Blown Gasket on 455!! PLease Help

[jdog]

MY boats been running good ever since I had it. Went to Blythe for fourth of July. Ran great just got back. On Saturday, while pulling the kids on a tube, I noticed alot of milkshake color water in my bilge area. There is obviously alot of water mixed in with the oil. I checked the dip stick, same thing milkshake all the way up tube/dip stick.
I know the usual causes, blown head gasket, cracked block, possible bad leak in pan for the water in bilge area but that don't explain water in block.
My question: The boat still runs good with good compression and no change in temperature gauge. Is there another reason for this that you guys can think of? I will pick up my boat from the river next weekend to bring it home and pull the motor to see if there are any obvious leaks.
What else should I do before tearing apart the motor for a rebuild? I kind of wanted to do this in the winter, not the beginning of summer!!!Shooot.
PLease let me know what you guys would do. THanks Jay

[Wet Dream]

Water pump plate seals, timing cover seals, intake gaskets. The thing that really sucks is that you can either replace one by one to see what fixes it, or do the whole damn thing.

[jdog]

Thanks Wet Dream, what would you do? I'm going to pull the motor to inspect things. Why would it still run good if bad head gasket? and wouldn't I see seepage coming from one of the heads? I'm no mechanic. I don't know?

[Wet Dream]

If you have the tools, do a leak down test on the cylinders. If 2 of them lose pressure fast, its a head gasket. The timing cover and water pump gaskets would be a great place to start if you can't do a leak test. This has been covered a million times, but do you have a gate or ball valve to limit the incoming pressure and flow from the jet pump to the engine? If not, too much pressure will seep past the the gaskets and get into the oil pan.

[Wet Dream]

From the sounds of your first post, it looks like the the engine has held up well for a while. So what you might be experiencing is corrosion that finally ate through the head gaskets or intake gaskets. You can pull the plugs out and see if you have moisture on one or more of them. If you do, you have to do the head and intake gaskets.

[Moneypitt]

What type of exhaust system do you have? Is it possible that the water entered from the exhaust? What kind of motor?......Moneypitt

[Moneypitt]

Sorry, now I see it's an olds, but the exhaust???

[HOOTER SLED-]

Olds are notorious for this. It should be the intake gasket. I've had this happen to me a few times. Make sure you get the right gasket. If I remember correctly, There are different (marine grade I think) types of gaskets. I wanna say the good gasket is like a turkey tray metal one. It's been a while. Use high temp. RTV silicone to seal it GOOD. You'll have to get it on the lake to make a good pass to get the flow of water up. Just keep checking your dipstick. Good luck man
HOOTER

[Builder]

Pull the engine and put it on a motor stand.Drop the oil pan and plug up all the water holes to to the engine except one.Hook up a water hose to that one,turn it on and see where the water is leaking from.It took 24 hours for my 455 to show where the leak was as the water pump plate had to be warm to leak.

[396_WAYS_TO_SPIT]

Ok I will jump in on this one since I just went through this! I had the same problem(with my fresh 455) and I replaced all the gaskets(boy it wasnt cheap). I still got water in the oil. I then ran a second dump line over the back of the transom and the problem was gone. So then I replaced my origional #8 hose with a #10 and went out again. Damn, water in the oil again! I put a pressure guage on the intake manifold and ran it @ wot. I was only showing 10lbs of water pressure comming from the jet, I thought I was fine(Wrong)! I pulled the stick again and wouldnt ya know water in the damn oil again! I then put on another dump line(over the transom) and made a few runs with my gate valve closed a little more. I closed the gate valve to get the engine temp up to boil out the water in the oil and it worked. So now I am drilling another hole in my boat for a second dump line! thats how I solved my problem. I even have one of those fancy "Water pressure bypass valves" and I still got water in there. Change the oil and run a generic hose over the transm and make some runs at the lake. If it clears up then theres your problem. Alot of people beat thier brains up over this situation(like I did). This is just a possibility! The hose and fittings will hit you for about $15.00. What kind of exhaust are you running? Check all of your dump lines to make sure one isnt plugged! This will be the easiest and cheapest way! pulling the motor will set you back. Trust me I just did it twice!
396

[Mark Sims]

Hey 396, where on the motor did you plumb the additional dump line

[jdog]

I can't believe how fast you guys responded to my request for help. THank you Wet Dream, Money Pitt, Hooter, 396, and everyone else who responded. You guys are great!!!!
The exhaust is standard Hardin marine water logs thru-transom exhaust. Now that I think about it I had to stop real hard, even though I have exhaust covers, maybe too much water got through. I dont know.
I do have a gaTE Valve that I installed last year because the motor was running too cold which showed slight water in oil from condensation but nothing like this. It wouldn't even register on the temp. gauge. After I installed the gate valve where the water goes from jet pump to front of engine, it solved the problem. I run it at 180 degrees pretty consistently.
But what would explain all the oil and water in bilge area??
When I bring the boat back, I will change the oil and see If I can find out anything running it in driveway. I will pull the plugs to see if any moisture. I will go from there and use all your advice. I guess I will pull the motor if nothing else works. Thanks guys. JAy

[jdog]

Builder, Your advice sounds good, if nothing works I will pull the motor and pan and do that water leak test.
Hooter your talking about the intake manifold gasket, right? Forgive the stupid question. It's an Edelbrock Performer OLds 455. I'll change that if nothing works. I'll have to do that anyway if it's head gaskets, right?
AND 396, WHAT IS A DUMP LINE??? I"M STUPID WHEN IT COMES TO THIS!! Jay

