New Engine Replacement - Engine Died and Hydro locked after 5 hrs!?

[CaptnO]

According to Volvo Penta site looks like I have 3 bellows total. What is this 3rd one for? Part no: 3587641

Looks like 23075752 = U Joint Bellow Kit
3850426 = Stern Drive Exhaust Bellow (the one that I am missing?)
3587641 =Another Exhaust Bellow?

My TSK: SX-MHP according to my notes from previous owner.

There are different part numbers though from the DP-SM vs SX-MHP?

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[kenny nunez]

The third bellows might be the one where the shift cable enters the hose that guides the cable to the drive.

 

[bruceb58]

Exhaust tube

 

[alldodge]

^^agree exhaust tube
Can either install a bellows which exhaust exits at the drive, or the tube which exits at the transom

 

[Lou C]

Looks like yours came with the exhaust tube instead of the exhaust bellows. And yes there is a small bellows at the top of the shift cable tube inside the boat where the shift cable comes out. This one normally is part of a a new shift cable assembly, but probably be replaced separately if it starts to come apart.
As far as what you should use, tube vs bellows it’s hard to say really. Might have to ask your Volvo tech & see what they say.
The ujoint bellow is the important one and should be inspected every year and replaced as soon as you see small cracks in the folds.

 

[bruceb58]

And yes there is a small bellows at the top of the shift cable tube inside the boat where the shift cable comes out.

Mine had a small grommet but nothing like used to come on the OMC Cobra. Not even sure mine even had one in the end. I also don't see any on any part breakouts.

 

[CaptnO]

Looks like the two that I am supposed to have are in there. The newer one being the U Joint Bellow.

Now looking at my static line measurements I'm still at 10-11 inch. So that is slightly lower then spec however confirmed with Chapparal dealer and the standard size risers are the correct ones from my original setup.

 

[alldodge]

Never heard of cobalt doing something that off of spec, so wonder if the hull is water logged

 

[Lou C]

am I reading this right, from the gunnel to the water line you are 35", from the gunnel to the tops of the elbows you are 22" so 35"-22"=13", looks like you are right at the spec. I'd find a flapper to fit in place of that exhaust tube, measure the outside diameter of the flange, to prevent a recurrance of the water ingestion. Looks like the mechanic did in fact change the driveshaft bellows.
Since you are right at the spec (I am assuming un-loaded) if you are not going to fit taller elbows (which can add some complication) then for sure I'd fit the flapper. If you were at like 15" in terms of static water line that would be different, but being right at the spec not loaded, you need some more protection from back wash than what Volvo has there. And of course they don't know how Chapparal set up the boat, but if it were mine that's what I'd do. Salt water in your cyls is BAD BAD BAD. I had this with 2 blown head gaskets and was able to save the old short block by fogging and draining it till I could take it all apart. And, that worked because there was no rust inside at all when I took it apart.

 

[CaptnO]

am I reading this right, from the gunnel to the water line you are 35", from the gunnel to the tops of the elbows you are 22" so 35"-22"=13", looks like you are right at the spec. I'd find a flapper to fit in place of that exhaust tube, measure the outside diameter of the flange, to prevent a recurrance of the water ingestion. Looks like the mechanic did in fact change the driveshaft bellows.
Since you are right at the spec (I am assuming un-loaded) if you are not going to fit taller elbows (which can add some complication) then for sure I'd fit the flapper. If you were at like 15" in terms of static water line that would be different, but being right at the spec not loaded, you need some more protection from back wash than what Volvo has there. And of course they don't know how Chapparal set up the boat, but if it were mine that's what I'd do. Salt water in your cyls is BAD BAD BAD. I had this with 2 blown head gaskets and was able to save the old short block by fogging and draining it till I could take it all apart. And, that worked because there was no rust inside at all when I took it apart.

So the water line actually comes up to about 33.5-34 inches. Then from the riser it's about 21.5 so that is 12-11.5. both of my drains are covered up when I am in the water

 

[Lou C]

OK well I think that's too low. Mine were like 14-15". Think about getting the taller elbows, every boat sits a bit different in the water, and you don't want a recurrance of salt water in the cyls. If you don't want to get involved in fitting taller elbows, then get the flapper at least.

Keep in mind that elbows that are too low relative to the static water line can let water in more than one way. In addition to the issue with water rushing up the exhaust if you slow down too fast, reversion (a suction effect that is caused by pulses of the intake/exhaust strokes) can pull water up the 90* exhaust pipes at low speeds when there is not enough exhaust pressure to blow it out. This is more pronounced in the Vortec series of engines that came out around '96 because of different cam timing. On the V6s it was worse than on the V8s apparently because they re-designed the 90* down pipes to make the angle sharper and added one way check valves in the elbows to prevent vacuum from sucking water up the exhaust at low speeds. So if the elbows are too low, then water getting in from reversion is somewhat more likely.

The other issue with Volvo style exhaust is that the manifolds run very cool at idle, like 95-110*. Running slow just above idle you can actually get condensation in the exhaust that can run down and cause slight misfiring if it gets beyond a certain level. Mercruiser used a warm manifolds set up to eliminate this issue (on theirs, they didn't feed water to the manifolds till the thermostat opened up at approx 160* so the manifolds stay above 120* which is the temp below which condensation is likely). So they had the manifolds fed by the stat housing when the stat opened but the elbows got cool water all the time. Volvos's system (basically a copy of OMC's) is simpler, just one feed hose for the manifold and elbow. If your engine runs at about 160* it probably won't be a problem but if your stat gets sticky (common in salt water) and the engine runs too cold it can become an issue in no wake zones....

