water in new engine from ?????

[trooperjim]

I have a 4.3 in a stingray that I bought knowing that the block was cracked from winterizing issues. I replaced the block with a used one. The engine has totally been rebuilt twice and has just messed up a 3rd time each time during the runup after installation. It keeps getting water in it. It is showing up in the oil filter and where the alarm horn plugs in because I have a manual oil pressure gauge plugged in there temporarily. However, It's not showing up on the dip stick yet. The machine shop is about to pull their hair out as well as me. Thank goodness the work is under warranty. The intake pressure tests ok. Is it possible for the exhaust manifolds to be contributing to this or is going to be hidden somewhere in the donor block or heads?

 

[Alpheus]

Re: water in new engine from ?????

Are your exhaust manifolds/risers new?

If not I betcha that is your problem.

Its not a good practice to put used manifolds and risers on a new engine, especially ones that were installed on an ice cracked block...

Start by having your manifolds pressure tested...

 

[TilliamWe]

Re: water in new engine from ?????

No, there is no connecting between the manifolds and the engine oil passages...

Really? I'll bet you a nickel that there is. (You can owe me the nickel right now, cause i am right.)

While internally failed exhaust manifolds shouldn't be able to cause much water to get into the oil, it's still possible. When the manifold(s) fail, cooling water enters the exhaust ports, runs in through the open exhaust valves, and fills up the cylinders. If the rings are worn (yours shouldn't be, but hey, maybe your used block's cylinders aren't round anymore?) the water will pass by the rings and directly into the oil pan (Bubba, that's the explanation as to why you owe me a nickel! )
Re-using exhaust manifolds on an engine that wasn't winterized properly and cracked the BLOCK, just seems like a bad idea to me. Wouldn't it stand to reason if the ENGINE BLOCK cracked, that the exhaust manifolds could do the same? After all, they are all cast iron, and the engine block is probably thicker walled than the exhaust manifolds.

Good luck.

 

[45Auto]

Re: water in new engine from ?????

Check for a cracked cylinder head if you're re-using the old heads.

 

[zbnutcase]

Re: water in new engine from ?????

Really? I'll bet you a nickel that there is. (You can owe me the nickel right now, cause i am right.)

While internally failed exhaust manifolds shouldn't be able to cause much water to get into the oil, it's still possible. When the manifold(s) fail, cooling water enters the exhaust ports, runs in through the open exhaust valves, and fills up the cylinders. If the rings are worn (yours shouldn't be, but hey, maybe your used block's cylinders aren't round anymore?) the water will pass by the rings and directly into the oil pan (Bubba, that's the explanation as to why you owe me a nickel! )
Re-using exhaust manifolds on an engine that wasn't winterized properly and cracked the BLOCK, just seems like a bad idea to me. Wouldn't it stand to reason if the ENGINE BLOCK cracked, that the exhaust manifolds could do the same? After all, they are all cast iron, and the engine block is probably thicker walled than the exhaust manifolds.

Good luck.

Wrong! The manifolds are much,much, thicker than todays paper thin GM blocks!

 

[fossill]

Re: water in new engine from ?????

True, but you still cant assume that they are ok after freeze damage to the engine.

 

[jy118lfd]

Re: water in new engine from ?????

Many an engine has had a water intrusion problem due to bad risers and or manifolds. If you have not replaced them then now would be the time. Water in oil first place to look is the condition of the riser to manifold joint. pop off a riser and take a pic of the manifold and riser after cleaning off all the gasket material. We can then tell you if they are bad.

 

[trooperjim]

Re: water in new engine from ?????

for what it's worth, i hooked a water hose onto the manifold and water only came out where it is supposed to. I realize i need pressure and heat but, that's the best I can do. I talked to one of the service guys at one of the larger marine shops locally. He advised that there was no way to pressure test the manifolds that he knew of and also wanted to know why i would even want to do it? i told him and he said it was going to be an intake,block, head problem. The donor block was completely machined and bored 30 over so I don't think that is the problem. Where is a good place to get new manifolds? could this be somewhere in the block walls? that's what all my mechanic friends are thinking, but, they don't do much with boats.

 

[trooperjim]

Re: water in new engine from ?????

Not a chance of leaking? or not a chance of working?

 

[Silvertip]

Re: water in new engine from ?????

Has the current block been magnafluxed? If water is getting into the filter it can also get into the pan and pushed through the filter which is the route it is likely taking. Has the current engine been treated to an aftermarket performance camshaft which lends itself to reversion issues. I also feel since the block was cracked, so also can the manifolds/risers.

 

[trooperjim]

Re: water in new engine from ?????

i'm not sure about the magnaflux I kind of doubt it. does anyone know where to buy new manifolds?

 

[trooperjim]

Re: water in new engine from ?????

One other thing i noticed when we were running it up was that the water exhaust on the starbard side was 30 degrees warmer than the port side. Starbord was 140 degrees and port side was 110 degrees. I read in some other posts that this was normal.

 

[fossill]

Re: water in new engine from ?????

Intake manifold gasket leak is another possible leak area.. I assume the intake and its surfaces are in plane.

 

[TilliamWe]

Re: water in new engine from ?????

Wrong! The manifolds are much,much, thicker than todays paper thin GM blocks!

Okay, but fossill's right, you can't assume they are good after freeze damage to an engine.

 

[TilliamWe]

Re: water in new engine from ?????

Not a chance of leaking? or not a chance of working?

Not a chance that Bubba is going to admit he's wrong. I typed it in plain english how water from the exhaust manifolds can get into the oil of ANY (fresh water has NO bearing as to where water will end up!) Chevy marine engine. Yet he dismissed it with one sentence? He's not correct, and he knows it.

These 4.3 are somewhat known for intake issues. I know the Op says his was tested, but it wouldn't surprise me if it's the culprit, if the exhaust system isn't the issue.

 

[Lyle29464]

Re: water in new engine from ?????

I have seen water in the oil many times caused by a bad riser. some did not freeze. They just burned through from the inside and rusted through from the water jacket.

 

[trooperjim]

Re: water in new engine from ?????

My problem ended up being a crack in the block. Thanks for the suggestions from everyone.