ATF foaming up

[researcher]

Originally Posted By: parshisa
Nope. Level is spot on and no foaming at all. I've checked the level several times both with the ATF up to the temp as well as after sitting overnight. i'm really confused as to what happened where and why


hey parshisa, i may be late in responding, but I had this happen on my scion (camry engine) when I filled the oil too quickly. I know it's just oil but I'm thinking the same thing can happen to the auto transmission as well. if I go really slow (painfully slow) then no bubbles, but if I dump quickly that happens.

By any chance did you just take a funnel, dump a quart in there, let it fill that way? If so, might've been how the bubble were created. Then later on you check and no bubbles, nothing wrong. just a thought for ya.

 

[parshisa]

No sir, adding the fluid was fairly time consuming process and there was no bubbles there for sure afterwards. I've driven the car and verified the level and it was right in between the dots. It was the following morning when this happened. Checked yesterday and this morning again - perfect level and no foaming. go figure. Thank you for the feedback and suggestion though

 

[parshisa]

So I checked the level this morning after car has been sitting for around 12hrs. It was a little over max dot. Started the car, shifted through the gears and shut it off. Pulled the dipstick and sure enough observed air bubbles in the fluid. But, if I drive the car and get the ATF to operating temperature - no signs of the air bubbles. So, it only does that on cold fluid and car is not driven. Does anyone have an explanation? Is it a bad fluid? Do I have an air leak? What's going on???

 

[Trav]

Depending on where the return line dumps fluid back into the unit that alone can cause a few bubbles. True aeration is like red foam not just a few air bubbles. I have seen it many times and it isn't an issue.

 

[parshisa]

Thank you for the feedback. It really is hard to say if it was doing it before since i’ve never looked at the fluid with the car just started and ran through the gears. I’ve pulled about 0.2qts just be sure that the amount i’ve added after draining matches the book number. Level appears to be slightly above min now. I’ll give it another try tomorrow morning. Again, fluid is not foamy, just some air bubble. Once the car is driven a few miles fluid looks completely normal.

 

[TheLawnRanger]

What brand ATF did you use?

 

[parshisa]

Honda ATF DW1

 

[TheLawnRanger]

Have you read this?
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/950107/Re:_Bubbles_on_Trans_Dipstick

 

[parshisa]

Yes, i have. There was another on ehere on bitog a couple of years ago. Still no definitive answer though

 

[TheLawnRanger]

I was about to change my ATF. I may wait and see how this turns out. It does seem like the number of posts saying not to worry about it are much higher than the ones who think it's a problem. If your fluid level stays normal and there doesn't seem to be a problem, I think your ok. If you've ever had a transmission flush, it could be from residue left over from the chemical used during the flush according to a post on the Eric the Car Guy site.

 

[parshisa]

The car is at 19K so no tranny flush been done. I pulled a few ounces and will run the test tomorrow morning. If the fluid will be still airated in within a few first minutes after cold start - then that’s how it is with this transmission. I don’t see me doing anything wrong chamging it. It’s hard to believe there’s anything wrong can be done in a first place

 

[parshisa]

Did the same cold start/fluid look test this morning - same thing, it is getting airated at the initial start up and quick run through the gears. Any Honda AT owners there, can you'll do the same test and see what your fluid looks like? I'd greatly appreciate that