Measuring oil - Cold vs Warm

[UnhandledException]

I just wanted to inform those of you who may not know this that there is a fairly significant difference in how dipstick measures oil between cold vs warm engine. I have been pretty OCD about this for several weeks now and I am 100% sure with data backing this claim that when engine is cold in the morning the dipstick shows about 2/3 full with respect to hashmarks whereas if you measure oil 15 minutes after engine reaches operating temperature (the manual), it shows right at hashmarks. That different is fairly significant. All measurements are taken in the same exact spot in my garage and I have done maybe 15-20 measurements at various oil levels.

You could continue measuring it while cold but you need to consider the above and not overfill. While I dont know what 1/3rd of the hashmark length constitutes, my unscientific method tells me the entire hashmark length from lowest point to top is 1 qt meaning 1/3 of the way is over 10oz.

Hope it helps folks.

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[rick81721]

I just wanted to inform those of you who may not know this that there is a fairly significant difference in how dipstick measures oil between cold vs warm engine. I have been pretty OCD about this for several weeks now and I am 100% sure with data backing this claim that when engine is cold in the morning the dipstick shows about 2/3 full with respect to hashmarks whereas if you measure oil 15 minutes after engine reaches operating temperature (the manual), it shows right at hashmarks. That different is fairly significant. All measurements are taken in the same exact spot in my garage and I have done maybe 15-20 measurements at various oil levels.

You could continue measuring it while cold but you need to consider the above and not overfill. While I dont know what 1/3rd of the hashmark length constitutes, my unscientific method tells me the entire hashmark length from lowest point to top is 1 qt meaning 1/3 of the way is over 10oz.

Hope it helps folks.

Do you mean the holes or the hashmarks? I thought the holes are what we should be looking at - the hashmarks are within the holes but not completely so.

 

[UnhandledException]

Hashmarks. The holes are there for some other reason but I strongly believe there is a correlation between cold vs warm oil levels and the distance between hashmark and top hole. I would say the top hole is the MAX oil reaches if you fill the car with oil while cold that gets you top of the hashmarks.

And when i say warm, I mean I drove the car around to get oil temp to 180F, then come home and park and wait exactly 15 minutes.

 

[rick81721]

Hashmarks. The holes are there for some other reason but I strongly believe there is a correlation between cold vs warm oil levels and the distance between hashmark and top hole. I would say the top hole is the MAX oil reaches if you fill the car with oil while cold that gets you top of the hashmarks.

And when i say warm, I mean I drove the car around to get oil temp to 180F, then come home and park and wait exactly 15 minutes.

GT350 supplement specifically states holes, not hash marks.

 

[SVTinAR]

Yep - warm liquids expand and cold contract. Get reminded of this every time I pour in a nearly full coffee cup of water into our Kuerig for a morning cup and it ends up running over the top.

 

[wildcatgoal]

Hash marks catch the oil. Holes are level meters.

 

[GT_Dave]

I just wanted to inform those of you who may not know this that there is a fairly significant difference in how dipstick measures oil between cold vs warm engine. I have been pretty OCD about this for several weeks now and I am 100% sure with data backing this claim that when engine is cold in the morning the dipstick shows about 2/3 full with respect to hashmarks whereas if you measure oil 15 minutes after engine reaches operating temperature (the manual), it shows right at hashmarks. That different is fairly significant. All measurements are taken in the same exact spot in my garage and I have done maybe 15-20 measurements at various oil levels.

You could continue measuring it while cold but you need to consider the above and not overfill. While I dont know what 1/3rd of the hashmark length constitutes, my unscientific method tells me the entire hashmark length from lowest point to top is 1 qt meaning 1/3 of the way is over 10oz.

Hope it helps folks.

You need to consider the volume increase in the oil pan as your engine warms up. The engine block will grow in length .025"-.030" between 70 degrees and 180 degrees, and the width will increase a corresponding ratio. The composite oil pan has a greater thermal expansion coefficient than the aluminum block, that's a significant change in volume and would be part of the equation in your study of the hot and cold oil level. Add to that the volume of oil will increase about 4% in the 70 degree to 180 degree increase, which would be about 2x the volume increase of the oil pan.
That increase in engine block length is what I consider as a priority as the car heats up in cold weather. The crankshaft length will increase only .012" - .013" in that 70 degrees to 180 degrees thermal window and the main bearings and thrust bearings need to take up that extra pressure during warmup.

