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Water in oil

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Hello all, new to this.......
HELP! A long story short. I had my port 454 Gen IV engine rebuilt, long block. I was getting sea water in my oil from a sticking valve and was told by the rebuilders that my exhaust was causing the problem. I put new exhaust manifolds on after the rebuild (the other exhaust parts are approx. 2 years old) and while working out the bugs after putting her back together I fould my coolant level going down and water in the oil. I have drained the oil and thinking I might have a stuck valve, did a compression check and fould all cylinders at 150.
Where could this be coming from? Could a riser do this? :confused:

Another issue is that I can't seem to get the rpm's up on the engine (before I started getting water in the oil). I'm good to about 24 - 2600 and then nothing more. The plugs were pretty black when I pulled them which made me think maybe my carb (quadrajet) air/fuel mixture wasn't right or something else?

Any input would be greatly appreciatted.....

JP
 
It would be more likely that an exhaust elbow or riser would introduce raw water long before an exhaust manifold. You need to stop the water intrusion, then the coolant leak, then get it running right. Guessing as it isn't clear from your posts, that these issues are still present.

If the cast iron is ok, the only other issue with the exhaust would be the joints. Guessing either a gasket was messed up, missed, or the fasteners were never re-torqued after the initial warmup.

On the coolant loss, get a radiator pressure tester. Most 'big box' auto parts stores will loan/rent them to you. That vintage should be ok without any adapter. Don't forget to check the cap, too. You may be lucky and find a loose hose clamp on this one.

As far as the low rpm, with black plugs, minor flooding is possible. (You did have the carb rebuilt while the engine was done, didn't you?) known candidates are dirty needle & seat or a soaked float (many kits don't include the float). Make sure the iginition system is in good order and adjusted properly as they will restrict rpm, too.
 
Sea water in oil?, the only access water has to your oil system is thru a intake gasket failing, an oil cooler with in holes from corrosion, or head bolts that weren't sealed properly and its allowing coolant to seep into the engine.

Are we sure its not coolant mixing with the oil, Its possible that the intake is leaking and vacuum is sucking coolant thru the system, might explain the poor performance, but then you will have steam in exhaust, and a sweet smell from the antifreeze in the exhaust.

An exhaust valve sticking doesn't have coolant near it, unless the head is cracked. Compression at 150 is good, means rings, and valves are seated.

Running with water in the oil, will destroy the bearing pretty quick, try this, reroute the oil cooler (if you have one), its safe to run a short time with the the oil cooler disconnected. change the oil (use cheap as your are going to change again), mark the dipstick, don't rely on the full mark. run the motor and see if the oil level increases, if it doesn't bad cooler, if it does, then you got an internal issue with the motor.

Was the motor rebuilt for this issue and you got the same problem, or was this after the rebuild?

let us know
 
OK, COOLANT in the oil. Do what MM suggests and pressurize the HE. If you want, block off both exhaust manifolds, using hose plugs. If it leaks, and it likely will, that means the intake man is coming off. It might be possible to see at that point if the int. manifold caused the leak, maybe at one of the gasket surfaces. If it is a head issue, that might be difficult to diagnose on the engine. Seems to me, exhaust valve area cracks, and riser gasket issues will dump coolant out the exhaust and not impact the oil.

Since you had seawater issue before and now a coolant issue, they may not at all be related. A wild guess is that intake manifold gasket was not well sealed witih RTV during assembly.
 
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I've seen a few engines reassembled without sealant on the headbolts. Going on memory, every one of them leaked coolant into the pan.
 
Thanks all for the input………
After going back to the boat to change oil for a second time, I'm embarrassed to say that I found "ALL” of the intake bolts to be loose…….
All else appeared to look o.k.…….
Guess that too would attribute to poor running? Also, I did not rebuild the carb thinking that having it done about 2 years ago it would still be fine.
Any recommendations on timing? I set it at 10 degrees as a starting point but have not adjusted under load?
 
10 deg BTDC is a good starting point....just make sure the advance is working smoothly. I'd also get a vacuum gauge on it to make sure the intake sealed completely. Once broke in and fully seated, the engine you provide around 18" Hg at a fast idle.
 
How would you check to make sure the advance is working smoothly?

Also MM, didn't understand your last, "Once broke in and fully seated, the engine you provide around 18" Hg at a fast idle".
 
Timing advance is checked with a timing light. An "electronic advance" type is easiest to use. If not available, a regular one will work. A timing tape makes this way work easiest. If not available, you can always mark the balancer.

Once the rings have seated, a big block with a marine cam should be able to generate ~ 18" of vacuum, in the intake manifold (use a vacuum gauge), when at fast idle. This indicates the top end is in reasonable shape.
 
I torqued down my intake bolts , changed the oil again and started the engine. What I see now is after it wormed up, I have steam from the exhaust. Should I check/change the intake gaskets or is that moisture that is still in there burning off?

Just wondering what to do.....
 
Steam during or just after a cruise power setting? Or, steam just sitting at idle? Either the coolant level is dropping or, I think your raw water flow is low. Have you looked at the inside of the raw water pump lately? How old is the U cooler?
Are there tuna or wahoo off of your wall now?
 
The steam started after warming up while just at idle for a few minutes, not taking the boat out and running it. I was watching the coolant level too and it didn’t seem to drop. I haven’t checked the raw water pump.
Which cooler are you refering to? Just coincidental that it started after retorqing the intake back down.
Tuna are starting to show up again………
 
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