overheated, water in cylinders

[kzabrisk]

I have a 2002 Four Winns - 5.7 Volvo Penta GXi
Story -
Forgot to reconnect the hoses to the impeller housing and took it out for the first time this year. The engine quickly overheated and was restricted to low RPM usage. Shut off engine and paddled in.

What I've done so far -
I checked/replaced the impeller - it was toast and most of the fins were gone - only 3 or 4 were still attached, some were inside the housing where the impeller resides, there was one down in the bilge. I haven't found them all, still missing about 5 but I don't think any would be located inside the cooling system since the hoses weren't even attached.

The engine starts fine and runs ok with muffs. I ran it for awhile at idle and then for a few minutes at 2800 RPM and temp seems to be holding fine. The oil looks clean, clear with normal colorization, no water/bubbles etc. I am concerned that there might be additional engine damage, so I pulled the plugs and did a compression check on each cylinder. While doing this, I noticed water in all of the starboard side cylinders. Also, the compression averages higher on the starboard side which I find interesting. Starboard front to back compression is - 155, 160, 160, 145 ; Port side front to back is 135, 120, 135, 130.

I have the overheat diag pdf from Volvo that seems to be referenced in this forum quite often and I'm reading thru that at the moment. So - my questions...

The obvious question - the source of the water leak to the cylinders
Since the compression seems ok, except for the strange average difference port to starboard, does that mean that the head gaskets are probably ok?

I very much appreciate any help given.

 

[Maclin]

Re: overheated, water in cylinders

The water in all cylinders on just the one side sounds like a problem with the exhaust manifold, like maybe it cracked over the winter between water passage and the exhaust passage and water can get into the exhaust side and enter any cylinder that has an exhaust valve open when the engine is stopped.

 

[Senior B]

Re: overheated, water in cylinders

With compression numbers like that I would say your head gaskets are ok. For the year of the boat, if the exhaust manifolds and risers are stock, I would say that your stbd riser gasket is very suspect for the water on the right side. At the very least I would remove both risers and inspect the gasket surfaces. This is very easy to do and will tell you the condition of both riser and manifold. Use the Volvo OEM gaskets if you put the risers back on or replace them. Good luck.

 

[kzabrisk]

Re: overheated, water in cylinders

The water in all cylinders on just the one side sounds like a problem with the exhaust manifold, like maybe it cracked over the winter between water passage and the exhaust passage and water can get into the exhaust side and enter any cylinder that has an exhaust valve open when the engine is stopped.

I'm unfamiliar with how the water flows for cooling. So there are water 'jackets' in and around the exhast manifold and riser?

 

[Maclin]

Re: overheated, water in cylinders

Yes, the exhaust manifolds are very specific Marine units with two passages. The spent raw water used for cooling is sent thru the manifold water passage then out the top into the riser where it meets the exhaust gases, then flows on out the exhaust. The water in the exhaust is also necessary to keep the big rubber hoses cool and not melt when the engine is running. Also keeps temps down in the tight engine bay.

Since you said this all happened on the first time it was run this season, I was thinking that the manifold may not have been drained properly and a hard freeze expanded residual water and cracked the manifold internally. Then when you ran it first time this season the water could find a way into the exhaust passage once the engine stopped, then would just flow past any open exhaust valve(s) into that cylinder.

Where do you live?

 

[Maclin]

Re: overheated, water in cylinders

The exhaust(ed) water can also cross over into the exhaust at the riser junction gasket, as Senior B mentioned. My cracked manifold scenario is only one of the possibilities for how the water got in.

 

[kzabrisk]

Re: overheated, water in cylinders

I live in Utah and so, yes - there is a couple of weeks where a good hard freeze occurs in early January. I guess it's a possibility that I didn't winterize appropriately and the manifold has a crack in it. I really don't think so, but it's possible. I do remember draining them both.

Pulled the exhaust manifold and riser off and separated the two components. Now I understand how the water flows - looking at it and your comments helped. The gasket between the manifold and the riser appears to be compromised. There is rust on both sides of the gasket between the exhaust and water jacket. Since it seems like a relatively easy fix, the compression seems good in all cylinders and the oil is clean, the plan is to clean it up, attach with a new gasket, put it back together and run the same test and see what happens. It makes me wonder if the overheating messed up the gasket, or if it's been that way for awhile.

Then again - I suppose it wouldn't be too much trouble to also do that acetone test to check for cracks in the manifold that I read about. Does that really work?

 

[Senior B]

Re: overheated, water in cylinders

So you have removed the Risers and see signs of water pass through..Now, look carefully at the inner Gasket Seating Surfaces on both the Riser and Manifold. The Riser surface is usually the first to go and for the age of your boat it's time to replace them if they're stock. My boat is the same year as yours (2002 I believe) and I had to do mine this year. My Riser Gasket Surfaces were easily 70% gone and I had water seepage on the left side. Manifolds looked almost new but I still replaced both. If you suspect freeze damage then just replace them. You said you did drain them but if they're pluged up with rust, they might not have drained all the way and Utah gets plenty cold enough I suspect in the winter.

