1987 150 HP V6 'Cooling Issues?' Update!

[mxzeatr]

Here is my previous thread.

http://forums.iboats.com/showthread.php?t=404445&highlight=mxzeatr

Finally got it in the water tonight.

Started the boat up in the water. Had a good tell tale stream and everything looked good. Checked out my new water pressure gauge and I had about 10psi at idle. Way to high right???

So off we went. Nice idle section about 1/4 mile long before you can make a wake. Hit the throttle and jumped it up on plane and it heated right up on the gauge. Had a very nice tell tale stream (water was not that hot comming out on my hand), then I turned around and shut it down. Grabbed two new thermostats and installed those thinking it may have helped. Threw it back in the lake and it didn't change a thing. I did run the boat for a few hours, gauge would go up to 3/4 and stay there while on plane at WOT. Gauge seems to work ok, but I have no idea what the marks mean, the H on it, isn't even red, I'm getting no over-heat alarm, and the horn does the self test, and beeps every now and then for oil, which I can't seem to figure out yet.

I do not have a manual for testing the temp sender for gauge and horn, but I'd like to know the procedure. I can't find a merc manual online or locally, so I'm at a loss there.

The oil alarm came on twice for about 10 seconds (about 2hrs apart) and shut right off. Motor tank is full, other tank is 3/4 full, am I losing pressure somewhere? I have to open the cap on the big tank in the morning and see if there is a pressure loss.

Thanks for any help. Love the info/members in this forum. Lots of knowledge.

-Eric

 

[nbnewbie]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

i didn't see your first post but there's no mention of the poppet valve in this one have you looked there for your problem

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

The link to my first post is above.

Thats what I'm wondering/looking for info on. I mean its the only thing in the cooling system that I have yet to replace, so I'm thinking of just doing it for peace of mind?

Would a screwed up poppit show me high waterpressure at idle and keep the motor hot at higher RPMs?

 

[Faztbullet]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

There is no minium water pressure spec for that year engine but it should be 15-22 psi @5000 rpm. It sounds as if engine cooling is ok and if beeps are occuring when you plane offor hit rough water the oil tank above carbs may need to be bled of air.

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

Thanks for the post.

I am going to replace/rebuild poppit today just to be sure its functioing correctly.

The only thing that has me concerned about the cooling is the temp on the gauge, and I have no idea if this is reading correctly or not, but so long as I'm not getting an overheat alarm I guess I will just see how it goes.


The oil alarm is weird. I've read it could be a misfire? There is a green wire hooked up to the wire on the switch box (I think thats where its hooked) thats shared with the #2 wire comming from the coil. I'm thinking of moving the green wire comming from the alarm modual to the #4 cylinder and seeing what that does for me (if anything).

It did use oil on our trip, I marked the tank, the oil tank under the motor cover was full.

I just finished taking the oil pump out and rotating the motor while looking at the plastic gear on the crank. All is fine there (thank god!).

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

Well the pressure seems fine now that the poppit has been rebuilt. It was missing a gasket, and there was a hole in the diaphram. So thats all fixed and it seems to be running just fine in the driveway.

The oil issue...Well the pump gear is fine (like above), but I did find the oil line from the pump to the fuel line was cracked open, the one from the tank to the pump was even very brittle and cracked around the zip tie clamp. So all of that got replaced, along with another couple sections of lines in the motor. I have a feeling I was getting air in the oil system somewhere.

I have mixed the tank 75:1 (I can see the oil pump working when idling and revving (clearish/green lines)). So I think I'm getting somewhere, if the alarm comes back and I'm using oil, I'll go thru the proper tests on the alarms etc...

 

[j_martin]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

Well the pressure seems fine now that the poppit has been rebuilt. It was missing a gasket, and there was a hole in the diaphram. So thats all fixed and it seems to be running just fine in the driveway.

The oil issue...Well the pump gear is fine (like above), but I did find the oil line from the pump to the fuel line was cracked open, the one from the tank to the pump was even very brittle and cracked around the zip tie clamp. So all of that got replaced, along with another couple sections of lines in the motor. I have a feeling I was getting air in the oil system somewhere.

I have mixed the tank 75:1 (I can see the oil pump working when idling and revving (clearish/green lines)). So I think I'm getting somewhere, if the alarm comes back and I'm using oil, I'll go thru the proper tests on the alarms etc...

Have you bled the bubble off the engine oil tank? That's done by idling the engine (on muffs is fine) and crack the cap slightly till it overflows, then snug it down. Don't get carried away tightening it, they break too easily.

hope it helps
John

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

John,

I did bleed the bubble out the level rose from 1/2" below the neck to full in about a minute, maybe a bit more. Then we bled the oil pump. Every time we loosen the screw oil comes out very good. The line from the pump to the brass fitting (gas line?) about 2" long, is NOT full of oil, but you can see it go down and fill back up when revving the engine. I could not see inside the line before, so I don't know how it was. Does this sound normal?

