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New rebuilt engine blows out oil filter gasket.

markbabb

markbabb

Contributing Member
I am really puzzle why this newly rebuilt engine would blow out the filter gasket. I have turned it hand tight and there is nothing in the way of it making contact with the mounting surface. Does anyone know of a reason this would occur? Could it have that much oil pressure to blow it out. I was told that the oil filter for a 350 Mercruiser or any SB chevy engine has not changed for 1970-90 something. I bought Fram filters and 2 have blown out the gasket. This engine is a one piece rear seal so i know it is a 80 something model. It runs and sound good but it keeps blowing out the oil. Help!
 
Sounds like a pressure regulator (by- pass as Bt Doctur calls it) problem. What is the oil pressure range from idle to WOT?
 
tugwood said:
Sounds like a pressure regulator (by- pass as Bt Doctur calls it) problem. What is the oil pressure range from idle to WOT?
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I don't know the pressure ranges as the oil pressure gauge is not reading at all. As soon as I start it with oil in it it blows out the oil from the filter. Ok, so if it is the oil pump itself that means pull the motor back out to check. Anything else you can think of and why would the pressure regulator go bad, I have never heard of that happening.
 
It would make more sense to buy a relatively cheap manual pressure gauge with same size thread as the sender unit on your engine and have a look. Pulling an engine is a whole lot of work and things need to be verified first. 0 to 125 will cover the possible pressure range. Also if possible take a valve cover off to make sure oil is reaching the top end. No oil would indicate a main gallery is blocked. Checking the filter housing gasket to block would be a first step if no or little oil is reaching the top end. Also you will find little oil pressure on that gauge you are going to go buy now. I am not an expert on gas marine engines however I am a 30 year veteran marine engineer most familiar with slow to medium speed large bore diesel engines. I find the range of advice on this forum to be from dangerous and ridiculous to extremely knowledgeable and helpful.
 
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tugwood said:
It would make more sense to buy a relatively cheap manual pressure gauge with same size thread as the sender unit on your engine and have a look. Pulling an engine is a whole lot of work and things need to be verified first. 0 to 125 will cover the possible pressure range. Also if possible take a valve cover off to make sure oil is reaching the top end. No oil would indicate a main gallery is blocked. Checking the filter housing gasket to block would be a first step if no or little oil is reaching the top end. Also you will find little oil pressure on that gauge you are going to go buy now. I am not an expert on gas marine engines however I am a 30 year veteran marine engineer most familiar with slow to medium speed large bore diesel engines. I find the range of advice on this forum to be from dangerous and ridiculous to extremely knowledgeable and helpful.
Click to expand...

I still have the problem of no oil in engine because it gets pumped out by via the constantly blowing out of the filter gasket. I put the filter back on and it blows out so how could I ever have enough pressure to read on the manual gauge you want to see on the engine. The only way the top end is getting oil now would have to be from the oil I dump in the top of the valve covers adding new oil.

Is there any way to remedy the stuck or faulty or missing pressure regulator without replacing the pump by removing the engine again?
 
Neither did I ,but I removed a oil filter from a motor, et it sit over the winter with no filter. When I finally got to start it it kept blowing the gasket out from under
the filter. Replaced the oil pump and everything was fine.
 
Well that is not what anyone wants to hear after just getting it installed, what a pain in the rump. Thanks for the advice even though it is a hard pill to swallow.
 
If you can't run the engine then take the filter housing off as I suggested and make very sure the gasket is correct and there are no blockages. This is the simplest check you can make before more complex actions are taken. Another trick would be to remove the sending unit, install a temporary barbed pipe thread to barb fitting, attach an appropriate size hose to that you will route to the oil fill on the rocker cover. This will show you how much oil flow you have and relieve that excessive pressure if it is in fact going beyond the filter housing... Just check that filter gasket first.
 
Mine was blowing the gasket using the priming tool. Thought i was going to bust the remote oil lines it had so much pressure
 
tugwood said:
If you can't run the engine then take the filter housing off as I suggested and make very sure the gasket is correct and there are no blockages. This is the simplest check you can make before more complex actions are taken. Another trick would be to remove the sending unit, install a temporary barbed pipe thread to barb fitting, attach an appropriate size hose to that you will route to the oil fill on the rocker cover. This will show you how much oil flow you have and relieve that excessive pressure if it is in fact going beyond the filter housing... Just check that filter gasket first.
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Thanks for your replies and help. The gasket mating surface is ok and I found an old pump I had inside, on my bench and I decided to take it apart to see this relief valve . I found it was stuck fast just as the one in the new engine must be. I have tried everything else I can think of ...so I 'm starting over and pulling this engine back out and putting a new pump in. I know like BT doc said this motor sat for a long time with no filter as I waited out winter to be able to finish this project , kudos to BT doc for his spot on knowing the problem right off the bat and if i ever do it again the engine will be tested before I install it. Thanks to you both again.
 
