This is the second time this has happened (luckily it hasn't rained to much here lately in Dallas) this year. I left my truck outside after a good rain and now my truck is running rough and the Check Engine Light is on.

Last time my mechanic pulled the plugs there was water in the last cylinder on the drivers side (sorry I do not know what the cylinder number is). I wouldn't be surprised if that's the case again now. It's late and I didn't get a chance to really look at it today because of work but I will tomorrow.

Any ideas where the water can be leaking in? I'm thinking it's from the cowl but could use some opinions on what to look at tomorrow. Any help would be appreciated.

 

I would also guess that its leaking from the cowl/firewall, that number 8 plug is pretty much right under there.

One thing you can try is using a hose to spray a bunch of water over the front of the truck and see if you can locate the leak (do this when the truck is dry obviously).