Water in starboard cylinders only. No water in oil. 5.7 Mercruiser (UPDATE-FIXED)

[Ridewright79]

Hello I am new to the forum but have been using it for info. I have to say i find the most accurate info here. I have a 95 stingray that i bought used.It has a crank mounted seawater pump and the pickup is on the bottom of the hull. The last three times I took it out I have encountered a hydro lock issue. The first time i ran it for 12 miles, then shut down for three hours, ran for another 30 minutes before going in for the night and loaded it on the trailer. the next time i went to start it, it spun half a turn then bang. noticed the starter housing cracked and bolts were bent. Replaced with new oem bolts and high torque starter. started fine. Second time i ran for about 15 minutes and stopped at a beach area on the creek. When i went to start it 5 hours later wouldnt turn over. Called Seatow and towed to the ramp. Pulled the plugs and found water on the starboard side(bank 2)only. pulled the risers and inspected them for pitting and straight edge. all looked ok. I used a straight edge and machined the surfaces flat just to be on the safe side. Suspecting the gaskets may have failed. Installed risers/manifolds with the proper OEM mercruiser gaskets and replaced sparkplugs. This past weekend took it out for a ride. Did great for 15 minutes and stared hearing a slight detonation noise(spark knock) on the starboard bank followed by the motor loosing power and back firing through the carb. Once again Seatow. Pulled the plugs and spun the water out of the cylinders. The number 6 cylinder plug has no electrode left due to the detoination/ water being burned. I can only narrow it down to a head gasket allowing water into the cylinders. it will not act up running on the trailer or without a load.

 

[Don S]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Never mind, didn't read enough.

View attachment 01-13 Gas Engines and Water Intrusion.pdf

 

[Bondo]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Ayuh,... Welcome Aboard,... Sounds like it's time for a Compression Test...

The Detonation could be a separate issue, not connected to the water in the cylinders...
More likely water in the Fuel...

Was there rust tracks on the carbon in the exhaust passages of the manifolds, 'n risers,..??
That's usually a hint as to Where the water came from,...

Where ya at,..?? any chance the motor has ever seen Freezin' temps,..??

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

No I'm in fresh water. I noticed it only happens while on plane or getting on plain. I plan on tearing it down this weekend.....again.....:grumpy:

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Thanks Band-o. when i pulled the manifolds/risers last time the only rust stains/ markings were where the water sat at the bottom of the manifolds. I plan to do a compression check before teardown.

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

I live in Florida and the problem started in august....

 

[achris]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Many manifolds get a corrosion pin hole in places difficult to see. You need to remove the manifold and either pressure test it or fill it with acetone and check for leaks. Same with the elbow...

Chris....

 

[Bondo]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Thanks Band-o. when i pulled the manifolds/risers last time the only rust stains/ markings were where the water sat at the bottom of the manifolds. I plan to do a compression check before teardown.

Ayuh,.... You should also pressure test the blocks coolin' passage, before ya tear it down...

If there's any Cracks, you'll hear 'em....

'n on the Detonation thing,... Inspect the contents of the fuel filter for water, 'n crud...

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

I smoke tested them when i had them off. I know that sounds weird, I'm a Automotive master tech and am finding alot of different logic in some marine designs. Overall I couldnt see any evidence pointing back to the risers/manifolds. Good suggestion on the acetone. I use to do that to check valves in cylinder heads.

 

[achris]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

I smoke tested them when i had them off. I know that sounds weird, I'm a Automotive master tech and am finding alot of different logic in some marine designs. Overall I couldnt see any evidence pointing back to the risers/manifolds. Good suggestion on the acetone. I use to do that to check valves in cylinder heads.

I usually 'float test' a lot of components.... :lol:

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Thanks guys. I inspected the fuel inlet and most of that is new. Still think its odd that only one cylinder burned the plug and the number 8 didnt seem to have any liquid in it. Not sure what all this guy did before me but been correcting things since I bought it. From what the previous owner told me the motor was swapped and is a 93yr model. Also he informed me that the risers/manifolds were the originals????? not sure about that.

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

I usually 'float test' a lot of components.... :lol:

LOL I may start doing that real soon...

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

I guess it would be wise to pressure test the cooling system before opening it up. since its a seawater system, not closed loop, guess i have to find a way to add pressure to the system and block the system off...

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Thanks guys for the info. I will do some digging and post any and all results i can come up with.

 

[achris]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Pull the elbows off the manifolds and put covers on the surfaces, then just pressurize with the incoming water line... Tests the entire system, including manifolds, all at once. If that holds, the problem is elsewhere :der:.... If you have a leak, then remove the hoses from the manifold and recheck.... ect, ect...

Chris...........

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Makes sense. What about the risers?? They are aslo fed from the t-stat housing.

 

[achris]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Makes sense. What about the risers?? They are aslo fed from the t-stat housing.

If you post up the engine serial number we can all know what you're working on. Just saying 5.7 is about like saying you have a Ford car your working on.... It just means it's a 350 V8, been around since Adam was a boy, and in so many variations.

Once we have the engine serial number we can all look up the exact engine and see what runs to where.... and offer more bespoked advice.

Chris......

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Ok I will see if I can narrow the source down. Just frustraighting. Post my findings.

 

[Ridewright79]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

I completely understand what you mean..D832433 is the serial number from the tag on the starboard side.

 

[Bondo]

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Re: Water in starboard cylinders only. No water in oil. 5.7 Mercruiser

Makes sense. What about the risers?? They are aslo fed from the t-stat housing.

Ayuh,... If there's Any doubt, toss 'em,...

By the nature of their design, pressure testin' ain't an option...

Here's some informative readin' for ya,... The Adults Only section,...