If the filter is remotely located, make sure the lines are not reversed. Some oil filters have a one way valve built into them.
 
The the bt doc's point, I learned the hard way, pulling out the filter and not realizing the filter gasket had stuck on the pump.

i thought there was sometime funny about installing the new filter and how it felt when securing.

It didn't take long to validate as I was pumping more oil out then in the engine.

I now pull any filter out and inspect, to ensure the gasket came off as well before re-installing. Sometimes you have to learn just by doing.
 
All good observations and real experiences. Just to make sure I was not misunderstood what I meant by gasket was not the one on the filter itself but on the filter head if it is not remote mount and is bolted to the engine in way of the main oil gallery. (This from plenty of experiences in my field not just on engines but other machinery where a gasket can be installed incorrectly causing a full or partial blockage) Also If it was me and I suspected a seized pump regulator I would still use the method of relieving the pressure that I suggested. After starting and running a while 2 of the oils functions of cleaning and lubrication along with heat on the valve may be enough to free it up. Fact is the sending unit will have to come off anyway. I am surprised that anyone would have an engine without oil pressure indication especially after having an engine overhauled.
 
tugwood said:
All good observations and real experiences. Just to make sure I was not misunderstood what I meant by gasket was not the one on the filter itself but on the filter head if it is not remote mount and is bolted to the engine in way of the main oil gallery. (This from plenty of experiences in my field not just on engines but other machinery where a gasket can be installed incorrectly causing a full or partial blockage) Also If it was me and I suspected a seized pump regulator I would still use the method of relieving the pressure that I suggested. After starting and running a while 2 of the oils functions of cleaning and lubrication along with heat on the valve may be enough to free it up. Fact is the sending unit will have to come off anyway. I am surprised that anyone would have an engine without oil pressure indication especially after having an engine overhauled.
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New pump installed, old pump relief valve was stuck, engine to go back in boat soon. Thanks for the responses. Wish I had checked it's proper function before I installed the engine, live and learn try to remember all your mistakes. Don't leave engines for too long without proper maintenance and without an oil filter on it. I should have spun the pump and circulated the oil more often. Thanks for the replies.
 
I'm glad that you found the problem.... although quite a bit of work. Bummer!

FYI... the SBC oil pump is capable of up to several hundred PSI.... perhaps even 300-400 psi.
The relief valve is what controls the pressure that the oil journals see.... of which means that the filter cansiter also sees this.


.
 
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I forgot to ask a question about the Alpha 1 stern drive. When I removed it, it had puked the lower unit oil into the bellows. I had recently bought this on the guys word that it had no issues, well I can't go back to him and want to know what are the chances of being able to remedy this replacing the oils seal behind the big castle nut. What else will it entail besides pulling it out replace the seal and put it back together. I know it should be done by a mechanic but I have run out of funds for one. I watched a video of a guy doing it and warning about pre-loading the bearings and using a compression band to load it back into the housing. Any tips on checking the condition of the inside of the housing? Thanks for the help!
 
remove the castle nut, pull out input shaft assembly,remove yoke nut, gear, bearings, pop out old seal from carrier ring, press new one in flush, reasssemble ,tighten yoke nut, reinstall ,tighten castle nut.
Use this seal from any good auto parts house National 712550. Its the oem of 483323VGO
http://www.boatfix.com/merc/Servmanl/6/6A3R3.PDF
 
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Thanks for the reply it's just what I needed to know.
Do you happen to know the torq specs on the yoke and castle nutd ? If not I will look for them.Thank you again for the no BS answer.I feel I can always count on you and a few others for some great advice.Your the man. I got the engine re-installed but didn't start it because I have to figure out a plumbing system to run it without the out drive on. I let you know how it turns out.
 
yoke is 75Ft.lbs for a standard gear set, rolling torque method for newer gears is 4 in/lbs.
If you can remove everything by hand you have the early type,just tighten 75lbs
castle is 200 ft/lbs. All the needed info is in that link

A washing machine hose cut in half and shoved into the water inlet hole
 
I didn't follow the link before I asked. Many thanks. I do have an old house I can use good idea. Crossing my fingers for tomorrow.
 
markbabb said:
I am really puzzle why this newly rebuilt engine would blow out the filter gasket. I have turned it hand tight and there is nothing in the way of it making contact with the mounting surface. Does anyone know of a reason this would occur? Could it have that much oil pressure to blow it out. I was told that the oil filter for a 350 Mercruiser or any SB chevy engine has not changed for 1970-90 something. I bought Fram filters and 2 have blown out the gasket. This engine is a one piece rear seal so i know it is a 80 something model. It runs and sound good but it keeps blowing out the oil. Help!
Click to expand...
I have the same problem. what was the issue?
 
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