When I checked my oil a week ago, there were rusty spots on the dipstick, and it didn't slide in and out of the tube very well. I don't believe I have coolant in my oil (ie. headgasket problem), but I'm trying to figure out what might cause this.

I did an oil change about 9 weeks ago, and there was no problem. About a month ago, I used a car wash pressure washer under the hood to clean up some leaks, so I'm thinking maybe the water got through the dipstick o-ring seal (the o-ring probably needs to be replaced anyway). The pressure washer theory likely holds, since I used one again today, checked the dipstick later, and found water on it. I would have thought there'd be enough oil swishing around to coat the dipstick again, but apparently not. In an attempt to stop the rust, I sanded down the rusty parts of the dipstick and then coated them with oil.

Checking it today, it was worse than ever. I'm thinking now that the sanding removed the original surface treatment and worsened the situation. I intend to replace the dipstick, but in the meantime, I decided to paint the upper rusty parts (try not to laugh!), as I figured this would be better that allowing rust to drop into the oil pan.

Since the tube seems rusty also, I draped some thin cloth with a small knot in it over the dipstick, and slid it up and down the tube a few times to try and clean some of the rust off. I'm sure some particles dropped into the pan. Hopefully the filter will catch them, and I'll do another oil change soon.

If I can locate a dipstick tube, is it simple to replace? I believe I see it's held into the block by a bracket. If I disconnect the bracket, does the tube simply slip out of the hole in the block?