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Oil change issue, Merc 4.3L

V

vnk

New member
Hello,
Last fall I got a 1999 Capri 1850 with 4.3L Merc.

Trying to change engine oil and got an issue. Before changing the oil I saw the level on the dipstick is above full. ok, I pumped out the oil (warm engine), Waited some time to let the rest oil get down. Few more moments with pump. Great, empty. Strange, overall I pumped out like 2-2.5L of oil??? Changed the filter. added fresh oil, approx 2L, checking dipstick - above level. WTF??? waited, check again - too much. Pumping out "fresh" oil. Coming out like 2L of oil. Oil is dirty. Not as the old one, but not as clear as I would expect. inserting dipstick no oil inside. poor back in the same 2-2.5L - over the level. Found spec for the dipstick - length is correct.

Does someone have an idea of what is happening? I am not a mechanic, but stuff like oil change and other basic services for my previous bot, cars etc I've been doing all my life.

Thank you



 
If my conversion is correct,

2 liters Equals ~ 2.11 Quarts.

A typical V6 holds ~ 4.5 quarts with filter = ~4.3 liters with filter

It sounds to me that you are not getting all the oil out correctly.

What method are you using
 
kghost said:
If my conversion is correct,

2 liters Equals ~ 2.11 Quarts.

A typical V6 holds ~ 4.5 quarts with filter = ~4.3 liters with filter

It sounds to me that you are not getting all the oil out correctly.

What method are you using
Click to expand...
Electrical pump. I can assume pump is not good, but there is nothing at the bottom of the stick or the nylon tube I use to pump out oil. the very bottom tip of the tube is getting dirty in oil, there is no oil in the dipstick pipe.
 
The dip stick has a garden hos thereded fitting on it.
It is designed for a hand pump.

Maybe purchase a hand pump and see if you can get any more oil out.

The dip stick TUBE is ~ 1/4 inch off the bottom of the oil pan. It gets 99% of the oil out that way.

My assumption is the oil pump tube you are using isnt getting to the correct depth. You can always (if easily accessible) remove the oil pan drain plug and be absolutely sure all the oil is drained.
 
kghost said:
The dip stick has a garden hos thereded fitting on it.
It is designed for a hand pump.

Maybe purchase a hand pump and see if you can get any more oil out.

The dip stick TUBE is ~ 1/4 inch off the bottom of the oil pan. It gets 99% of the oil out that way.

My assumption is the oil pump tube you are using isnt getting to the correct depth. You can always (if easily accessible) remove the oil pan drain plug and be absolutely sure all the oil is drained.
Click to expand...

Agree, 99% would be acceptable, not a surgery room:)
But my concern is the "difference" between 99% and 50%.
I am almost sure that the pumping out is the most likely gives me close to 99%.
It is a first time I am touching this engine (purchased it in last fall). Is it possible the previous owner did not changed oil as expected and with years it build inside sort of hard residue in the bottom? Is it possible or not? I did a drive test in the fall, was getting above 4k rpm, oil pressure looks fine and did a compression test.
 
With todays oil, sludge is very UNlikely.

Confirm dipstick tube where it is in the engine block is all the way in. The tube typically has a small flange that will sit on the block casting, flush.
If the tube was messed with or came loose it could be up higher than it should be.
If this is the case, that could explain why you might not be seeing issues.
 
I’ve had the same issue changing oil and filter on my 4.3L Mercruiser. Warmed the engine and left it for 10 mins. Checked the dipstick and it was just above full. Sucked the oil out and with the oil in the filter it amounted to around 2.5L. Did you find out why there was so little?
 
vnk said:
Hello,
Last fall I got a 1999 Capri 1850 with 4.3L Merc.

Trying to change engine oil and got an issue. Before changing the oil I saw the level on the dipstick is above full. ok, I pumped out the oil (warm engine), Waited some time to let the rest oil get down. Few more moments with pump. Great, empty. Strange, overall I pumped out like 2-2.5L of oil??? Changed the filter. added fresh oil, approx 2L, checking dipstick - above level. WTF??? waited, check again - too much. Pumping out "fresh" oil. Coming out like 2L of oil. Oil is dirty. Not as the old one, but not as clear as I would expect. inserting dipstick no oil inside. poor back in the same 2-2.5L - over the level. Found spec for the dipstick - length is correct.

