BigTime Breakdown 5.7 SBC Water in Cylinders

J

j-d

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As signature, 1996 5.7 with TBI fuel system. This is a Pre-Vortec, flat tappet engine, 1440 hours. Yesterday, lost power, missing, never stalled. Till we approached home dock then it roughened up and quit. Thought it was ignition parts, installed plug wires, cap, rotor, decided to inspect sparkplugs. All four left/portside bank have water. Boat's in the water and I can't get onto the lift till tide rises. When I tried to crank it to blow the water out, just produces more. I think that's because the lower unit/raw water pump (Alpha) are still in the water.
Complete Sierra (former OSCO) exhaust less than a year old. Water appears even with the supply hose to the bottom of the manifold (drain fitting) disconnected. This suggests water is entering the cylinder(s?) from elsewhere, pretty much all four (1-3-5-7). Can't try a compression test till boat's on the lift or so it seems.
I'd heard VORTEC heads crack from time to time, Pre-VORTEC almost never.
Plan's to remove exhaust that side, get compression test, oil/pickle the cylinders as well as I can. Oddly, the Oil Filler area is not milky and the engine oil doesn't look milky...YET.
Any suggestions, recommendations?
 
I would pull the manifold hoses off the bottom. pull the block drains, remove the water inlet hose from the thermostat. dry the cylinders and fire the motor to dry things.
Usually its a manifold failure to have water in all 4 cylonders
 
Thanks! I'm on may way in that direction. Thought I'd disconnect the water inlet hose at the power steering cooler and run water through the muffs to keep the RW pump happy.

Do you think there's any place to look for a fault in the manifolding? It uses Manifold, 3" Spacer with Studs, and 4" Riser/Elbow. Gaskets are the MerC-type graphite that Sierra/OSCO/West Marine provides with their exhaust now. As I mentioned, less than a full season old.
 
would not be surprised to see a cracked manifold or riser.
A way to do a crude test is to remove the hoses from the manifold
remove the spark plugs
remove the large hose from the therm housing from the therm housing and slowly fill it with water.
If the water level stays the same suspect a manifold /riser issue
If the water exits a sparkplug hole suspect a cracked head or a corroded hole just above a exaust valve
 
Darn JD, be a good idea to fresh water flush what you can.

All cylinders involved is strange to me. There is no exhaust back up is there?
 
alien, Today I ran the engine. Left the manifold and block drain plugs out, disconnected water supply hose from t'stat housing, and made a diverter to send the water from the lower unit past the belts and pulleys into the bilge. Ran water into the lower unit with muffs, but no water was entering the engine. It started and ran fairly well. My plan is to do that a time or two then a compression test. When you said "manifold failure...all 4 cylinders" did you mean Intake Manifold? I read it first as Exhaust, but if there's not water in the oil, all four on one bank are effected, and compression turns out to be good... Leaky Intake Manifold, Water Passage (thermostat housing area) into Intake Plenum?

Bruce, Flushed with SaltAway and fresh water. Squirted oil into cylinders. Then today ran engine about 5-mins. That should have dried it out as alien suggested.
 
One of the boats at my mariner had a problem with water getting into the engine. Turned out to be the intake manifold rusted out. Nice big hole just below the thermostat. Guess it would be a good idea to pull the thermostat and tap the manifold to make sure it is solid.
 
Yeah, most likely exhaust manifold. Intake manifold or gasket leak gets water into the block. Pull the manifold and spark plugs as soon as possible and turn engine over to dry out cylinders then oil them down(2 cycle oil). Inspect manifold and gaskets for point of failure.
 
Oh yeah, I suspect cracking on heads, usually around spark plugs holes, come from People not knowing what they're doing when installing plugs...and over tightening. There are basically two pre vortec heads, classified as heavy castings and light castings. It's a weight saving issue. Heavy castings can be ID'd by straight edge at bottom edge of head. They'd be about mid 70's(or so) and earlier. Light castings have a scalloped edge along the bottom edge.

I bought vortec heads when they were first offered. I think they were $215 each, fully assembled. They are on my 1970 400 ci block.
 
