely if you got water where it don’t go,surely the engine got hot enough to evaporate it by now. With the engine off pull one wire from the distributer cap and start the car to see if it was that cylinder that is the problem, do this on each cylinder until you find the one that is the problem. didn’t find it? take the distributer cap off and check inside for cracks and signs of arcing, also check the carbon button on the inner top, they wear out.
Ano;ther possibility is you got water in the gas tank, put some gas dryer in your tank.