cooling system issues on first start of season

[vrvokey]

I have a 1988 celebrity with a merc 5.0 and alpha one drive.So the problem is no water getting to the block or manifolds.I will start from last season, towards the end of last season I installed a new impeller and housing, seemed like she was running a little warmer than normal so I figured it was a good idea to change the impeller,after the change everything worked great,no issues and it run much cooler.When I put the boat in storage, heated shop,I flushed everything out,changed the engine oil and put stabilizer in the fuel and ran it through the carb,the very last thing I did was pull the thermostat housing and filled the block full of antifreeze just to try and prevent corrosion.Now it's time to get ready for another boating season,changed oil in drive cleaned up thermostat housing and installed new thermostat and sleeve,checked all the hoses and clamps everything looked good,hooked up the muffs,turned on the water,then tried to start the engine,it took a couple of tries but started and ran great rite away.Next I checked for water coming from the exhaust ports in the drive,lots of water and looked like the antifreeze was coming out,also the port at the bottom of the drive by the oil drain plug had lots of water coming out,a steady stream.I then headed back to the controls everything was looking good then I noticed the temp gauge slowly creeping up,I thought maybe the thermostat needed to get a little bit hotter to make it open,but the gauge kept on going,no numbers on my gauge,it's digital,it went to one line from the top so I shut her down and let it cool.My first thought was a faulty thermostat so I removed it.When I took the hoses off the thermostat housing I noticed that the hose coming from the drive which I believe is coming from the sea pump to the thermostat housing then the water pump was dry,not even damp.So I'm thinking that the problem is the impeller but I can't figure out how I am getting water through the exhaust ports in the drive without having water in the block or manifolds,and it gets even more confusing,when I open the drain cocks on the manifolds and block I get antifreeze.Could it be that the block is air locked or something,very confused and I would hate to pull the drive apart only to find no issues with the impeller,any suggestions or has any one had this trouble before?

 

[Bondo]

Re: cooling system issues on first start of season

When I took the hoses off the thermostat housing I noticed that the hose coming from the drive which I believe is coming from the sea pump to the thermostat housing then the water pump was dry,not even damp.So I'm thinking that the problem is the impeller but I can't figure out how I am getting water through the exhaust ports in the drive without having water in the block or manifolds,

Ayuh,.... Please use some paragraphs,... That's awfully hard to read with these ole eyes,....

Pull the feed hose comin' from the drive, muff it up, 'n try it to see if there's water comin' from the impeller pump,...

 

[tpenfield]

Re: cooling system issues on first start of season

I have had situations where a new thermostat does not open up right away and causes the engine to overheat a bit on the first startup. Then once it opens, it seems to be fine.
I would check the water coming from the impeller, as Bond-o recommended and then give everything another try. Also, you mentioned a new thermostat sleeve . . .. Make sure that is in correctly and not able to spin around, etc.

 

[vrvokey]

Re: cooling system issues on first start of season

Yeah sorry about the paragraphs after 8 hrs of frustration at 2 am I was lucky I could type at all.
So I'm assuming you mean to do this without running the engine.Should I get water through the hose from just hose pressure?
As for the thermostat,I tested it last night and it opened up fine just before the water started to boil,so that should be rite around 160,and it is a 160 thermostat.
As for the sleeve, the kit I used has a plastic sleeve and it has a tab on the side wich slides into a groove in the thermostat housing,this keeps it from spinning so that should be ok.
Thanks for the info guys,it's great to have a spot where dummies like me can tap into all the infinite wisdom and experiance you guys have,thanks again!!

 

[Eric 3.7LX Alpha 1]

Re: cooling system issues on first start of season

When you do the thermostat test in a pan of water, you have to use a thermometer in the water with it. Otherwise your just guessing as to when it opens.

What brand of impeller did you install?

Below is a post I copy/pasted from Achris on another thread with similar issue:

Do a water flow test.. It's in the manual... With the hose that comes from the transom (goes onto the thermostat housing) disconnected and in a measuring jug, the engine should pump a certain quantity over a 30 second period... I would be doing that as my first test... That would rule out the water pump... If that's ok, start looking for an obstruction somewhere...

I'll look up the data and re-post for you...

Chris.........