 

[Rated R]

When oil is new in the pan sometimes it's so clean that you cant see it very well on the dipstick. The holes catch the oil. If there's oil hanging in the second hole then you've overfilled.

 

[DocWalt]

Yeah I dumped oil in without thinking about the car being cold when I checked it one morning, next time I checked it the engine was warm like normal and I was grossly overfilled. Oops...

 

[JAJ]

By George, he's right! From the supplement:

7. Put the dipstick back in and make sure it is fully seated.

• If the oil level is between the lower and upper holes, the oil level is acceptable. DO NOT ADD OIL.
• If the oil level is below the lower hole, add enough oil to raise the level within the lower and upper holes.​

​

I've always focused on the hatches because that's the way I was taught, and that's the way it's described in many (but apparently not in Mustang) owner's manuals. I have three Mustang manuals on file, and all of them refer to the upper hole as "MAX". The 2014 GT500 manual is different because it says "Full" is between the top of the hatches and the upper hole, but it's the only one. The rest refer to the upper and lower holes.

Now, the all-caps declaration not to add oil if it's between the holes is interesting. Most people on this forum probably try to keep the level at the upper hole. I top off to the upper hash mark if I'm going to the track. Otherwise I let it run down. However, because it sits all winter and goes to the track once or twice a month in the summer, it usually doesn't get very low.

One advantage of keeping it on the hatching is that it's never too low or too high, and you can read it cold or hot. Even if the reading changes with temperature, you won't overfill or let it get too low.

 

[UnhandledException]

By George, he's right! From the supplement:

7. Put the dipstick back in and make sure it is fully seated.

• If the oil level is between the lower and upper holes, the oil level is acceptable. DO NOT ADD OIL.
• If the oil level is below the lower hole, add enough oil to raise the level within the lower and upper holes.​

​

I've always focused on the hatches because that's the way I was taught, and that's the way it's described in many (but apparently not in Mustang) owner's manuals. I have three Mustang manuals on file, and all of them refer to the upper hole as "MAX". The 2014 GT500 manual is different because it says "Full" is between the top of the hatches and the upper hole, but it's the only one. The rest refer to the upper and lower holes.

Now, the all-caps declaration not to add oil if it's between the holes is interesting. Most people on this forum probably try to keep the level at the upper hole. I top off to the upper hash mark if I'm going to the track. Otherwise I let it run down. However, because it sits all winter and goes to the track once or twice a month in the summer, it usually doesn't get very low.

One advantage of keeping it on the hatching is that it's never too low or too high, and you can read it cold or hot. Even if the reading changes with temperature, you won't overfill or let it get too low.

Aha, got it. I mixed it up, thanks for the correction

 

[17RubyShelbyGT350]

Joined the OCD GT350 Oil Measuring Club

I never had a mustang before let alone a Shelby GT350 so after treating oil level measurement as a routine monthly check (or after a track event) in all the Corvettes I previously had (including 4 cam ZR-1, 3 Z06's (C5 & C6), and C6 ZR1) I now need to check oil much more often....:shrug:

Here is what I know:

1. Rightly or wrongly, the oil utilization of this FPC engine is a continuing major topic on these forums.
2. I bought my '17 convenience package car in the middle of October from a pos Ford store in Maryland after looking hard for this option in one of the colors I liked for many weeks. The car was originally ordered by a Tennessee dealership and was traded to the Maryland dealership (who likes to keep several of these cars in stock). Car had 37 miles on the odo when it got to Maryland.
3. After purchase and putting a very few gentle miles on the car to get it out of the pos Ford Store and ready for closed shipping to Fl, I saw the hot oil reading was mid-way between the two dipstick holes. I also realized there was (now) noticeable soot inside the four exhausts, mostly the inner two pipes. In retrospect, someone at probably the original dealership dogged the car hard for a few miles. Now, although that bothers me a bit now, I have talked to a number of folks included two well known aftermarket tuners who put their cars on the track and aggressively drove them immediately after they bought them.
4. Fast forward to today where I am just under 1000 miles. I drove the car pretty gently in the first 500 miles, a few brief runs up to 6k RPMs from 500 to 700 miles. From 700 to about 825 miles, several wots, several shifts at 8250 rpm. When I returned from that run, hot oil level was 1/8 inch above bottom hole. And Ford sez this is "ok."
5. Today, knocked out about 150 more miles, mostly highway, rarely ever going more that 4k rpm, mostly cruising in 5th at 80 mph. very limited decelerations using engine. Hot oil reading is still above bottom hole by maybe 1/16th of an inch and Ford sez this is "ok."

