Can't get oil pressure after an oil change

[garycinn]

Time for a mid-season oil change. Came back from the lake Sat and drained oil. Today, put new filter on and filled crankcase with oil. Did not prefill filter with oil (it is ugly since it is upside down). The oil shows on the dipstick as about a half quart high because there is no oil in the filter.<br /><br />Didn't bother to put on muffs. Took to lake today to take the kids tubing. Engine starts, eyes on oil press gauge, no pressure, warning system beeps after 10 seconds, shut it off.<br /><br />Try it again, same thing. I could hear the top end clattering. Shut it off. Winch it back up and take it home.<br /><br />Took off the oil filter -- bone dry. no oil even in the remote oil filter housing (the little bowl).<br /><br />I am absolutely stumped. I thought I was getting pretty good with my wrenching, but I can't do an oil change now?<br /><br />Details: '01 Merc 4.3L V6 with TBI and remote oil filter and thru transom drain.<br /><br />Help?!!

 

[Dunaruna]

Re: Can't get oil pressure after an oil change

Problem with the filters' bypass or drainback <br />valve?<br /><br />Aldo

 

[garycinn]

Re: Can't get oil pressure after an oil change

The only this is that the bypass is in the block and I can't imagine the anti-drainback rubber flap holding back an oil pump.<br /><br />Is there a connection to the oil pump that I could have disturbed during the filter change?

 

[Dunaruna]

Re: Can't get oil pressure after an oil change

I'm pretty sure most oil filters these days have a bypass & anti-drainback valves built in, maybe someone else can chime in on this.<br /><br />The only other thing I can think of is that the oil is to thick.<br /><br />Aldo

 

[garycinn]

Re: Can't get oil pressure after an oil change

It looks like my problem was not filling the crankcase immediately after draining and the pump lost its prime. I'll check this out and post.<br /><br /> http://www.hastingsfilter.com/engineering/tsb_93-1.html

 

[Wart T]

Re: Can't get oil pressure after an oil change

Let us know. I have never seen that 'loss of prime' and I have changed oil in thousands of engines.

 

[Lou C]

Re: Can't get oil pressure after an oil change

Hmm maybe because with the thru the transom drain you can get just about all of it out, whereas with the suction up the dipstick method you usually don't get the very last bit out of it. Perhaps this in combination with the remote oil filter lines draining caused the loss of prime.<br />I'd try filling up the oil filter (trying not to make a mess!) and disabling the igition. Then crank the engine in 10 sec bursts, allowing the starter to cool in between attempts, until you see some movement on the dash guage. You might want to have a spare charged battery since this could kill the batt.

 

[garycinn]

Re: Can't get oil pressure after an oil change

Lou,<br /><br />Thanks for the tips. I am also going to pour oil down the center oil filter mount tube. I think if I prefill the filter, put my finger over the outlet hole, turn it upside down and quickly get it on the mount, I should keep the mess down.<br /><br />The joys of owning a boat.

 

[f_inscreenname]

Re: Can't get oil pressure after an oil change

The oil pump shouldn't have to be primed. If that was the case Jiffy Lube would have been out of business a long time ago. Sounds like the is a air leak in the system some where.

 

[Lou C]

Re: Can't get oil pressure after an oil change

It might be tough if the filter mounts upside down, to do it without making a huge mess in the bilge. I am not familiar with the Merc remote adapter/lines (I still scrunch down to change it the old fashioned way!) Did you ever have issues with the oil pressure on any previous changes?<br />That is a basically new boat, but I wonder if there could be an issue with the oil pick up tube in the pan. I have heard on certain engines of them loosening and causing a drop in pressure, but on an engine that new it seems unlikely. Are you sure the line going from the engine mount to the filter is not blocked (you said the filter was bone dry). Another test might be to try several attempts to prime the motor and then remove the filter to see if it is pumping the oil through. Just get plenty of the oil soak up pads for this one!<br /><br />Another thought, since you say the filter mounts upside down, then the filter mount must be right side up. If you can figure out which hole in the mount feeds oil back to the engine, and fill that line up with oil, maybe that will be enough to purge the air out of that line and allow it to pump. This all kind of reminds me of the trouble you can have with those oil changer pumps when they lose their prime.

 

[Wart T]

Re: Can't get oil pressure after an oil change

I really doubt it's the upside down filter causing problems. Try priming by pouring oil down the filter adaptor first. I wouldnt fill the filter yet. I have seen pick up tubes crack. You DID verify oil on the dipstick didnt you? I've seen techs pour oil in and start up without realizing they left out the drain plug.

 

[garycinn]

Re: Can't get oil pressure after an oil change

I called my Bryant dealer today. He said that with the new drain hoses and extended drains (over a day or so) the pump can loose its prime. He has had his Merc area rep talk to him about this. He said to go about it the way I was approaching it.<br /><br />I re-read the hastings bulletin. It said to fill the inlet hole to the side of the filter mount. That made perfect sense since that tube comes from the pump.<br /><br />I took an old fashioned oil squirt can and filled it with 4oz of my clean engine oil and squirted the oil down this tube. Put on a dry filter, cranked the starter for 10 seconds with the safety cord in the off position, then turned on the safety switch, and let her crank. After she fired up I kept my eye peeled on the oil pressure gauge. In 5 seconds she got pressure!<br /><br />I didn't bother prefilling the filter because if the pump got primed with the oil coming down the tube I knew it would get filled sooner or later.<br /><br />This is the second (and only two) problems I have had with this boat and they were both related to sucking air. The first one was after I ran out of gas. The fuel pump wouldn't prime until I filled up the F/S with gas.<br /><br />Moral of the story: refill in an hour or so (don't wait 24 hours like I did) with the hose drains. If you do, fill the inlet hose to the oil filter mount with oil before mounting the filter.<br /><br />p.s. the GM filters for these engines don't have by-pass valves -- just antidrain back valves: http://www.oilfilterstudy.com/mercruiser.htm

 

[garycinn]

Re: Can't get oil pressure after an oil change

Originally posted by Lou C:<br /> Another thought, since you say the filter mounts upside down, then the filter mount must be right side up. If you can figure out which hole in the mount feeds oil back to the engine, and fill that line up with oil, maybe that will be enough to purge the air out of that line and allow it to pump. This all kind of reminds me of the trouble you can have with those oil changer pumps when they lose their prime.

Lou, you were exactly right. The center tube on the remote mount goes away from the filter, the one on the side comes to the filter. That was the one I filled. Since the mount was facing up, it was easy to do.

 

[Lou C]

Re: Can't get oil pressure after an oil change

Glad to hear it's all better. Not seeing oil pressure after an oil change is not a happy thing.<br />We all have things like this happen.<br />Like the time I was running the engine on the hose (winterizing) and unbeknownst to me, my wife runs the wash. Yep started to overheat, wound up changing the impeller. Now my wife knows when she hears that inboard boat noise in the driveway, no one is even allowed to flush a toilet!!

 

[DJ]

Re: Can't get oil pressure after an oil change

Gary,<br /><br />What a pain!<br /><br />Most "remote" filters I have seen put the filter in a mounting end "up" position.<br /><br />What a lessen!