I'll try alien's water testing and see what it reveals. Probably be a couple weeks before I can start. In the mean I'll do a compression test on 1-3-5-7 and post that. If water test shows it's exhaust manifold, PITA but no big deal. But if it's intake manifold, or tear-down shows cracked head... This engine may be a dead end. The TBI looks like it takes MerC 17619 Intake Manifold, NLA. So get a 4-bbl manifold and carburetor. Won't I then need a different Ignition since the TBI uses an ECM? And why not get Vortec manifold and Vortec heads to move this engine into the current millennium? But does it make sense to put all that on a 19-YOA, 1400-hour, flat cam, RWC salt-water block??? If I've got to pull that engine I'll replace it. Probably a Vortec, Roller, Carbed, Delco Voyager Ignition crate engine.
 
Cracked head rarely if ever gets water in all 4 cylinders.

You want to avoid rusting a ring to the cylinder. Dry out and oil them cylinders.
 
Compression Test in 1-3-5-7 order, throttle at WOT, cranking with four plugs out
Dry, having run engine yesterday and cranked it over today before the test - 115-0-30-115
With oil in 3-5 order - 40-65
Repeating the test on #5 twice more - 55 then 50 (#3 didn't change as oil dissipated)

Charlie, I'll squirt oil into #1 and #7 again and crank it over. I didn't do that as part of today's test but I'll get some in there since I'll have to park it awhile to do other stuff.
 
those readings would indicate a bad head gasket between 3 and 5. Yu wont know until you pull the head and see
 
Indeed but did was the head gasket the cause or an effect. Only wrenching will tell.
 
Sorry John, guys. Been having trouble reading the screen so haven't been reading what you've been doing.

Has there been any water since comp test?
 
Charlie, Just do what you can when it comes to the PC and Web. We appreciate you!

No water since, but the engine is drained. Engine block and manifold drains open. Also, the raw water hose (from transom through power steering oil cooler to thermostat housing) is also disconnected then its discharge routed into the bilge. I run water into the Alpha through muffs just to keep the pump wet while I crank the engine. It's only been run once since the water incident. Cranked to spit the water out, then added oil, cranked to blow the oil out and then started the engine. Ran it till the manifolds got hot. Goal was to dry it out as suggested by alien1952. Then the compression tests this morning and oil added after as you suggested.

So... Water? alien suggested a couple tests that I'll try with rust-inhibited fresh water. You can see those above. Intake, heads, whole engine, original 1996 with 1400 salt water hours. Exhaust, SBC MerC-style manifolds, 3" spacers, MerC-style 4" Elbows all new last season. Should be good for this season and maybe one more. 3 seasons, around 300 hours, is about all I can get out of a set of cast iron exhaust parts. Usually, water in 3 & 5 would indicate a leaky wet joint. Could exhaust have failed so catastrophically that enough water dumped into 3 & 5 that the running engine overcame hydrolock and blew the head gasket?

Suggested above, failed intake manifold, water passage into intake plenums... Would that water reach all 4 cylinders on one side? Or front and rear on one side plus two center cylinders on the opposite side? Some intakes were made that way and I don't know how this 2-bbl EFI manifold is constructed.
 
I've seen exhaust manifold cracked so bad from freeze that the engine hydrolocked but I recommended replacing engine rather than even bother investigating further (but I did check dip stick level,full)...but I knew they would junk the boat.

You have clean oil in block so you shouldn't have to go any further than checking that head and gasket.

Did a quick check on prices of vortec heads at Jegs. $313 ea. + free shipping/handling. Can't beat that. I have a used cast iron vortec intake you can have but shipping would probably run you around $75....I've gone to aluminum intake and exhaust manifolds for my FWC.
 
A repair is tempting. I just wonder if it's justifiable to overhaul the top of a block and bottom end with 1400 hours RWC Salt Cooled.

Say I get Vortec Heads and Manifold. OK so far, could use them on a reman short block later. But I still need a Carb and I assume Ignition. It now has a Delco HEI distributor. I don't think (but don't know if) it's same as Delco Voyager. This TBI engine uses an ECM and the ECM gets involved in ignition. Example: Putting ignition into Base Timing using a Rinda scanner. Issues like this, along with this 5.7/350 being flat tappets, makes me wonder if it's time for a re-power.
 
I have a Voyager ignition kit. It has all the components...dist and coil etc. It just didn't work right when I installed it. There's a procedure when hooking up the wiring but there are two opposite installation steps and the wrong one can burn out the ECM. I might have used the wrong one. Check on the price of a new ECM. It might be worth it to buy mine for $100...but only pay if you get it running.
 
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