Does someone have an idea of what is happening? I am not a mechanic, but stuff like oil change and other basic services for my previous bot, cars etc I've been doing all my life.

Thank you
Click to expand...
I’ve had the same issue changing oil and filter on my 4.3L Mercruiser. Warmed the engine and left it for 10 mins. Checked the dipstick and it was just above full. Sucked the oil out and with the oil in the filter it amounted to around 2.5L. Did you find out why there was so little?
 
My 2004 4.3L is fitted with the oil drain hose (that can exit through the transom), should that drain 99.9% of the oil from the engine? I've just drained my engine via that method and gave it a new filter, but when I added only 4 Litres in, this has taken it above the mark already. It's supposed to take 4.3 Litres. I can only think that some oil was left in the sump area and that I should drain some out to get back to level.
 
_jp said:
My 2004 4.3L is fitted with the oil drain hose (that can exit through the transom), should that drain 99.9% of the oil from the engine? I've just drained my engine via that method and gave it a new filter, but when I added only 4 Litres in, this has taken it above the mark already. It's supposed to take 4.3 Litres. I can only think that some oil was left in the sump area and that I should drain some out to get back to level.
Click to expand...
Really, I’ve never seen an oil drain line before. Check your engine serial number online. Some 4.3L engines have a 3.8l oil capacity
 
Very common on Inboard Ski boats as there is typically a large drain plug thru hull below engine or very close proximaty to the engine.

Most likely original owner ask to have it installed.

They work good but take a long time especially if oil is cold.

The oil dip stick tube if original should have a garden hose threaded male on it near top. they make/sell hand pumps that connect there. Also an OEM dip stick tube goes all the way down into oil pan about 1/4 inch from bottom.
 
vnk said:
Electrical pump. I can assume pump is not good, but there is nothing at the bottom of the stick or the nylon tube I use to pump out oil. the very bottom tip of the tube is getting dirty in oil, there is no oil in the dipstick pipe.
Click to expand...

Does that pump have a flexible plastic tube? Place it next to the dipstick tube and when the end reaches the bottom of the pan, mark the top of the tube- it's easy for the tube to reach the bottom of the pan and curl up, so it misses a fair amount of oil. OTOH, I can't explain why you removed more than 4 Liters- are you sure the dipstick is correct?

WRT the drain hose- a pump can be used with that, too- push the tube in until it stops and pull it back about an inch- that removes more than any other method.

I worked on boats for several years and would never use gravity- it's a colossal waste of time but then, I was on the clock and couldn't wait because I had a lot of boats waiting for their oil change but even for my own boat, I don't want to waste time. Sure, there's always something else that's needed, but waiting isn't one of them.

Dip the tube into the waste oil and try the pump- if it's moving oil, it's working. If the end of the tube is cut straight across, cut it at a slight angle.
 
_jp said:
My 2004 4.3L is fitted with the oil drain hose (that can exit through the transom), should that drain 99.9% of the oil from the engine? I've just drained my engine via that method and gave it a new filter, but when I added only 4 Litres in, this has taken it above the mark already. It's supposed to take 4.3 Litres. I can only think that some oil was left in the sump area and that I should drain some out to get back to level.
Click to expand...
Did you check oil level before or after running?

The drain pug in oil pan should drain all the oil out of the pan.
Several factors could alter that.
Boat angle not allowing oil to go to drain plug
Drained as soon as shutting down engine and not all oil drained back into pan
 
jimn said:
Does that pump have a flexible plastic tube? Place it next to the dipstick tube and when the end reaches the bottom of the pan, mark the top of the tube- it's easy for the tube to reach the bottom of the pan and curl up, so it misses a fair amount of oil. OTOH, I can't explain why you removed more than 4 Liters- are you sure the dipstick is correct?

WRT the drain hose- a pump can be used with that, too- push the tube in until it stops and pull it back about an inch- that removes more than any other method.

