502 king cobra water in oil

[Firefighter3011]

I have a 1992 chris craft with a 502 king cobra engine set up. the stern drive and transom mounting is stock however the engine is a crate 502 which was built and installed last year in the previous owners possession along with a set of stellings water injected headers and gaffrig external switchable mufflers. I have had this boat out a total of 10 days the end of this season putting a total of 14 hours on the engine on top of the 32 hours when I bought it. The engine ran very well during all these times out but ran cold my temperature gauge starts out at 100 degrees and the gauge didn't even come up off of that. During a hard 55 mph run even. I could reach down and touch the intake and thermostat housing with just being warm to the touch. same with the two oil filters. This brings me to my question. I figured the thermostat was stuck open and would take care of it when winterizing. well when I took the thermostat housing off there was no thermostat installed. afterwards I found the thermostat in a storage compartment in the boat and plan to install it next season. Now this being said I went and changed the oil and it was milky with water. it also smelled like gas/combustion very strong when it was in the pan. PCV valve had white sludge on it and so did the breathers and oil caps. Now I ask could this all be caused by running this engine without a thermostat and not boiling off the water and combustion by products out of the oil ? would 14 hours of running build that much condensation? I have since changed the oil and the boat is winterized so I cannot put a load on the engine with the thermostat to bring it to operating temperature to see if problem continues. I realize this can be from a bad intake gasket and/or bad head gasket/ cracked block. I highly doubt though that the block would be cracked and or the head gasket or intake would be leaking due to it being a newly built engine. the block was drained when I picked up the boat. i plan to do a compression test in the spring before i take the boat back onto the water and pressure test the water jackets to test but does my assumption sound correct and possible that the milky oil could be caused by extremely low oil temperatures? Thanks in advance

 

[HT32BSX115]

Re: 502 king cobra water in oil

Howdy,


Welcome aboard!



depends on how much water is in the oil whether it's a cracked block or not. Although to be sure, you should pressure check the entire cooling system.

Operating without a T-stat, would not cause water in the oil. It would cause the engine to run WAY too cold though.....and if there was water in the oil previously, the engine probably wouldn't get hot enough to boil it off .


It's possible that you have a head gasket problem, but you should pressure check the cooling system first. Water in the oil is almost always due to a cracked block. If it's freeze damage, they crack internally. under the intake manifold right next to the push-rods.

Also, if that boat was sitting in the weather, water could have gotten into the engine from running into the carb.... I think that is fairly unlikely unless you had it sitting with no flame arrester on the carb and the engine cover off etc.....Not many people would leave their brand-new engine exposed to the weather!

If you have a poor intake manifold fit and/or poor gasket seal, water might get in the valley that way.

In any of the above instances, a cooling system pressure check will reveal leaks. The engine should hold 15-20 PSI.



You have a rather unique drive. Unless you have an engine mounted raw water pump, you'll want to consider one in the future.

Your impeller is not available. (There's a few NOS[new-old-stock] ones on ebay for $100-200 and more.......some dealers with old ones sitting on the shelf are just trying to rip people off.....)



But more important, treat that drive with "kid-gloves"...... There are a lot of hard parts inside that cannot be obtained unless you have a parts drive to cannibalize.


Another suggestion........put some paragraph breaks in your posts and it will be easier for us to read!



Regards,



Rick

 

[jerryjerry05]

Re: 502 king cobra water in oil

The motor you have has an oil cooler.
It can leak into the system and cause the water in the oil problem.
The riser/manifold can crack and leak through the valves and cause the problem.
Pull the plugs and check for water/rust.
Comp test?

 

[HT32BSX115]

Re: 502 king cobra water in oil

The motor you have has an oil cooler.
It can leak into the system and cause the water in the oil problem.
The riser/manifold can crack and leak through the valves and cause the problem.
Pull the plugs and check for water/rust.
Comp test?

