Water in plug hole

[Egill]

First time poster, long time reader on this great site

I have a weird problem

The car is a 1993 525 with the M50tu/b25 motor

My car started acting up (erratic idle and then the occasional surging under load) and I had my dealer plug it into the computer. Turned out my o2 sensor was throwing some signals so I bought a new one and changed it.

The idle fixed but still the occasional surge. So today when it started surging I pulled to the side of the road and started pulling connectors to the coils (already had my top cover off since I was troubleshooting the Idle). I found that cylinder nr6 wasn't doing anything so I pulled the coil out and found that there was a small amount of water in there :? Dried it off and everything was fine.

So my question becomes: Is there any way for water to get into the spark plug hole other than from the top, say if I drive into a big puddle of water and some splashes into it :? Been quite wet here these last days.

[whiskychaser]

First time poster, long time reader on this great site

I have a weird problem

The car is a 1993 525 with the M50tu/b25 motor

My car started acting up (erratic idle and then the occasional surging under load) and I had my dealer plug it into the computer. Turned out my o2 sensor was throwing some signals so I bought a new one and changed it.

The idle fixed but still the occasional surge. So today when it started surging I pulled to the side of the road and started pulling connectors to the coils (already had my top cover off since I was troubleshooting the Idle). I found that cylinder nr6 wasn't doing anything so I pulled the coil out and found that there was a small amount of water in there :? Dried it off and everything was fine.

So my question becomes: Is there any way for water to get into the spark plug hole other than from the top, say if I drive into a big puddle of water and some splashes into it :? Been quite wet here these last days.

The coils bolt down so it would have to be a big puddle Maybe you park on a hill and the rain creeps underneath by surface attaction?

[Ferret]

The coils bolt down so it would have to be a big puddle Maybe you park on a hill and the rain creeps underneath by surface attaction?

Is the rubber seal at the back of the engine bay in good repair, and the cover over the sparks relatively in good nick?

[whiskychaser]

Is the rubber seal at the back of the engine bay in good repair, and the cover over the sparks relatively in good nick?

Dont think mine has a seal at the back of the engine, Andy

[Dave M]

Is the rubber seal at the back of the engine bay in good repair, and the cover over the sparks relatively in good nick?

This is the key. As the OP was driving without it (presumably in rain/wet roads) I would expect a plug well (or two) to have water. Something about an M50 without the plastic engine cover just screams "wet my plug".

Dave

[Egill]

This is the key. As the OP was driving without it (presumably in rain/wet roads) I would expect a plug well (or two) to have water. Something about an M50 without the plastic engine cover just screams "wet my plug".

Dave

Thank you all for your inputs.

These last few days (rainy days) the plastic cover has been off so I'm hoping that's just it.

At first when I saw the water I thought "oh no coolant" but it was so clear it couldn't be. And how the hell would coolant get there anyway.

Again, thank you all