foam on dipstick: what does it mean?

Status
Not open for further replies.
Joined
Apr 13, 2004
Messages
49
Location
north carolina
Oil was a little low on the dipstick. So I added a little bit of what was handy. Was running Rotella T 15W40 and added a half a quart of some cheapo Car and Driver 10W30 that I had for the lawnmower. Oil is back up to the full line but now there is a little foam showing up. What does the foam indicate?

Vehicle is a 98 Tacoma with the 2.7 4cyl and 140,000 miles.
 
I searched for foam and air bubbles and saw some discussions. The jist of it was that it wasn't good. I got that. But the what's causing it and why is it a problem I didn't get.

Anybody?
 
If you mean a white milky substance when checking the oil when the engine is cold that does occur in the winter when condensation occurs in the crankcase and it shows up on the bottom of the dipstick. If on the top when hot, got me. Too much oil can cause foaming but I have never seen it on a dipstick.
 
Are you referring to bubbles immediately after top-off or some real small foamy bublles at the top of the dipstick?

Maybe overfill?
 
nanney,

Too bad no one here has helped you out......the topic doesn't include GC oil ( I hope that doesn't upset anyone)
rolleyes.gif


Anyway, my man......foam on the dipstick is not good. I cannot think of any other reason for oil getting whipped up inside the crankcase than internals coming in contact with it. If the oil level is too high, the crankshaft will turn the oil into foam, and foan does not lubricate. You need to check your oil level and make sure you are taking a correct reading making sure the dipstick is going in all the way......it's a bit deceiving sometimes. Obviously, if it's overfilled, you need to drain some.
Also, although it might be very rare, I assume a bad quality oil without enough antifoaming agents could foam very easily. What kind of oil are you using?
It's probably very rare, but it's possible.

Hope this helps!
 
I haven't checked it cold. It's always been after the oil is hot. More like air bubbles than foamy though. I assume it had something to do with adding the 10w30.
 
The first thing I would do is change the oil to see if it was the oil you added to top it off. Get whatever is in there now out and see if new oil does the same thing. I would also try to underfill it slightly (maybe 1/2 way up the SAFE zone on the dipstick) and try it there for a while. Some dipsticks have been known to be a little off in the measurement.
 
Foaming on the dipstick and underneath the oil fill cap is normal around here in the winter time with any car that does short trips and does not get warmed up. Some cars are worse than others, those with long oil fill necks, such as trucks, will see alot of condensation foaming under the oil fill cap.

If you drive the car for 30 minutes or longer, and you still get the foaming, it could be a head gasket leaking antifreeze into the oil.
 
I'm changing the oil in the morning. I'm guessing the oil I added caused the foaming. We'll see. When I checked it before adding the oil, there were no bubbles.
 
quote:

Originally posted by nanney:
I'm changing the oil in the morning. I'm guessing the oil I added caused the foaming. We'll see. When I checked it before adding the oil, there were no bubbles.

You never said what oil brand you used!?!?!?
confused.gif
 
I had been using Rotella T 15W40 and there had been no air bubbles previously. After adding a little of the Car and Driver "mystery" 10W30 to top it off, I noticed the bubbles. The car and driver oil was some cheap .99 cents a quart oil I picked up at Target in the Spring when I changed the oil in my lawnmowers. I had a half a quart left so I figured what the heck, and added it in.

I checked it again yesterday afternoon after a 30 minute drive and found no bubbles??? Perhaps the two oils needed to blend together. Who knows. Changed out with Penzoil 10W30 this morning. Will continue to check for bubbles.
 
Status
Not open for further replies.
Back
Top