Very silly actually.
Not a fight, not at all. Just two people brought up doing things differently. I was always taught "check the oil when the engine's cold and check the transmission fluid when the engine is hot". My neighbor insists that transmission fluid has to be checked when the engine is cold. We bet a case of beer on it.

We have both agreed to abide by the decision on this site.

 

Transmission fluid expands as it is heated. Since the normal operating environment of the transmission is in a heated operating environment, fluid level is best checked w/ engine at normal operating temperature. There exists more variation of reading transmission fluid level when the transmission is cold. Check transmission fluid level w/ engine at normal (hot) operating temperature. I check transmission fluid with engine at normal (hot) operating temperature w/ the engine running.

You want to read engine oil level with the greatest amount of engine oil located in the oil pan. I check engine oil (normally) when engine is cold & all engine oil has settle into the oil pan.

 

Exactly what Vintage Chief said. You win the case of beer.

 

^^^Yup, X2^^^ Hopefully you get to pick the brand and you and the neighbor enjoy it together.

 

You're both wrong. Every manufacturer has a different procedure these days. There is no blanket method for either.I recently worked on an old AC, proper procedure for checking the oil was while it was running..

 

Thanks guys. I'm easy going on the beer though. I don't have expensive tastes. A case of MGD will do nicely. He can bring it over this afternoon while I'm grilling and I'll supply the steak, baked potato and football on the tube.

 

I've found over time, it actually doesn't matter, the oil expansion is really minimal for engine oil. For ATF, I've done it both hot and cold with the engine running in park and the level may fluctuate 1/8 inch on the dipstick.

 

Transmission hot while the engine is running, and don't forget to run it through all the positions.

I never worried about the engine oil temp. Back in the day you'd pull into your local service station and the pump jockey would check the oil. It wasn't cold by any means you just shut down. Of course he'd tell you it was low anyway just so he could sell you a quart of oil.

 

My 2012 Expedition doesn't even have a dipstick for the transmission. You have to have it on a lift and take a plug out above the pan to check it. I have always been engine cold and transmission hot. As eric mentioned, I don't think it will really matter.

 

^^^THIS^^^

I check the ATF in my 71 98 HOT with the engine idling. I think it's etched on the dipstick. I check the oil cold, but the aftermarket dipstick I have is a POS.

I actually had to look this up recently for my 25 Kia Carnival and a friend's 13 Nissan Rogue. It was only 3 quarts low on CVT fluid.

 

On our older vehicles, 40-50 years old, it was always trans fluid hot, engine oil cold. Ya figure that the engine oil has to drain down into the block to get an acccurate reading. The owners manual is the best for what ever vehicle that you own.

 

The trans in my 64 is to be checked with the engine off. Cold or warm doesn't matter.

 

Here's a thought. Rather than debating this, why don't we just READ the Chassis Service Manual?

 

I had an '04 Jetta that was the same way. I remember going to check the transmission fluid after I bought her (used) and was in the process of swapping out all of the fluids and filters so that I would have a baseline. No dipstick. I made a few calls and was told that it was a "sealed unit" and to not worry about the fluid or filter unless I wanted to spend $300 for a flush. I flushed it anyway.

 

Here's another thought, the op didn't mention a specific make or model. So without that information the debate has always been a headless horse.

 

If the interwebs are any indication, the only cars Olds ever made are 1970-72 A-bodies.

 

Yes, you are right as Joe points out here. But there is a range on the stick, cold is the bottom mark on the cross hatch, idling in Park on GM vehicles. Yeah, the ZF 8 speed in my Challenger has no dipstick. It has to be between 86 and 122 degrees max. It should trickle out the fill hole running in park on a level surface.