Was on a small road trip a couple weeks ago. We were at a gas station filling up and I decided to check the oil. My wife came up to me and pretty much implied that I was stupid & said "You don't check the oil when the engine is still hot". She said the same comment a few days ago. Never heard of this before. Why would you need to wait till the engine's cooler? I understand to wait a few so the oil can make it down to the pan. Please tell me she's not correct.

Brandon

 

never heard of that before, I usually wait about 10 or 15 minutes after engine is off to allow drain time to the pan but thats it. I don't see what difference it would make if the engine is hot or not.

may be one of those "OLD WIVES TALES", lol

 

Women :roll eyes:

I'm joking about the woman bashing thing there.

Let the oil settle a little bit, check it, hot, cold, it doesn't matter with engine oil.

 

My mother said the same thing. I tried explaining people say "Don't check it with the engine hot" because the oil needs some time to make its way down to the pan. But she insists that isn't the reason why

 

its probably better to check it when its hot. it isnt as thick, and will drain faster.

 

Yea......

I was thinking "If it takes more than 2-3 minutes for your oil to drain back in the pan, you've got other problems to worry about."

I suppose it's just like any other lube. It'll increase in area (take up more space) just like tranny fluid.

If anything, you're safer to check it while it's warm just to make sure you don't OVER fill it.

 

Most people have some knowledge about cars that they've picked up over the years, but it's not likely based on reason or real knowledge of how things work..its just something they've heard and now believe. The only reason you wait is so that the oil drains back into the pan, it doesn't need to cool off. After all, the oil is hot when it's running, and that's when its volume is important.

It's pretty common that people think things like this, you just have to explain to them why it doesn't matter or doesn't make sense. Some people are too bullheaded to believe you or accept that something their friend/brother/dad/bill cosby told them is wrong, though. I had a friend that insisted all cats would gorge themselves with food until they died, but her cat was smart because it didn't. She wouldn't accept that the idea was patently absurd.

 

I'm with AJ. (Those guys from Clifton are pretty sharp.)

If you have more than an insignificant and almost immeasureably small (at least as measurable by a dipstick) amount of oil that hasn't drained back to the pan in the amount of time it takes you to walk out front and open the hood, you're going to have some serious oil starvation problems at any kind of RPM, like road speed.

Consider that if the theory is that it takes 2-3 minutes for the oil to drain back, the oil pump will put all the contents of the sump into the rocker area in about the first half block of driving, and the rest of the time you're lubricating with air. Maybe that's how that DuraMax **** is supposed to work...

Have your roommate study this diagram and see why no significant amount of oil will remain in the heads and lifter valley for more than a few seconds:

 

at least she didn't say that you shouldn't change your oil as long as the car runs good and should just add some more when it starts burning it up... (I heard that before ! lol)

 

She got this from her uncle who is now a police chief but is also ASE certified and many years of automotive mechanics. My wife needs to hear things, like this, from only one person and then she believes/practices it from then on, despite if the source is credible or not. Me...I like to hear from a few folks, then practice/believe.

Brandon

 

Gee..... that sounds familiar. I'll bet our wives are the only ones that act like that, huh?

 

Until a few years ago, AMSOIL would say to check the oil level after the engine had been off for at least 6 hours. The reason for that is that their oil would "cling" more than other types, and therefore would take longer for all of it to get back into the pan (this is just a thin layer clinging to metal surfaces, not a bulk return issue - no problem while the engine is running). If you checked it right after shutting off the engine, they said to read the stick one quart lower than indicated (to avoid over-filling).

They haven't been emphasizing that with their recent formulations. Drain-back is apparently quicker with them.

GM says to check the oil on a level surface after the engine has been off for one minute.

 

Ther you go. A respectable member, representing a reputable lubricant manufacturer, and relay information for THE reputable vehicle manufacturer. What else could you want?

Now go back to porting those Mk-IV heads, will ya? About finished yet?

 

Simple, things expland when heated (usually).

Look at the tranny dipstick. It will have a hot and cold marking. And the cold marking is about a quart lower than the hot marking.

 

The heads are done. I spent a significant portion of Friday, Saturday, and Sunday working on port-matching the headers. This is called, "Getting a square peg into a round hole", where the square's side dimension is the same as the round's diameter.

Question: Know what happens when you die grind on a header flange opening that has the tube located too low in the flange?

Next question: Know what happens when you try to add material to the tube?

Back to the original question: I haven't seen an engine dip stick with "hot" and "cold" markings.

Another oil level observation: Manufacturers typically design the system to operate 1 quart below the add mark - because they know most people just don't check the oil often enough.

 

Oh, no...

OH, NO!

I saw that one coming as soon as I read the first line. Do you know a good TIG welder? If not, is there a boat propeller repair shop in your area? They're usually very good at fabricating in non-ferrous metals and very thin sections. Maybe you could have a shell of 304SS rolled up and fit to fill the area between the flanges and head pipes. That's gotta blow big time. And everything seemed to be going quite well. Fraggin' gremlins...

 

A little off the subject.....been running my 83 Z without a dipstick for a while now. How easy/difficult is the replacement process? We're talking about a dipstick/tube replacement.

Brandon

 

IIRC we had a Cat log skidder that had one side of the dipstick marked for checking the oil with the engine off, and the other side marked lower for checking the oil with the engine running.
Not really relevant to the topic at hand, but kind of interesting.

 

Pretty easy to replace a dipstick. Vader will tell you that it's as simple as finding the proper hole, and cramming it in there

 

I need to clear something up here - I don't "represent" AMSOIL. If you asked them if I do, they will say only if I am quoting material published by them. Since I wasn't directly quoting material published by them in this instance, I was not "representing" them.

I'll certainly agree with the "reputable lubricant manufacturer", though.