 

[kzabrisk]

Re: overheated, water in cylinders

hmmmm... the surface area where the gasket goes looks pretty good and flat after I followed the directions that come with the OEM gaskets to remove the old gasket material. There's a few places where the coloring is not shiny new metal, but I can't see any pitting. I don't know... I feel it would be crazy to replace them at this point. I did the acetone test and it passed, so I'm going to reuse them. I'll take a picture and post.

 

[kzabrisk]

Re: overheated, water in cylinders

forgot the picture -

so it's all done and buttoned up. I did the other side and the gasket looked about the same, so it was probably just a matter of a few more hours before water would start leaking on that side also. Ran it with the muffs and it seems fine. Planning on taking it out on the lake tomorrow to test.

Can anyone tell me where I can get bolt torque info?

 

[kzabrisk]

Re: overheated, water in cylinders

Water test went well. I ran it at different RPM's for 30 minutes and it runs the same as I remember. I think this thing is fixed. But, of course, won't really know until it get's some good usage.

A few other points...

A post compression check on the starboard side renders normal numbers - 150 or so. I'm told that the reason it was higher before is because the water in the cylinders would have reduced the size of the chamber and since water does not compress, the result is a higher reading. Once the water is gone the compression returns to normal. Several checks of the plugs after use showed no indication of water. So, I'm sure now that the water was entering the cylinders from the failed gasket between the exhaust manifold and the riser as stated by Senior B.

The crankcase oil - when looked at on the dipstick - seemed fine - golden color. As a precaution, I replaced the oil and filter. When looking at the used oil in a container, it looked a little muddy at first and then just dark brown. I am still concerned about this since everyone says that if it looks like chocolate milk, then you've got a cracked block. I'm just hoping that the reason my oil looked that way is because some water worked it's way passed the rings. The only way to tell for sure is to do a block pressure check. Or... I can just use it and keep a close eye on the oil level and colorization. I'm not even convinced at this point that the overheating situation caused the manifold/riser gasket to fail. I'm thinking that since they were already 10 years old, that the overheating just pushed it over the edge. It may have been already leaking a small amount before and I wouldn't have noticed it.

There are two heat sensors on top of either riser that apparently just kinda fell apart when it overheated. The main part is still screwed into the riser, but the tip of it which is connected to a wire just fell off when working on the risers. I'd love to replace them, but no boat shop near me has them in stock and I called 7 of them. Had to order them. Seems strange to me that no one would stock these. Am I the only one that overheats and engine around here? I would think it's somewhat common.

I hope this thread helps someone. I've sure learned a lot from others threads and comments. Thank-you.

 

[Mbaska1505]

Re: overheated, water in cylinders

Water test went well. I ran it at different RPM's for 30 minutes and it runs the same as I remember. I think this thing is fixed. But, of course, won't really know until it get's some good usage.

A few other points...

A post compression check on the starboard side renders normal numbers - 150 or so. I'm told that the reason it was higher before is because the water in the cylinders would have reduced the size of the chamber and since water does not compress, the result is a higher reading. Once the water is gone the compression returns to normal. Several checks of the plugs after use showed no indication of water. So, I'm sure now that the water was entering the cylinders from the failed gasket between the exhaust manifold and the riser as stated by Senior B.

The crankcase oil - when looked at on the dipstick - seemed fine - golden color. As a precaution, I replaced the oil and filter. When looking at the used oil in a container, it looked a little muddy at first and then just dark brown. I am still concerned about this since everyone says that if it looks like chocolate milk, then you've got a cracked block. I'm just hoping that the reason my oil looked that way is because some water worked it's way passed the rings. The only way to tell for sure is to do a block pressure check. Or... I can just use it and keep a close eye on the oil level and colorization. I'm not even convinced at this point that the overheating situation caused the manifold/riser gasket to fail. I'm thinking that since they were already 10 years old, that the overheating just pushed it over the edge. It may have been already leaking a small amount before and I wouldn't have noticed it.

There are two heat sensors on top of either riser that apparently just kinda fell apart when it overheated. The main part is still screwed into the riser, but the tip of it which is connected to a wire just fell off when working on the risers. I'd love to replace them, but no boat shop near me has them in stock and I called 7 of them. Had to order them. Seems strange to me that no one would stock these. Am I the only one that overheats and engine around here? I would think it's somewhat common.

I hope this thread helps someone. I've sure learned a lot from others threads and comments. Thank-you.

Was the problem just the gaskets. I’m having the same issue