I have a Ford F150 1997 model and it’s been running like it’s missing and when I had the oil changed recently they found water on the oil cap and when I looked there is water all down in the pipe the cap goes on. When I check the dipstick there is no water. Check engine light just came on also. I have not driven my truck through any high water and flooded it so this doesn’t make any sense to me. Where could the water be coming from? I do not want to lose my truck engine again it’s already been replaced in 2002 and has been treated like a baby since so I’m at a loss.
first, get the check engine light read at Advance Auto or some Autozones, for free and post back.
As to water in the oil filler neck, can you define how much? I would normally ascribe small amounts to condensation. Does this truck get driven daily, and does it get to go out for some long drives? If so, the water should get eliminated on these trips.
It’s possible the missing has nothing to do with the moisture in the oil or engine.
What engine do you have in this truck? The 4.6?
I have a 6 cylinder 4.2 I believe and it’s got a jasper engine in it as we had to replace the original in 2002 due to the previous owner’s negligance. The only place we can find the water/moisture is in the neck of fill hole and on the cap. When running it starts as it always has but when you put it in gear and try to take off and press the accelerator it shudders and gives me problems until I let up and then just let it ease up to the speed I need.
For a first step I would advise dropping by a local AutoZone, Advance, Checkers, auto parts store and have them check for any codes. It only takes a few minutes and they will do this for you free. Post any results for discussion.
The water in the neck of the fill hole may not mean anything. This could be condensation due to driving habits. If you do a lot of short hop, stop and go driving this can occur normally; especially in cool, damp climates.
(Think of a sweating window; same thing with an engine)
The rough running could be an ignition miss, etc. but getting the codes should be step no. 1.
ok4450…THANK YOU SO MUCH…my hubby went and got the computer to run the diagnostic ourselves and not pay the garage and what do you know it told us that I had water in the fuel lines and it had multiple missing issues. A fuel treatment to get the water out of the gas and a complete change out of the spark plugs we did ourselves fixed it all! The garage wanted $100 to run the same test and then $269 to change out spark plugs? I told them they were nuts and nevermind. Now it runs just as wonderfully as it always has and I had no more problems. Thank you for your insight it is much appreciated and saved us a LOT of money that bought me a much needed stove instead.
The code scan will tell you that multiple missfires have occured,it won’t tell you that water in the fuel caused them.
This “water in the fuel” diagnostic feature would be very nice if it did exist as many people including mechanics resort to the “water in the fuel” explaniation.
If you care to what, was the “water in the fuel” code.
Oldschool, that one is pretty comical. I’ve looked in my books and can’t find a “water in the fuel” DTC either. 
OP, you’re not out of the woods yet. You replaced the plugs and it runs fine. The only question would be if stays this way. A weakened coil, engine problem, fuel injection system problem, etc, etc, etc, could have been what was behind killing the spark plugs.
And tha garage is not ripping you off. The garage MUST charge for things like checking codes and they MUST charge a flat rate hourly charge against book time or else they cease to exist. Two hundred sixty nine dollars sounds like a lot of money for plugs (and it is) but consider this. If you’re on the east or west coasts where labor rates run a 100 and way more per flat rate hour then a couple of hours labor + a set of marked up platinum plugs can very easily make the tab hit 200-300 dollars.
The parts store has a different business model and the guys there are paid (not much generally) by the hour; no matter if they’re pulling codes for you or twiddling their thumbs. If a shop scans a car for you free then this means the shop is losing time (money) plus the mechanic scanning the car is doing it for free.
The latter can lead to a bit of tension if the kids need new shoes.