Checking It Cold

2661 Views 14 Replies 5 Participants Last post by toobroketoretire, Oct 4, 2012

toobroketoretire

Discussion Starter · Oct 1, 2012 (Edited)

I have always checked my transmission's oil level hot and with the engine running just like the dipstick told me to. But I just discovered I can check it cold and with the engine shut off after it sits overnight and it's every bit as accurate. I just marked my dipstick at the "cold" level which is about 4-5 inches above the hot and running level.

When you shut your engine off your torque converter immediately begins to drain until the oil level reaches the bottom of the drive snout. And as it drains the level in the pan rises until the oil rises up into the dipstick tube.

To me it makes more sense to check it cold as that's when I check my other fluid levels.

I think the reason why they recommend checking it hot and with the engine running is most people only raise their hoods when they gas up and by that time the oil has warmed considerably and a good portion of the oil is still in the torque converter.

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Pappytinker

· #2 · Oct 1, 2012

Sorry, that seems to conflict with what this says;

http://www.ehow.com/how_6621905_check-fluid-hot-cold-engine.html

If the fluid drained from the torque converter, wouldn't there be some lag time between when you start the engine and when you could begin to move the vehicle.

[email protected]

· #3 · Oct 1, 2012

I ve always checked them warm, running in Park, so that fluid is expanded and flowing .. don t recall ever seeing any "cold full" marks as that link suggested

Slicktop

· #4 · Oct 2, 2012 (Edited)

That link is correct for some cars. My 4Runner has the hot and cold marks on the dipstick, and the cold marks are below the hot marks just like stated in the article. Different cars and makes have different procedures. It is best to stick with what the manufacture says to do to check the fluid level for a specific car, period.........

toobroketoretire

Discussion Starter · #5 · Oct 2, 2012

I have been checking it every morning for several mornings and I have found the level is always in the same exact spot. And yes, there is a "lag time" as a great deal of the oil in the torque converter drains out overnight after shutting the engine off. If you don't believe me try starting it dead cold then immediately pop it into gear. It often takes 2-3 seconds before it begins to move.

I'll check it again this morning and see if it has changed since yesterday..............

toobroketoretire

Discussion Starter · #6 · Oct 2, 2012

Slicktop said:
That link is correct for some cars. My 4Runner has the hot and cold marks on the dipstick, and the cold marks are below the hot marks just like stated in the article. Different cars and makes have different procedures. It is best to stick with what the manufacture says to do to check the fluid level for a specific car, period.........

I had to re-read your post several times before I realized you were talking about cold and running.

I have been experimenting with checking mine cold with the engine off after sitting overnight and it seems to be just as accurate as the fluid has been returning to the same spot.

When you shut your engine off the oil in the torque converter begins slowly draining thru the pump's front sleeve bearing and back into the pan and by morning close to half has drained. Which raises the level clear up into the dipstick tube about 4" above the full mark.

Slicktop

· #7 · Oct 2, 2012

toobroketoretire said:
I had to re-read your post several times before I realized you were talking about cold and running.

I have been experimenting with checking mine cold with the engine off after sitting overnight and it seems to be just as accurate as the fluid has been returning to the same spot.

When you shut your engine off the oil in the torque converter begins slowly draining thru the pump's front sleeve bearing and back into the pan and by morning close to half has drained. Which raises the level clear up into the dipstick tube about 4" above the full mark.

That is only on your car. Just for the hell of it last night I checked the level in my 85 l98 cold before starting it and then hot and running after going for a drive.

Cold and static the level was about an inch below the full mark and when hot and running the level came up to the full mark. My dipstick on the vette says to check it hot and running.

bpassmore

· #8 · Oct 4, 2012

I have a mark I put on the dipstick on all my cars that I use when the engine/trans are cold. It has seemed to be a stable indication of the fluid level.
The requirement of a warm check is probably the difference of the ambient temps in the different locations around the world, the warm check would produce a stable level. A 1/2 pint one way or the other doesn't seem to affect the operation.
BTW mine cold is 2 1/2" above the full hot level, '82 700-4R with Dex VI. My '04 Blazer is about the same.

toobroketoretire

Discussion Starter · #9 · Oct 4, 2012 (Edited)

bpassmore said:
I have a mark I put on the dipstick on all my cars that I use when the engine/trans are cold. It has seemed to be a stable indication of the fluid level.
The requirement of a warm check is probably the difference of the ambient temps in the different locations around the world, the warm check would produce a stable level. A 1/2 pint one way or the other doesn't seem to affect the operation.
BTW mine cold is 2 1/2" above the full hot level, '82 700-4R with Dex VI. My '04 Blazer is about the same.