I worked on boats for several years and would never use gravity- it's a colossal waste of time but then, I was on the clock and couldn't wait because I had a lot of boats waiting for their oil change but even for my own boat, I don't want to waste time. Sure, there's always something else that's needed, but waiting isn't one of them.

Dip the tube into the waste oil and try the pump- if it's moving oil, it's working. If the end of the tube is cut straight across, cut it at a slight angle.
Click to expand...
You need to read the date of the post you responded to. The guy JP piggybacked this post from 2019 vs starting his own post
 
kghost said:
Did you check oil level before or after running?

The drain pug in oil pan should drain all the oil out of the pan.
Several factors could alter that.
Boat angle not allowing oil to go to drain plug
Drained as soon as shutting down engine and not all oil drained back into pan
Click to expand...
I actually checked it both ways @kghost; it was higher before I ran it up (but presumed the new filter would take some), I just checked it again today and it's still a bit above the line (that's with 4 Litre can), an additional 0.3 Litres is certainly not needed at the moment. The Mercury Mercruiser manual I have states 4.3L, I'll try looking up the serial number to see if it says different @GMcInroy.

I did level the boat as much as possible to check the oil level. But, I have jacked the hitch up and down several times and I don't remember if I had it jacked up when draining... So that could be one silly mistake I'll remember for next time 🤦‍♂️.

I hadn't managed to start the engine before draining (because of the fuel getting in to the sump from the carb flooding). I just opened the oil cap for air and the drain plug and then left it 24 hours to "fully drain" - nothing was coming any more. The oil filter was removed the next day (after a mission trying to get that undone!).

Picture of drain line for @GMcInroy reference

IMG_2736-min.JPG
 
_jp said:
I actually checked it both ways @kghost; it was higher before I ran it up (but presumed the new filter would take some), I just checked it again today and it's still a bit above the line (that's with 4 Litre can), an additional 0.3 Litres is certainly not needed at the moment. The Mercury Mercruiser manual I have states 4.3L, I'll try looking up the serial number to see if it says different @GMcInroy.

I did level the boat as much as possible to check the oil level. But, I have jacked the hitch up and down several times and I don't remember if I had it jacked up when draining... So that could be one silly mistake I'll remember for next time 🤦‍♂️.

I hadn't managed to start the engine before draining (because of the fuel getting in to the sump from the carb flooding). I just opened the oil cap for air and the drain plug and then left it 24 hours to "fully drain" - nothing was coming any more. The oil filter was removed the next day (after a mission trying to get that undone!).

Picture of drain line for @GMcInroy reference

View attachment 36335
Click to expand...
IMG_6926.png
The newer 4.3L from 2002 onwards are 3.8litre capacity engines. Handy drain point!
 
GMcInroy said:
Really, I’ve never seen an oil drain line before. Check your engine serial number online. Some 4.3L engines have a 3.8l oil capacity
Click to expand...
My buddy has that same engine, on a 20’ Stingray kept at my dock. He used a brass hand pump I had, one that screws into the dipstick top. It works great, especially with the engine warmed up, but we both didn’t like how messy the pump was once disconnected. Unless flushed with gas or varsol, it dripped forever.
He made up a permanent tube that sits in the bilge. Feed it out the transom drain, open it & oil (if warm), drains quite quickly.
I use a vacumn extractor, fed down the dipstick tube. As long as oil is warm, it only takes about 3-5 minutes. The first time I used it I also worked a pan into the bilge & undid the drain plug. Very little came out. You can feel the tube hit bottom of the pan. Don’t force it any further & you’ll get 99% of the oil.
 
I have used the vacuum extractor with both the thin tube down the dipstick tube and the garden hose that connects to threads on top & the garden hose adapter works a lot better; larger diameter for better flow….
 
The other advantage of the vacumn extractor, at least on my Volvo powered boat…the oil filter is horizontal, & almost no room to get anything under except a plastic bag.
I punch a hole into the filter & jam a screwdriver down through the filter media til it hits bottom. The extractor will then suck almost all oil out of the filter, leaving only an ounce or so to catch with the plastic bag.
 
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