The dreaded oil-filler cap condensation!
 

Well, while having my oil changed, some condensation was discovered on the oil filler cap. I've heard this is often a sign of a head gasket failure. However, I have not discovered any water/coolant on the dipstick. It also seems to be running at normal temp., and it's not using any coolant(that I can see, anyways). I've heard that driving short distances can cause condensation to build-up, and I do have a fairly short commute to work(10 mils one-way), but the engine always reaches operating temperature.

I have heard of head gasket problems on the 5.4L. I've also heard that a clogged PCV valve can cause condensation. Thankfully, I did buy an extended warranty with the truck, so the repair won't put me in the poorhouse.

Now, I'm wondering what to do. Should I take it to the shop immediately, or keep driving it while keeping an eye on the condensation?

My truck is a '99 with the 5.4L, and 74,500 miles.

10 miles on a 5.4 is a short trip, especially during the winter. Take it out on the highway for a while then check it.

Just because the temperature gauge says the water is warm, it doesn't mean that the engine is warm.

I have heard that a certain amount of condensation on the cap is quite normal (especially with relatively short drives). If you found a milky substance on the dip stick or in the oil itself, that would be a different story.

Thanks for the responses. I'll keep checking the dipstick, and I'll check it after the next highway run I have. I might even look in to having an oil sample analyzed.

It,s normal in colder weather for such short trips!

I get the milky crud under the oil cap in the winter with my short trips to work, but it's gone in the summer months. I just change the oil more frequently in the winter.

i have a 97 ford f-150, 4.2 V6 and i have the same problem. in the winter i have the milky substance on the cap but not on the stick. then in the summertime its gone.

i checked it after driving 3 hours on the thruway and its clean. I just checked it after a week of town driving and its back....just a little though, i just wipe it clean

Use synthetic problem gone!!!

not true.....i switched to AMSOIL and i still get it a little

Well, I took a pretty good drive a couple of days ago, checked the oil cap, still had crud on it. Checked the dipstick, nothing but clean oil. As I remember, I don't think it ever had that stuff on the dipstick. I'm not all that worried about it now, based on what I'm hearing on here. I'll just keep an eye on it!

The crud is condensation in the crankcase. The pcv valve is supposed to remove it, but if you only take short trips, it hasnt got a chance to do its job. Chrysler v8s have the same issue going on. They've issued a baffle to put in to the oil filler tube to keep the crud from reaching the cap. Just make sure the pcv valve is functioning and the tube isnt stopped up.

Actually It verry common, I used to work in a shop and change oil and 90% of them do this in the winter months, short trips dont help it doesnt allow the oil to heat up enough and get the condensation out, it will usually only form on the cap, DONT WORRY!!!, change your oil a couple of times in the winter if your concerned.

Funny that you mention that. My dad had a '94 Dodge Ram with a 318, and he had the same problem. The dipstick even rusted at one point! He kept having it looked at and tested, but there was never a leaky head gasket the whole 118,000 miles he drove it. Not bad for a Dodge, eh?

I had the same milky oil cap on my truck, but the dip stick looked normal. I have a very short drive to work, in a very damp climate. I wiped it off and went for a 3 hour drive on the highway, and it hasn't returned since. These forums rock! Thanks.