V10 6.8 Rusty oil Dip Stick

[Grumpy Grampa]

I replaced the oil dip stick on my v10 6.8 Triton engine, about a year ago because close to the top it was rusty. Today it’s doing the same thing. The new dip stick was purchased from ford.

Thoughts

[lwmcguire]

Very common due to moisture condensation

[abjbrtd]

Ours was like that when we bought it, wasn't new with few miles on it.

Hasn't been a problem since, but we do drive it and run it often

[OldWEB]

Originally Posted by lwmcguire

Very common due to moisture condensation

Which is very dangerous to an engine. If you (OP) are running it a lot for short periods of time, the moisture created does not have a chance to dissipate or if your PCV valve or line is blocked it cannot evacuate the moisture. If the dipstick is rusty, what else could be??? In really bad cases, the moisture shows up in the oil as a whitish mess.

[Chateau_Nomad]

The oil dipstick is VERY long (as you know), and it takes a while for the engine oil to warm (by convection) the entire length of the dipstick. Also, the top of the dipstick where it seats in the tube doesn't have a positive seal - which allows air to enter.

As the engine (and oil) warm up, the air around and inside the top of the dipstick tube is gradually warmed... faster than the dipstick at it's top near the seat. Moisture from the warming air in the top of the tube will condense on the cooler top portion of the dipstick (picture a cold beer on a hot humid day). The iron particles in the steel dipstick rust from the moisture. As the entire dipstick warms, the moisture will evaporate - exposing the rust.

If that process worries you, pull the dipstick out frequently and coat the top portion with oil, which will prevent oxygen/moisture from contacting it. Otherwise, sleep well. There is no reason to panic - it won't damage your engine unless a significant amount of rust/debris falls down the dipstick tube. But hopefully you are checking your oil/pulling the dipstick frequently enough to prevent that.

[Sappy2]

If it is just on the top few inches, this is not harmful. Do not worry about it and make sure that it is seated well. If the rusty crap is near the bottom in the oil on stick area, then I would suggest that more frequent oil changes are needed. Oil gets corrosive from combustion gases. And, short engine runs can cause moisture not the be dissipated if the engine is not "driven". But what your describing is not a big deal.

[Grumpy Grampa]

Thanks for all the advice.