I have a 1992 chris craft with a 502 king cobra engine set up. the stern drive and transom mounting is stock however the engine is a crate 502 which was built and installed last year in the previous owners possession along with a set of stellings water injected headers and gaffrig external switchable mufflers.

if he's using these "headers, There's no riser/manifold gaskets and no leaks (unless there's cracks in his new manifolds)

An oil cooler CAN leak............ and water can get from the oil cooler to the oil system, but only if the cooler is below the water-line AND the boat is moored in the water!

When you run the engine, since the oil pressure is FAR higher than the water "pressure" could ever be, water cannot overcome the oil pressure and the owner might notice the loss of oil before noticing the water in the oil...... To verify that, look for a multi-colored "slick" behind the boat!

If the oil cooler is in the same place as mine was on my 460, it's pretty close to the waterline or above it.

When you do the cooling system pressure check, leave the oil cooler inline with the cooling system. If there's a leak, it'll reveal itself!

 

[Firefighter3011]

Re: 502 king cobra water in oil

thanks for the reply's. you guys opened up some new questions I have had I am going to try and recap everyone's advice. might be lengthy I apologize in advance lol.

To Rick:
There isn't enough water in the oil to make the level rise on the dipstick it was more of like streaks of water when I pumped out the oil. The oil that was in it was amsoil 30 weight and was pretty clear from the start before I picked the boat up. you could tell it had water in as well as removing the PCV valve and the filler caps and could see the foam on the caps and such. I spoke with a marine mechanic today that I work with and he said it very well could be caused by extremely low oil temperatures as I also spent a good bit of time idling around in no wake areas in the city. like I said after running WOT the temperature gauge did not even register and the oil temperature did not reach 120 degrees. Blow by/ condensation cannot be vaporized if the oil isn't up to temperature.
The oil is just being cooled by the fresh supply of 65 degree river water. I could be wrong but I hope I am not. I find it really hard to believe that this engine was just built last year and the head gasket/intake gasket/ and or block is cracked being that the block was dry when I picked the boat up. The drains were completely removed.

Now onto the drive lol . Yes I know this drive is an extinct figure and I've already accepted the fact that if internals go that its going to be buying a used/remanned drive or adapting over to a merc. It is going to be costly no matter what happens. I drained the oil out of it the other day and it was perfect. Little material on magnet on drain plug but the rest was clear and no water intrusion. So I guess that is a plus. Now a question that I might ask is I have found out that there is no outdrive gasket for a king cobra. only regular cobras. From what I gather the tapered u joint bearing carrier snout is what fits into the pivot housing and greasing this makes the water tight seal? any input? ive consulted an OMC guru at my local marina and he says this is the case that it is a precision tapered fit and with a little triple guard grease the seal is made.

When I removed the outdrive to inspect bellows/gimbal/u joints the tapered ends were all corroded and signs of leaking as well as bellows full of water. I have since replaced bearings and u joints and have assembled it per the manual and will wait until next year to see if my seal job worked. As far as the raw water impeller I had to buy a housing and impeller when I purchased the boat and have since found two impellers in the boat one being new and one being slightly used. So I hope that can give me a few years of use out of those parts.

I will be pressure testing the cooling system when i remove the boat from storage in the spring for as easy of a procedure that is and doing a compression test as well . Hell the spark plugs are all going to be replaced anyway so why not take a few more minutes to do a comp test



Jerry:

Correct me if im wrong here. I did consider it being an oil cooler but the thing is a lot of things on a stock king cobra are removed from this crate engine. The transom water supply hose from the drive comes directly up to the block. There is no power steering cooler or oil coolers along this inlet hose. I have scanned the sides of the block for block mounted coolers and it is a bare block on either side. So if theres anywhere else these coolers could be let me know. The engine builder also eliminated the circulatory pump and installed a pump bypass system made for the 502. It pumps water directly from the impeller into the block and then there is two bypass hoses that continually run water to the headers in the event that the thermostat is closed. and for the 3rd there are transom water pickups that are "T"d into each header. so I don't think I will ever run out of cooling water and yes there Is jacketed marine headers installed with gaffrig silencers when the boat is in the water the tip of the silencer is about 2 inches above the water. on the inside there is about an 8 inch rise that goes up to the header collector so even in the event of a wave or coming off plane hard there is no way there would be any water to get into the headers.