Hey bpassmore, would you do me a BIG favor? With your engine running would you stick a small rubber hose (or something similar) down your dip stick tube until it bottoms out then pull it out and measure how much of it got oil on it? Ever since I put the TH700R4 in my '71 (that came out of a 1991 van with a 5-foot long dipstick and tube) I have been trying to determine exactly how much oil should be in it. I couldn't find a stock dipstick tube and dipstick so I cut the 5-foot tube and 5-foot dipstick down to a length that appeared right then marked the dipstick at the 10 and 11 quart levels.

The problem I have had is the conflicting information I got out of my '82's shop manual as it called for "about 20 pints" for refill and 23 pints after a complete overhaul. Well, I tried the 23 pints and that caused severe foaming and very abnormal shifting. So I drained my pan and convertor (they both have drain plugs) and started over by putting 10 quarts in it. With my engine running sticking a 1/4" hose down the tube reveals an oil level of exactly 1-1/2" and that seems to be working perfectly. When my oil is cold it's about 5/8" below the 10 quart mark and right on the the 10 quart mark when it's warm.

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toobroketoretire

Discussion Starter · #10 · Oct 4, 2012

I have been checking my oil level cold and with the engine not running for the past 5 mornings and it's always at the same exact spot. So that tells me it would also be an accurate way of checking the oil level. It may not be as accurate as checking it hot and with the engine running but I find it's a nice way as before I take a trip I check my other fluid levels cold.

Most folks don't know that after they shut their engine off the oil in their torque converter slowly drains thru the small gap in the front pump bearing until almost half of it is back in the oil pan. That's why the car won't move if they start their engine then immediately pop it in REVERSE or DRIVE as their converter is only partially filled.

Slicktop

· #11 · Oct 4, 2012 (Edited)

You are confusing me or maybe you are confused:

"I just marked my dipstick at the "cold" level which is about 4-5 inches above the hot and running level."

"When my oil is cold it's about 5/8" below the 10 quart mark and right on the the 10 quart mark when it's warm. "

bpassmore

· #12 · Oct 4, 2012 (Edited)

Sorry it took so long:thumbsup3:. I used 14 ga house wiring, it ran pretty straight. The level cold was 5 1/2" off the bottom of the pan. The top of the filler tube was 26 3/4" off bottom of the pan.
The pan is stock Corvette, not an after market. The level on the stock stick was 5", so the dip- stick sits about 1/2" off the bottom.
I'll get the warm/hot figures this afternoon.

bpassmore

· #13 · Oct 4, 2012

Hot check = 2 5/8" to full. Trans temp around 240*. Gauge wire touching bottom of the pan. Hope this helps. OAT here is 92* (Good ole Gulf Coast)

[email protected]

· #14 · Oct 4, 2012

your trans normally runs 240*? that a bit high, you should add a cooler or at least change fluid more often

toobroketoretire

Discussion Starter · #15 · Oct 4, 2012

Slicktop said:
You are confusing me or maybe you are confused:

"I just marked my dipstick at the "cold" level which is about 4-5 inches above the hot and running level."

"When my oil is cold it's about 5/8" below the 10 quart mark and right on the the 10 quart mark when it's warm. "

Okay, I'll further explain it. When I go out in the morning I pull the dipstick (engine off) and it reads about 4-5" above the full mark. Then after I start it it'll show about 5/8" below the full mark. Then after driving it for about 30 minutes it'll show full. So I'm talking about two different "cold" levels; one being what it shows with the engine off and one right after the engine has been started (but the transmission is still cold). From what I've seen over the past 5 mornings the "engine off cold level" is always in the exact same place.

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