Do I have an oil usage problem? Maybe and maybe not.

So next steps:

1. Oil change at local Ford dealership (their service department has experience with these cars and seems to have a good reputation).
2. I will take an oil sample and send to Blackstone for analysis. I want to take a close look at the oil filter and its contents when it is changed out. I expect to see some crap in the oil and filter - but how much and what?
3. Starting with a known quantity of 10 quarts of fresh Ford oil, and driving as I "normally" would which will hopefully include a session at the local track's road course - monitoring oil usage. I will also have them check for any leaks, such as around the oil pressure sensor.
4. Examining the Blackstone results, conclusions. If they see abnormalities, sharing this with the dealership and put car on oil monitoring program
5. If the Blackstone report is good, resuming my enjoyment of the car plus considering some power mods...

 

[JAJ]

...Rightly or wrongly, the oil utilization of this FPC engine is a continuing major topic on these forums.

[...]

the hot oil reading was mid-way between the two dipstick holes. I also realized there was (now) noticeable soot inside the four exhausts, mostly the inner two pipes.
[...]

I am just under 1000 miles. I drove the car pretty gently in the first 500 miles, a few brief runs up to 6k RPMs from 500 to 700 miles. From 700 to about 825 miles, several wots, several shifts at 8250 rpm. When I returned from that run, hot oil level was 1/8 inch above bottom hole. And Ford sez this is "ok."
5. Today, knocked out about 150 more miles, mostly highway, rarely ever going more that 4k rpm, mostly cruising in 5th at 80 mph. very limited decelerations using engine. Hot oil reading is still above bottom hole by maybe 1/16th of an inch and Ford sez this is "ok."

Do I have an oil usage problem? Maybe and maybe not.

...

You probably don't have a problem. Dark exhaust pipes come from a variety of things, and it's usually from fuel, not oil. Cold starts pump a lot of fuel through to light off the cats, so that could be part of it, or even all of it. Most new cars, including those that use no oil between changes, have dark exhaust pipes.

Your break-in cycle has been well managed. You're seeing a bit of consumption, and that might continue and it might not. My experience of Ford engines in the past is that they break-in for about 10,000 miles. My current GT350 has 7,000 miles on it and it's using a bit of oil. I check it once in a while, but it's not a problem.

I did the oil analysis thing for about 15 years and eventually concluded that it didn't really tell me anything useful. The analysis tools evaluate the condition of the oil, not the engine, so doing a test at 1,000 miles isn't particularly instructive. It'll show that the oil is new and that it's got break-in stuff and gasket sealants drifting around in it, but it won't tell you anything about the engine. I'm not trying to talk you out of it, just telling you in advance what the analysis will say.

So, if you're changing the oil at 1,000 miles or so, then run it out to 5,000 before the next one and watch where the consumption goes. If there's a problem, it'll get worse. If not, it'll get better or stay the same. As far as oil changes go, these engines have a lot of oil in them, so unless you're tracking it heavily, you don't need to change it more often than the OLM says to. I do mine once a year in the fall then park it for the winter.

 

[MAV]

I understand about the need to check the oil in these cars, I really do. But seriously, don't worry about the oil level until it gets below the bottom hole. Don't measure oil in ounces and add a few here or there. Watch the level and if/when gets a quart low, add a quart.

It's got 10 quarts in it from the factory or from your last oil change. A quart low isn't going to hurt it.

 

[GT_Dave]

I understand about the need to check the oil in these cars, I really do. But seriously, don't worry about the oil level until it gets below the bottom hole. Don't measure oil in ounces and add a few here or there. Watch the level and if/when gets a quart low, add a quart.

It's got 10 quarts in it from the factory or from your last oil change. A quart low isn't going to hurt it.

+1 . . . 2 quarts low is OK unless you plan to race the car, you will still have 60% more oil than most of the V8 cars on the road.

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