[robster]

I cannot find anywhere on here or in my owner's manual on how to correctly check the tranny fluid. After I changed it out a few times I checked it while it was warm and I seem to remember that it registered right at the top of the 'Warm' part of the dipstick. Well, when I checked it a while ago and it was totally cold it registered higher than the 'Warm' area, which I would assume to be the case (the fluid should settle more). It wouldn't be an issue except that on the dipstick there is a marking for "Cool" which is located at the bottom of the dipstick. That makes no sense to me. So if I went by the dipstick when the engine is cold I would be getting a reading that is way too high. Can anyone enlighten me on this please?

 

[romualds]

The following information is from 2005 Sienna Factory Repair Manual.
You can get it here: http://siennachat.com/forum/index.php/topic,805.0.html

CHECK THE FLUID LEVEL
HINT:
Drive the vehicle so that the engine and transaxle are at normal
operating temperature.
Fluid temperature: 70 - 80 °C (158 - 176 °F)

(a) Park the vehicle on a level surface and set the parking
brake.

(b) With the engine idling and the brake pedal depressed,
shift the shift lever into all positions from P to L position,
and return to P position.

(c) Take out the oil level gage and wipe it clean.

(d) Put it back fully into the pipe.

(e) Take it out and check that the fluid level is in the HOT position.

If there are leaks, it is necessary to repair or replace O-rings,
FIPGs, oil seals, plugs and/or other parts.

 

[robster]

Thanks very much.

 

[bcwang]

I have tons of trouble getting a good reading. Everytime I put the dipstick in and pull it out, there is fluid way over the correct level like it's picking it up from residue in the dipstick tube. Anyone know a good way to get a good reading? I've already tried putting it in different directions but the stick only seems to go down all the way in one particular orientation.

 

[jc]

How far over the fill line is the fluid? When I changed tranny fluid the first time on my 1st gen Sienna I think I put 5 litres in and it was about 1/2 and inch over the hot mark on the dipstick. It didn't cause any damage.

I'm sure you will be ok. If its bugging you that much then remove the drain pan bolt and let some drain out and top up if necessary.

Regards, Jason.

 

[samilcar]

Everytime I put the dipstick in and pull it out, there is fluid way over the correct level like it's picking it up from residue in the dipstick tube.

When engine oil dipsticks do this, a way to get a good reading is to pull the dip stick out and then wait 5 or 10 minutes before reinserting it. This gives a chance for any oil residue that's in the dipstick tube to drain back down so it doesn't smear all over the dipstick when you pull it back out.

 

[bcwang]

Let's just say if the dipstick was accurate, I think something would be broken because the fluid is like 6 inches over the hot mark. And it's more of a smear all over so there is no actual level you could say is the right reading.

You're supposed to read it while the engine is running right?

 

[jc]

If it's 6 inches above the fill line, how much fluid did you add to it? Did you let it all the old tranny fluid drain out? Maybe you should do the procedure again? When I did my first tranny fluid change it I added over 5 liters when it only needed 4 (even though I dropped the pan and replaced the strainer too).

You might want drain part of the fluid when it's cold (i.e. when the van has sat overnight), and then put the drain plug back in before it's totally empty. This wouldn't hurt, but may be a little messy.


Regards, Jason.

 

[bcwang]

I didn't do it, the transmission shop did it about a year ago. I'd hope a transmission shop knows not to overfill. Do you imagine the engine off checking would lead to a lower or higher level? I tried checking it with the engine off after 10 minutes and it was still this high smear. It seems the dipstick only goes in one way, every other angle I try to put it in results in it being blocked at some point of trying to put it in.

 

[robster]

I, too am assuming that the fluid checking instructions listed above are meant to be done while the engine is still running. At least that is how I read it. Per the instructions the fluid is meant to be read with engine at optimal operating temperature and running, but in Park (of course). I noticed that if I check it right after I turn the engine off it will read higher than when it is running. If someone is having trouble reading the dipstick then you might turn it around and look at the other side. Look for a point on it that is a somewhat horizontal line. That will be your level.

 

[romualds]

I, too am assuming that the fluid checking instructions listed above are meant to be done while the engine is still running.

That's correct. ATF level have to be checked while the engine is still running. In other case, the instructions told us to switch off the engine before checking.

 

[homer]

Confirm that all you have on the dipstick is tranny oil, nice and clear tranny oil, with absolutely no sign of coolant . A tranny cooler may let coolant going into the tranny raising the fluid level on the dipstick.

I'M just fishing here but hey you never know !!

 

[brian_bp]

Do you imagine the engine off checking would lead to a lower or higher level?

I noticed that if I check it right after I turn the engine off it will read higher than when it is running.

I believe this is how it works:
When the transmission is running, it pumps fluid up into parts which likely drain down to some extent when not running/pumping, so more fluid is down in the pan when the engine is off.

The same would presumably apply to an engine; I can only assume that transmissions are checked in the operating condition because fluid level is more critical to the transmission than to the engine.

 

[Old Crows]

Do you imagine the engine off checking would lead to a lower or higher level?

I noticed that if I check it right after I turn the engine off it will read higher than when it is running.

I believe this is how it works:
When the transmission is running, it pumps fluid up into parts which likely drain down to some extent when not running/pumping, so more fluid is down in the pan when the engine is off.

The same would presumably apply to an engine; I can only assume that transmissions are checked in the operating condition because fluid level is more critical to the transmission than to the engine.

Yes, I believe so. After sitting and cold, the fluid drains back to the pan. Once engine is running it pumps fluid to the top of tranny. The cold measurement is the minimum fluid quantity with the fluid cold engine running. The hot is the maximum with it at operating temperature engine running. Remember ...with the engine running the tranny pump is pulling ATF out of the pan and pumping it up to the top end so the level will be lower in the pan than engine off and it has been sitting. The AFT expands as it heats up.... hence the difference in measurements between cold and hot with the engine running.

 

[eluo]

After years of not knowing the correct level, I finally figured a way to get a clean reading off the Tranny dipstick without splatter / smear.

Procedure

1. Remove the tranny dipstick.
2. Clean up the dipstick and store in car.
3. Plug-up the dipstick tube with something. I used a Sharpie. It is not ideal size but it didn't fall off in my drive.
4. Drive around to reach temperature specified in post 2. I use an OBD2 scanner to read ATF temp.
5. Pull over on a flat, level, safe parking spot
6. With engine still running, insert the tranny dipstick and pull it right out to get a clean reading.

Note that this will work on the 1st try as the process of pulling out the dipstick will introduce ATF into the dipstick tube causing difficult reading on the 2nd attempt.

Additional tip - I have a transmission cooler and I didn't get to the operating temperature after 15 minutes of driving on the highway. I was able to raise the ATF temp by leaving the the van in drive while stopped with parking brake engaged and wheels chocked. The torque converter quickly raised the ATF temp. Once there, I shifted back to park and preformed the above measurement. ***Don't follow this tip without an OBD2 scanner to monitor the temperature***