I ran the boat for about 3 minutes tonight, and no oil alarm. I sure hope I've got both my issues 'licked', I'm ready for 4 days of boating next weekend! Just got done waxing the boat!

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

Ran the boat for another few minutes today. Added oil into the tank (couldn't get it to a low enough ratio as the gas tank was really full, so will add more when I run it a while).

Still no alarm. Hopefully its A'OK.

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

Another day another 'run' in the driveway.

When I started it today, I noticed that the tank on the motor was about 1/2" down, so I lifted the cap and let it over fill once again, then let the motor run for a while until it was 'warmed up' a good bit. The oil line from the pump into the fuel line is still not 'full' back up to the pump, but if you pinch it quick, oil will back up, so it is pumping, I just find it odd that, that line is NOT full. Maybe I'm worrying or questioning over nothing. I would bet that the fuel in the tank is near the 80:1 point. I plan on adding a bit more oil to the tank once there is room for it. Its smoking like crazy out the prop now, so its def. getting oil.

Any input????

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

Here is a picture of what I described in my above post.

 

[j_martin]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

It probably doesn't hurt to have a bit of air in the oil delivery line, but it isn't normal. If you squeeze the primer bulb, then bleed the oil pump, the gas should push the air bubble out the bleed fitting.

It is not normal for any air to get into the engine tank. The only way it gets there is if oil is not delivered from the boat tank, and the pump pulls air in at the check valve just before the engine oil tank. It could be a plugged pickup in the boat oil tank, a pinched or defective oil line, a hole in the air line from the engine, or a defective check valve on the engine.

Intermittent oil delivery could be something floating around in the boat oil tank. Last time I dealt with it, I filtered all the oil in that tank and found a foil seal from an oil bottle.

hope it helps
John

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

John,

Thanks again for your help.

I will pump the bulb and and bleed the oil pump a few times when I get back from a work training this week.

I've cleaned the pickup in the oil tank, and tried to make sure that both caps were installed properly. I don't get why they don't have rubber seals? Oily plastic on plastic can't be the best thing for making an air tight seal I could imagine. I've checked for cracks etc in either tank, and they 'look' ok. The lines from the motor to the tank are un-obstructed, so nothing sitting on them, and I've felt around the 'check valve' (the oil air line hooks to the block, and it looks like a 1" nut with a hose fitting?) and its not leaking anywhere there. Hopefully I get this figured out, its kind of annoying.

 

[j_martin]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

John,

Thanks again for your help.

I will pump the bulb and and bleed the oil pump a few times when I get back from a work training this week.

I've cleaned the pickup in the oil tank, and tried to make sure that both caps were installed properly. I don't get why they don't have rubber seals? Oily plastic on plastic can't be the best thing for making an air tight seal I could imagine. I've checked for cracks etc in either tank, and they 'look' ok. The lines from the motor to the tank are un-obstructed, so nothing sitting on them, and I've felt around the 'check valve' (the oil air line hooks to the block, and it looks like a 1" nut with a hose fitting?) and its not leaking anywhere there. Hopefully I get this figured out, its kind of annoying.

It isn't just a hose barb. It is a check valve and a pressure regulator and a bleed down. All functions must work right.

Run the engine a minute or 2, then shut it down and immediately loosen the filler cap on the boat tank. It should let off a bit of pressure. If it doesn't (I suspect it won't) then the check valve is bad.

hope it helps
John

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

John,

Thank you again!! You have no idea how much it helps a ton for sure!!!

My dealer has one in stock so my brother is going to grab it for me. I'll put it in on Friday am. Anything special I need to do to ensure that the process goes smoothly??

 

[j_martin]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

John,

Thank you again!! You have no idea how much it helps a ton for sure!!!

My dealer has one in stock so my brother is going to grab it for me. I'll put it in on Friday am. Anything special I need to do to ensure that the process goes smoothly??

Use a box end wrench rather than a pliers.

 

[Faztbullet]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

I don't get why they don't have rubber seals?

There are o-ring seals under the caps, they are #32 and 18 in link below and if missing tank will not hold pressure...

http://www.mercruiserparts.com/Show...r=556&bnbr=300&bdesc=OIL+INJECTION+COMPONENTS

 

[j_martin]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

there are o-ring seals under the caps, they are #32 and 18 in link below and if missing tank will not hold pressure...

http://www.mercruiserparts.com/show...r=556&bnbr=300&bdesc=oil+injection+components

bingo:d

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

Well that would explain a lot for sure! I know there is no oring on the fill cap. Can't remember on the other one, but will see about getting those too.

Do they seal on the chamfered part of the tank/cap??

 

[mxzeatr]

Re: 1987 150 HP V6 'Cooling Issues?' Update!

Finnally got link to open.

I dont think they are there...Is the fill cap supposed to be 2 pieces? {'ll see about replacing them even if they aren't there.

Thanks guys!!!