Oil level too high?

Rustychain

Cadet
Joined
Jun 4, 2009
Messages
25
I've been noticing similar thing on my 4.3L. Dipstick has threaded hose coupling at top, and I connect a drill-powered pump to it to drain. Dipstick always reads high.
Dipstick connects to oilpan drain port through a "banjo" fitting at bottom of stick. Next time I am going to crawl down there and remove the banjo fitting and catch the oil in pan and measure amount. If more than 5 qts come out, it will prove how much oil that the dipstick-pump method is leaving in the oilpan.
Update: Removed the banjo fitting at bottom of dipstick to drain oil, and got little over 5.5 qts out. I had never added more than 5 qts when changing oil by sucking up the dipstick tube. Looks like I probably leave some oil in the pan when draining through the dipstick tube. I also assume that I'm burning some amount of oil, but it never shows low on dipstick. Oil was not milky at all, and I let the oil sit in a clear plastic container for a week to see if any water settled out and it did not. Overall, it's probably too much work to get down there to remove the banjo bolt every time, but I may do it every 2nd or 3rd change to get whatever gunk may be sitting at bottom of pan. I'll probably put in less than 5 qts when draining through the tube to account for what's still in the pan. My dipstick had always shown oil level to be high, and it was, so I will believe the marks on the dipstick now.
 

ggc

Cadet
Joined
May 27, 2020
Messages
11
I think it is normal to leave around 1/2 quart in the pan when pumping the oil out, more if not level. Some Oil in the filter too. Now that you have confidence in the dipstick level just add oil until at the full mark.

One thing you might consider if you trailer your boat is to buy an oil drain line kit. It is a hose with a fitting at one end that is permanently threaded into the drain plug on the pan. Pull the hose out the bilge drain and remove the plug at the end of the hose to drain. its an easy oil change that gets all the oil from the pan every time.
 

Rustychain

Cadet
Joined
Jun 4, 2009
Messages
25
I think it is normal to leave around 1/2 quart in the pan when pumping the oil out, more if not level. Some Oil in the filter too. Now that you have confidence in the dipstick level just add oil until at the full mark.

One thing you might consider if you trailer your boat is to buy an oil drain line kit. It is a hose with a fitting at one end that is permanently threaded into the drain plug on the pan. Pull the hose out the bilge drain and remove the plug at the end of the hose to drain. its an easy oil change that gets all the oil from the pan every time.
I wish I could use that type of kit, but there is no other provision for having a dipstick. It is installed by banjo bolt to the oil plug. Unless there is a drain-line kit that takes this into account?
 

Scott Danforth

Grumpy old guy who plays with boats
Joined
Jul 23, 2011
Messages
42,470
I wish I could use that type of kit, but there is no other provision for having a dipstick. It is installed by banjo bolt to the oil plug. Unless there is a drain-line kit that takes this into account?
there are a few kits that have a double outlet adapter
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,175
One thing you might consider if you trailer your boat is to buy an oil drain line kit. It is a hose with a fitting at one end that is permanently threaded into the drain plug on the pan.
Volvo Penta already basically has that. The dipstick tube screws into the drain hole of the pan. You attach a pump to the threaded garden hose fitting at the top of the dipstick tube and you suck all the oil out the bottom of the pan.
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
10,502
My OMC 4.3 uses that exact same dipstick tube to the banjo bolt on the pan as VP used and it never takes as much to read full as the manual lists for the oil capacity. Another oddity I noticed, the oil level on the dipstick is affected by temperature. If it’s right at full when you have the engine warm and then you let it sit a day or two as it cools off the air in the tube contracts & appears to pull the oil up in the dipstick tube showing a false high reading. However if you leave the stick out for a few min & then recheck the level of the oil in the tube equalizes and it will read correctly. Sometimes if you check it after it’s been run with the engine hot the opposite happens with warm air in the tube preventing the level from rising high enough to read correctly on the dipstick. But if you leave the stick out for a few min the the same thing happens the level in the tube equalizes & it will read correctly.
 

Donald0039

Petty Officer 2nd Class
Joined
Jun 11, 2022
Messages
140
No matter how you pump the oil out you will end up with a 1/2 QT of oil remaining.

For my old boat I got a Jabsco oil drain hose that replaced the drain plug and there was a cap on the end of the drain hose. So you pull the drain hose up a bit on the side of the engine unscrew the cap and attach a pump to pump it from the drain plug hole in the oil pan. Or push the hose out the bilge drain hole and unscrew the cap and drain the oil into a pan outside of the boat. Unsure if they they still.sell it.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,175
No matter how you pump the oil out you will end up with a 1/2 QT of oil remaining.
I totally disagree. The oil dipstick actually is connected to the pan drain hole on a Volvo Penta.

Out of curiosity, how do you come up with this 1/2 qt number?
 

Donald0039

Petty Officer 2nd Class
Joined
Jun 11, 2022
Messages
140
I totally disagree. The oil dipstick actually is connected to the pan drain hole on a Volvo Penta.

Out of curiosity, how do you come up with this 1/2 qt number?

This was a general statement for pumping oil from boat engines. In my old Mercruiser 5.7L I pumped the oil via dipstick then put aluminum pan under the drain plug and removed the drain plug to drain the rest and install a Jabsco drain hose for future oil drains. It looked like I got about 1/2 a QT in the aluminum pan.
 

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,175
This was a general statement for pumping oil from boat engines. In my old Mercruiser 5.7L I pumped the oil via dipstick then put aluminum pan under the drain plug and removed the drain plug to drain the rest and install a Jabsco drain hose for future oil drains. It looked like I got about 1/2 a QT in the aluminum pan.
Well...that doesn't apply here since the drain plug is replaced by a banjo bolt and a dipstick tube. You are sucking the oil out of the pan drain hole.
 

Rustychain

Cadet
Joined
Jun 4, 2009
Messages
25
Well...that doesn't apply here since the drain plug is replaced by a banjo bolt and a dipstick tube. You are sucking the oil out of the pan drain hole.
Yes, you are sucking oil out of the drain pan hole, but, as soon as you get close to empty, you start to pull air up the tube, and that loss of suction leaves some oil in the pan. I agree with the estimate of approx 1/2 quart left in pan when pumping it up the dipstick tube.
 
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