water ingesting into motor?

[302mustang]

How does this happen?

96 volvo penta, glastron, 4 cyl I/O

1. head gasket fine
2. Rust found in 2 adjacent cylinders (#3 and #4)
3. Water and oil mix
4. Block is not cracked
5. head is not cracked and does not appear to look bad
6. rust also found in ports of head
7. Previosly broke belt and overheated motor

Can my exhaust possible be sucking in water? Why do I have rust. I know I had low compression on the #3 cylinder.

Before teardown, I changed the oil and ran it for about 20 minutes and oil was milky but not as bad as it was before I pulled it out. It is retaining it's oil color.

the exchaust boot was loose and leaking exhaust on one trip. I have since then tightened the clamp.

I'm wondering If I had corrected the problem with it ingesting water by doing this.

I can't understand why this might be happening.

 

[Haut Medoc]

Re: water ingesting into motor?

Bad exhaust manifold or riser/manifold joint leaking water into the cylinders throug open valve.......
When you are at rest water seeps past the cylinder with low compression.....
How low is that cylinder?.....
& how quickly do you see the water in oil?
Tightening that clamp is not gonna help....​

 

[302mustang]

Re: water ingesting into motor?

The others tested at 150
the number 3 cylinder tested at 90 and it took a few revelutions to get it that high.

I need more information on how i'm ingesting water through exhaust. I don't understand how to fix this.

 

[hullofalottatrouble]

Re: water ingesting into motor?

with that compression number i think you have a bigger problem than just solving why the water is getting in there.. thou the two maybe related.. your next step might be a leak down test on that clyinder to determine where it is losing compression then take it from there..

if you have rusted out or cracked exhaust manifolds or bad gasket or bad mating surfaces or missing flappers and dieseling or slowing down to quickly etc etc.. the water in the exhaust will get into the air passages in the exhaust and leak into the cylinders.. happened to me when i didnt torque the elbow down enough after swapping out the gasket..

 

[302mustang]

Re: water ingesting into motor?

motor is tore down. Can't do a leak down. However the number 3 and 4 cylinders have rust in the head and around the valves, telling me they can't be working very well. I'm going to have the head sent out or depending on the costs possibly buy a new head.

At this rate should i scrap the motor all together? Is it worth fixing? where do I go for help after I get the head back?

Should I pay somebody to look into it for me? Or should I just put the boat back together and sell it?

 

[302mustang]

Re: water ingesting into motor?

Also, the boat didn't diesel. I would start fine cold. Run great, and when I would put a load on the motor and come to a fishing spot, it would be hard for me to restart it. I would have to peg the throttle to get it going again.

I could start and stop it all day long in my driveway out of the water.

Hope this helps you to help me.

 

[302mustang]

Re: water ingesting into motor?

I took a few pics of the motor... Lots of rust. This coming from a boat that started fine 2 weeks ago and has the symptoms i am describing. I felt along the cylinder walls and don't notice and grooves.

Where i have the red arrow indicates my exhaust. Is this where my problem lies? Do i need to snap a few of the head?

Thanks for the help guys.

 

[Bt Doctur]

Re: water ingesting into motor?

most likely a hole in the riser dropping water into #3 and #4. if it`s rusty on the exaust port it`s the riser, if it`s rusty on the intake it`s a cracked manifold

 

[302mustang]

Re: water ingesting into motor?

Okay so what exactly is the riser and is it cheap? How hard is it to fix? And can this motor be salvaged with some cash and TLC?


Thanks.

P.S. Is there anyway to test the riser to prove it's bad? And what causes this? Thanks.

 

[cincinnati sundancer]

Re: water ingesting into motor?

you need to let your motor idle for 5 minutes before turning it off. this gives the heat exchangers time to depressurize. problem solved.

 

[Bt Doctur]

Re: water ingesting into motor?

check your pm