I found this out by accident because this year I tried a 140* stat because for years I heard, that you should use a 140 stat in salt water. Well OK I tried it and then one day I had to finally fix my leaky steering actuator. I had to pull both manifolds off to get at it. The engine was run earlier that day. To my surprise I found clear evidence of condensation in the exhaust, the engine was running about 25* cooler with the 140 stat. So as part of this job I put the 160 back in.

 

[CaptnO]

Never heard of cobalt doing something that off of spec, so wonder if the hull is water logged

How can I know if this is the case?

 

[Lou C]

only thing you can do is weigh the boat and compare to their specs.
Its not that unusual for boat companies to get the static water line issue wrong and it got worse with the Vortec series of engines. Everyone liked the extra power but static water line became even more critical.

 

[alldodge]

With the upper one being under water the boat has to have taken on water. Take it to a CAT truck scale and weight it. If you haven't done it before, go inside first and tell them what you want to do. Pull the boat in and disconnect it from the truck, making sure the boat sits completely on one of the sections.

Spec shows 5200 dry boat only

 

[CaptnO]

Oh man... I hope not. So if my boat is sitting lower then that could be the reason why the static line is out of spec. I guess I should weigh first before spending money on higher riser. Also if going with a higher riser option can I just purchase the extension? Do I need to get the higher riser 11.3"? Or do I need to buy a whole kit? Volvo Parts store doesn't really explain it to well.

I am going to go for another water test tomorrow, I am going to double check to see how low the boat is sitting in the water. I will look at it from the boat ramp this time instead of in the windy conditions and middle of the river I was in yesterday.

 

[CaptnO]

OK well I think that's too low. Mine were like 14-15". Think about getting the taller elbows, every boat sits a bit different in the water, and you don't want a recurrance of salt water in the cyls. If you don't want to get involved in fitting taller elbows, then get the flapper at least.

Keep in mind that elbows that are too low relative to the static water line can let water in more than one way. In addition to the issue with water rushing up the exhaust if you slow down too fast, reversion (a suction effect that is caused by pulses of the intake/exhaust strokes) can pull water up the 90* exhaust pipes at low speeds when there is not enough exhaust pressure to blow it out. This is more pronounced in the Vortec series of engines that came out around '96 because of different cam timing. On the V6s it was worse than on the V8s apparently because they re-designed the 90* down pipes to make the angle sharper and added one way check valves in the elbows to prevent vacuum from sucking water up the exhaust at low speeds. So if the elbows are too low, then water getting in from reversion is somewhat more likely.

The other issue with Volvo style exhaust is that the manifolds run very cool at idle, like 95-110*. Running slow just above idle you can actually get condensation in the exhaust that can run down and cause slight misfiring if it gets beyond a certain level. Mercruiser used a warm manifolds set up to eliminate this issue (on theirs, they didn't feed water to the manifolds till the thermostat opened up at approx 160* so the manifolds stay above 120* which is the temp below which condensation is likely). So they had the manifolds fed by the stat housing when the stat opened but the elbows got cool water all the time. Volvos's system (basically a copy of OMC's) is simpler, just one feed hose for the manifold and elbow. If your engine runs at about 160* it probably won't be a problem but if your stat gets sticky (common in salt water) and the engine runs too cold it can become an issue in no wake zones....

I found this out by accident because this year I tried a 140* stat because for years I heard, that you should use a 140 stat in salt water. Well OK I tried it and then one day I had to finally fix my leaky steering actuator. I had to pull both manifolds off to get at it. The engine was run earlier that day. To my surprise I found clear evidence of condensation in the exhaust, the engine was running about 25* cooler with the 140 stat. So as part of this job I put the 160 back in.

Nice info. So wonder if my boat is setting lower now because the hull could be water logged, which would explain why my water static line isn't to spec. Got some more testing to do. My Volvo tech thinks I am being paranoid about the risers as he already confirmed that the ones installed are the correct ones for my boat. However when I told him that both of those drains on my boat were below the waterline he aso threw that idea of perhaps my hull being water logged. Again I'll double check everything tomorrow. I probably won't be able to weigh my boat until this weekend though, those CAT scales are like an hour away, I thought maybe I can fine a truck scale on the hwy or some masonry place close by that might have a scale I can use.

Also I am freshwater on the Potomac river so I suppose that is not as bad as salt water getting into my engine. My engine temps read a solid 160 according to my gauges. I'll be curious to see what my riser temps are as they don't usually get that hot but then again it's like 40 degrees outside so that is some cool water running through the engine at this time.

 

[bruceb58]

Never heard of cobalt doing something that off of spec, so wonder if the hull is water logged

Please don't call a Chaparral a Cobalt! LOL

 

[CaptnO]

God damn engine felt like it was stalling out so I shut down and tried to restart but it was too late. Water injesction again. I removed the spark plugs and water came out in s few Cylinder 8 had the most water that came out. This is definitely happening when coming to a slow down i was 3100rpms. Then slowed it to about 2 grand the dropped it to 1500 and it died again after about 30 seconds this time. I believe I am able to duplicate the problem and it had to do with slowing down or once I come off plane and transition to no wake. It seems like the danger zone is from 2000rpms-1400 rpms. Slowing down from abobe 3k.

I also notice that my boat won't hold plan once I dip below 3k rpms is that normal?

 

[CaptnO]

Here at esome videos, we didn't get the two times it stalled but maybe this might give some people an idea of what's happening back there when slowing down.

New video by Orlando C Karpf (OCKarpf)

photos.app.goo.gl

New video by Orlando C Karpf (OCKarpf)

photos.app.goo.gl

 

[CaptnO]

Here are all the videos and photos from today.

I rechecked were the water line was this time once I put the boat in the water today at the ramp and those drain holes were above the water this time. So maybe it was just the windy conditions on Monday which made it seem that they were slightly higher. I'll keep monitoring this.

Photos and videos here