Edit: Found it... It's Service Bulletin 82-4. The first one in the Service Bulletin section at the back of service manual# 4...

Boat must be in the water, not on flushers.
Run the engine at EXACTLY 1000rpm for EXACTLY 15seconds.
For a 1.50:1 ratio leg, the output should be 4.0 quarts (3.8litres)
Do the test 4 times...

 

[vrvokey]

Re: cooling system issues on first start of season

I only use genuine Mercruiser parts and I boild it mainly just to make sure it opens.
Is there away to do the test with lower results maybe, on the muffs,the boat is still at the shop and I would like to have everything working befor I try it in the water,maybe thats not the way to go about it,not sure!!!
One thing I forgot to mention in the original post is that I pulled the thermostat and ran it that way just to see if I could get water through the block and still nothing.

 

[Bondo]

Re: cooling system issues on first start of season

I only use genuine Mercruiser parts and I boild it mainly just to make sure it opens.
Is there away to do the test with lower results maybe, on the muffs,the boat is still at the shop and I would like to have everything working befor I try it in the water,maybe thats not the way to go about it,not sure!!!
One thing I forgot to mention in the original post is that I pulled the thermostat and ran it that way just to see if I could get water through the block and still nothing.

Ayuh,... Try it,... atleast you oughta be seein' Water Flow,...

 

[vrvokey]

Re: cooling system issues on first start of season

I'm here racking my brain and just had a thought or a question.
What drives the impeller pump,does it make a difference that I ran it in throttle only in the handle,should it be in nuetral with the throttle only switch out,in the normal position???
Hopefuly I don't sound stupid here,just trying to think of everything possible.

 

[Bondo]

Re: cooling system issues on first start of season

I'm here racking my brain and just had a thought or a question.
What drives the impeller pump,does it make a difference that I ran it in throttle only in the handle,should it be in nuetral with the throttle only switch out,in the normal position???
Hopefuly I don't sound stupid here,just trying to think of everything possible.

Ayuh,... In an Alpha drive, Everything but the prop shaft turns with the motor,...

So,... That ain't yer problem,...

 

[vrvokey]

Re: cooling system issues on first start of season

Ok
Is it ok to put the garden hose in the moter end of the discharge hose and backflush down through the drive?
The reason is our shop is a locomotive and train car repair shop,we run a short line railroad that supplies the local powergenerating stations with coal.
We do alot of car repair,metal fab and when I put the boat away I put the cover on but didn't wrap the drive and that grinding dust and welding smoke has a tendencie to creep into some awfull places.
Just wondering if I should flush the drive through backward just to make sure there's nothing in there?

 

[Eric 3.7LX Alpha 1]

Re: cooling system issues on first start of season

Sure... you can also pull the outdrive off the boat and run a garden hose into the Water inlet opening of the bellhousing (Where the O-ring sits) and run the engine with the drive off. With good water flow (1-gallon in 15-seconds or 4-GPM) the same as the test I posted above your engine should run just fine.

You can test flow from the hose using a 5-gal pail and stopwatch.

 

[vrvokey]

Re: cooling system issues on first start of season

Ok thanks,that gives me some things to try.I will let you guys know how I make out,heading to the shop as a type.

 

[vrvokey]

Re: cooling system issues on first start of season

Ok guys,think I got her figured out,two things I found.
#1 the thermostat is faulty,I checked it again and its not consistant,sometimes 160 sometimes up to 180 before ot opens so I checked the old one,its a 140 its working good sp I put that one back in untill I can get a new one.
#2. Found that the block had some debris in it,flushed it through a few times untill i was getting lots of water from the drain cocks and then filled ot with water intill all the air came out the thermostat hole in the intake.

Shes all back together now and seems to be working good on the muffs.It gets to about 3/4 on the temp gauge and then just goes up and down one line never passing the 3/4 mark.
Next test is in the water, hopefully everthing goes well.
Thanks again for all the help guys I will let you know how it goes.

 

[maicoman]

Re: cooling system issues on first start of season

Excuse the pun here but muffs and boats shouldnt go together.I dont know why more experianced boaters don't help by saying cut a stupid garbage can in half and drop the leg in the water.The quality of most look straight out of a JC Whitney catalog.Talk about the first online crap part store.Impellers cant push air and water,sink it to test it.