This should be simple. But can anyone explain a phenomenon that is occurring when I check my engine oil. This is a Cat D3G 2005. Whenever I do the initial dip stick pull, the stick is dry. I am 60 and sometimes my eyes do not see well up close so I wear readers when I check the oil level. But not just based on vision. I can touch the stick and it is DRY. My initial reaction is to panic! But then, I re-insert the stick and pull it out to find that the level is somewhere above add. This happens whether it sets for a day or an hour. Can anyone explain this. It is not something that happens on the odd ocasion. I check the oil almost everytime I run the machine. It is the rule not the exception. It does not sound possible, does it!
I'm no cat expert but I've seen that on other types of equipment. Usually they have a little bit more blow by then normal and it pushes the dipstick out a little. Try pushing it down hard before you pull it the first time and make sure it is seated solid.
I always make it a habit to hold the stick in for 3 secounds b4 i look at it. I don't know why it'll read low..... something inside the well where it goes i guess.
my guess would be the tube goes past the end of the dipstick... when the dipstick is in the tube.. it's sealed no fluids can enter the tube... pull the dipstick... the seal is broken the fluid enters the tube... like a straw in a cup of pop... hold your finger on the top... insert straw and remove no pop in straw.... no do the same with out you finger on the top of the straw... after you have insert the straw put you finger on top of straw ... and remove... you have now checked your pops level..
OK, I will give it a shot. Basically you have a good tight seal at the handle of your dipstick. When the engine runs, the oil comes out of the tube into the oil pan, then when the engine is shut off the level in the pan rises, but is will not go up the tube because the seal at the top of the dipstick will not allow that air to escape. I would compare it to a bucket of water and then take a glass, turn the glass upside down and push it into the bucket and the water will not enter the glass. Make sense now? Then you pull the dipstick and it allows air to go and then the oil level will rise in the tube.
I thought about that. But not the cause. The dip stick has always been fully seated. In fact the seal is very tight.
I think you and heavylift are on to the same thing. The seal on the stick is tight. When I pull the stick it allows the oil to seek its natural level w/o the pressure of the air that has risen into the tube. I had some feeling for this but you guys put it into words. Thanks. It makes sense now.
I've always pulled the dip stick and wiped and replaced then pulled out to check fluid level. That allows the pressure or vacuum to equalize in the dip stick tube.
On my Komatsu D31, I check the oil and water every day before I start it. The manual calls for checking the oil before startup. It makes no difference whether I read the dipstick when I pull it out 1st thing or read it after I pull, wipe clean and put back in. The reading is the same. Any dozer cost too much to not take 3 minutes to crawl up and check the oil & water. This is cheap insurance against an instant engine job.
Heavylift has the answer.It applies to cars as well.I always restick to bayonet for a true reading.If you are too fast you still may not get the correct reading.I give it 10 seconds or more for good measure.....lol.Ron G
Thanks. I am learning even at 60 years old. It is the spice of life.
if that is the case your PCV valve/Breather tube is plugged Pj