Diagnostic Help with Mercrusier 165 inline 6

[michaelbluewolf]

Hello and thanks to all that respond,
My 1970 Sea Ray SRV 190 Has a Mercrusier 165 inline 6 that I installed in place of a GM truck engine the previous owner had installed the boat. This engine[sic] was used in salt water for a few years. I am having a problem with water in the # 6 cylinder, The engine sat all winter after I installed in here in North Cakalaky last fall. I engine was dry when I checked it and hooked it up to the hose with a flush tee in the raw water feed hose to the thermostat housing and let the water run till it ran out the outdrive. I removed all sparkplugs and shot so penetrating oil in all the cylinders. with the plug out I manually turn over the engine at the crank. The rear cylinder shot a geyser of water out of the boat. I inspected the lower port side of the engine forvisable crack[ as I had done when I purchased the engine used] I see no external cracks in the block, I have only minor signs of water in the oil. In other words the oil in new and only a 1/4 inch over the full line on the stick. I had previously ran the engine for 10 minutes last fall after installation. I stop when I heard the engine was hydralocking and stopped and put the boat to up till now. I know we had some 100 Degree day last september and most of the water should have evaporated.
My question is do these manifolds suffer from corrosion and deteriation. I also am curious as to what I should be looking for when I take the manifold off. I want to make sure and do a complete diagnosis.
My wife is still saying...... spend 800.00 on that boat and still haven't been in the water yet. LOL
Thanks Again, Mike

 

[Bondo]

Re: Diagnostic Help with Mercrusier 165 inline 6

My question is do these manifolds suffer from corrosion and deteriation. I also am curious as to what I should be looking for when I take the manifold off. I want to make sure and do a complete diagnosis.

Ayuh,... They usually fail at the manifold/ riser connection,... Take it apart, 'n look there...

 

[Don S]

Re: Diagnostic Help with Mercrusier 165 inline 6

Pull the riser off the manifold. Clean the gasket surfaces to clean shiny metal and post a picture of each.
http://forums.iboats.com/showthread.php?t=468676

 

[ziggy]

Re: Diagnostic Help with Mercrusier 165 inline 6

I removed all sparkplugs and shot so penetrating oil in all the cylinders. with the plug out I manually turn over the engine at the crank. The rear cylinder shot a geyser of water out of the boat. I inspected the lower port side of the engine forvisable crack[ as I had done when I purchased the engine used] I see no external cracks in the block, I have only minor signs of water in the oil. In other words the oil in new and only a 1/4 inch over the full line on the stick. I had previously ran the engine for 10 minutes last fall after installation. I stop when I heard the engine was hydralocking and stopped and put the boat to up till now.

so does that mean last fall ya lubed the cylinders with oil, after an oil change, then had water shooting out #6, then ya put it up till now? w/o changing the oil? w/o draining the block and manifold over winter?

I know we had some 100 Degree day last september and most of the water should have evaporated.

or maybe rusted things up well if left inside the engine..

My question is do these manifolds suffer from corrosion and deteriation

yes.
here's a pic of my manifold after it went.

i filled up the water jacket with water, the result was full water transfer from the cooling side to the exhaust runner side. ya can see the water trickling down the inside by the choke riser tube. this leak was only on the inside. though the outside of the manifold looked rusty also, but no leak on the outside. it just rusted from the inside and failed.
i never took my plugs out but i did get about a 1/4'' added to my dip stick too. turning cholcolate milk.
for water in the oil. check this out.
my cure was a new manifold and riser. just figured if one was on the way out from '75 the other couldn't be far behind.

 

[michaelbluewolf]

Re: Diagnostic Help with Mercrusier 165 inline 6

I drained the the block at the lower water jacket plug last fall and drained and changed the oil and filter, and sprayed oil into the cylinders before putting the boat away last fall. I found the water in # 6 cylinder this past weekend. And yes, I sprayed oil in the cylinders again before attempting to turn the engine over. I have spent many years as an auto mechanic GM, Honda, Also did a lot of 55,56,57 Chevy restro-mods in my own shop in California for many years. I do have some idea of whats going on when you store a engine for any length of time. Thanks for the many responses. I will remove the manifold this weekend and inspect it. Good news is I have the other manifold and engine that came in the boat when I bought it, [The truck engine] thats complete and the manifold looks good inside.
I figured I should order new Studs for the manifold when I order the gasket kit, That seems like a good idea, and I'll leave that to you guys that are more experienced than I am with this Marine Stuff.
I was worried that I might have a bad head gasket or worse a cracked head or block. I will be relieved to found the manifold is the problem.
Thanks Again to all who respond.

 

[fishrdan]

Re: Diagnostic Help with Mercrusier 165 inline 6

I drained the the block at the lower water jacket plug last fall...

Did you drain the manifold too?

 

[michaelbluewolf]

Re: Diagnostic Help with Mercrusier 165 inline 6

Thanks, Don I will check the risers on both the manifolds for corrosion and or damage to the metal. Unfortunately, my wife has the camera in California visiting[sigh]. Note to self buy another camera.......

 

[michaelbluewolf]

Re: Diagnostic Help with Mercrusier 165 inline 6

I tried to remove the drain plugs but could not, I did remove the exhaust connector hose at the transom and blew it out with air. I removed the original temperture sender below the thermostat housing and installed a seperate AutoMeter Temp gauge with a metal capulary sender to get a better temp reading and when I removed the sender there was only a dribble of water. I am hoping the manifold is the problem, I will have to wait and see whats going on.
Thanks, Mike