[396_WAYS_TO_SPIT]

Mark Sims:
Hey 396, where on the motor did you plumb the additional dump line I will take a pic of the line today and post it.
396

[396_WAYS_TO_SPIT]

jdog:
AND 396, WHAT IS A DUMP LINE??? I"M STUPID WHEN IT COMES TO THIS!! Jay A dump line is a line that returns the water out of the block. In your case its the hose comming from the thermostat housing commection to the logs.
396

[HOOTER SLED-]

jdog:
Builder, Your advice sounds good, if nothing works I will pull the motor and pan and do that water leak test.
Hooter your talking about the intake manifold gasket, right? Forgive the stupid question. It's an Edelbrock Performer OLds 455. I'll change that if nothing works. I'll have to do that anyway if it's head gaskets, right?
AND 396, WHAT IS A DUMP LINE??? I"M STUPID WHEN IT COMES TO THIS!! Jay INTAKE manifold gasket correct. No question is stupid. We all had to learn this shit at some point. Even if it is a stupid question, we'll just give you a hard time for askin' just to give you shit. :D :D Hey, when my temp was reading low, I changed out the stock thermostat housing for the Rex thermostat with the bypass. It fixed that problem. I never had a problem with the dump lines like 396. I had a stock intake manifold and heads on mine. Your Edelbrock intake manifold should be fine. If your heads are stock, maybe the ports are kinda corroded. Like I said before, It took me a couple of tries to get that MFer to seal good. I have an extra set of Olds heads if it turns out your in need of some. Maybe yours are cracked?? Good luck man, been in your situation, it sucks.
HOOTER

[jdog]

THanks Hooter. I will keep that in mind about the heads. Maybe the gaskets are getting corroded through since I'm using the boat alot. I think the previous owner just let it sit and they rotted away. Thanks again> Jay.

[Oldsquirt]

Jdog, you absolutely DO NOT want to use that turkey tray type gasket. Look in the Edelbrock catalog and even they will recommend against it. Get a set of Mr. Gasket composition style intake gaskets. Apply a THIN film of silicone around the water ports. I also recommend silicone for the manifold end seals. This will require a test fit of the manifold with the gaskets dry so you can see how much space exists and how large a bead of silicone will be required.

[jdog]

Excellent advice OldSquirt. Thank you. I will use it. Jay

[396_WAYS_TO_SPIT]

OLDSQUIRT:
Jdog, you absolutely DO NOT want to use that turkey tray type gasket. Look in the Edelbrock catalog and even they will recommend against it. Get a set of Mr. Gasket composition style intake gaskets. Apply a THIN film of silicone around the water ports. I also recommend silicone for the manifold end seals. This will require a test fit of the manifold with the gaskets dry so you can see how much space exists and how large a bead of silicone will be required. This guy knows his shit when it comes to olds! Ask him how long his 455 lived! I agree, you have to use a different gasket. also, dont use the rubber gaskets supplied with the set. They will leak. Go to a gm dealer and get the gm silicone. It seals better and it is alot thicker.use it on the water jackets and the front and rear of the intake.
396

[Foolish]

My 455 just got milkshaked too :( I am not sure if its reversion from the headers as the after engine water gate was closed about 1/2 way or its a blown intake. Going to test it out tomorrow. Just for questions sake what's the torque specs for an aluminum manifold and what order do I tq the bolts?

[396_WAYS_TO_SPIT]

Foolish:
My 455 just got milkshaked too :( I am not sure if its reversion from the headers as the after engine water gate was closed about 1/2 way or its a blown intake. Going to test it out tomorrow. Just for questions sake what's the torque specs for an aluminum manifold and what order do I tq the bolts? Rule of thumb is to start from inside to out. They do have a torque spec but if you have a tunnel ram then you cant torque. Go to http://www.442.com/tech/torque.html for all of your 455 olds torque specs. About the headers adding water, the only way to find out is to cut off the water to them. i put a valve on the main header line before the bassett t-valve to cut mine off.
396

[396_WAYS_TO_SPIT]

Here are the pics. They show the extra dumpline(black hose heading tward the transom) and the control valve(to slow or stp water) to the headers. I am running a bassett t-valve but its after the valve in the pic. I had to run this valve so that I could find out if my headers were dumping water into the heads. it does work but if you have pretty chrome headers(unlike mine because I run them dry) then you might not want to run them dry for a long time.Any questions please feel free to ask.
396
http://www.***boat.com/image_center/data/520/239return1-med.jpg
http://www.***boat.com/image_center/data/520/239return3-med.jpg
http://www.***boat.com/image_center/data/520/239return2-med.jpg
[ July 10, 2003, 09:03 PM: Message edited by: 396_WAYS_TO_SPIT ]

[jim lee]

"This guy knows his shit when it comes to olds! Ask him how long his 455 lived!"
Not "lived" because.. Its STILL ALIVE!!
I currently run that motor in my boat. Its even run on the mighty Mississippi!
http://www.banderlog.com/products/waterInjectionValve/images/spitNBailingWire.jpg
Here's a picture of "Franken-Olds" between boats.
http://www.banderlog.com/products/engineStand/images/itRuns.JPG
Don't let the shiny paint fool you.. When Oldsquirt dropped it off, we opened it up and looked inside. It was certanly worn, but it seemd like it would still work fine. So I just bolted the pan back on and painted it. Are we pushing what? 19 years now? Its still running great! :D
-jim lee
[ July 10, 2003, 10:34 PM: Message edited by: jim lee ]