I wish I could post a picture somehow
Crossover Kit :: Crossovers & Thermostat Housings :: Cooling Systems :: Diamond Performance Parts

 

[HT32BSX115]

Re: 502 king cobra water in oil

The transom water supply hose from the drive comes directly up to the block. There is no power steering cooler or oil coolers along this inlet hose.

That's where they'd be if you had them. If you suspect there was any water in any combustion chamber, you SHOULD remove the plugs and crank the engine to clear it and then spray some light oil in there before screwing them back in. You do not want water sitting on top of pistons while the engine is stored.

If you ran it before you put it away, you can probably rest assured that there is no water in there though.

There isn't enough water in the oil to make the level rise on the dipstick it was more of like streaks of water when I pumped out the oil.

If all you saw was some water/oil emulsion on the oil fill cap, breather hose etc, I wouldn't worry about it too much. Sounds like it's more from condensation than from an actual leak.

Before you pressure check anything, get the T-stat (suggest 160 degrees) back in there, with clean oil and run it.

There might be a little water left in the pan, but it will evaporate out fairly quickly when you run it at normal temp for a while.

I would suggest getting a PS cooler. There's really no way to dissipate heat in the PS system (like a car that has good airflow in the engine compartment)

Excessive heat can damage PS actuators.

on the inside there is about an 8 inch rise that goes up to the header collector so even in the event of a wave or coming off plane hard there is no way there would be any water to get into the headers.

Mercury actually has a minimum acceptable riser height (water line to top of the riser) that must be complied with to prevent reversion. (from sudden stoppage, waves, etc) I don't know it off the top of my head but if I can find the Mercury installation manual, I'll post the source.....they actually make 3, 4 and 6inch riser extensions I think. More is always better...... I know that doesn't help you with your fixed height risers, but yours might not be a problem if the thru-hulls are not actually IN the water. (although it's sometimes a problem when you "beach" a boat and a big wave comes by)

The problem is more pronounced with thru-prop exhaust using a Y-pipe etc.

 

[Bondo]

Re: 502 king cobra water in oil

That's where they'd be if you had them. If you suspect there was any water in any combustion chamber, you SHOULD remove the plugs and crank the engine to clear it and then spray some light oil in there before screwing them back in. You do not want water sitting on top of pistons while the engine is stored.

If you ran it before you put it away, you can probably rest assured that there is no water in there though.




If all you saw was some water/oil emulsion on the oil fill cap, breather hose etc, I wouldn't worry about it too much. Sounds like it's more from condensation than from an actual leak.

Before you pressure check anything, get the T-stat (suggest 160 degrees) back in there, with clean oil and run it.

There might be a little water left in the pan, but it will evaporate out fairly quickly when you run it at normal temp for a while.

I would suggest getting a PS cooler. There's really no way to dissipate heat in the PS system (like a car that has good airflow in the engine compartment)

Excessive heat can damage PS actuators.



Mercury actually has a minimum acceptable riser height (water line to top of the riser) that must be complied with to prevent reversion. (from sudden stoppage, waves, etc) I don't know it off the top of my head but if I can find the Mercury installation manual, I'll post the source.....they actually make 3, 4 and 6inch riser extensions I think. More is always better...... I know that doesn't help you with your fixed height risers, but yours might not be a problem if the thru-hulls are not actually IN the water. (although it's sometimes a problem when you "beach" a boat and a big wave comes by)

The problem is more pronounced with thru-prop exhaust using a Y-pipe etc.

Ayuh,.... I agree with ya Rick,... The bit of water is most likely just condensation from runnin' a stone Cold motor,....

The tippin' point of the risers should be 13" above the water line, outside the hull,....

Welcome Aboard Firefighter,....

 

[Walt T]

Re: 502 king cobra water in oil

Never ever assume just because it's new and the exhaust system gaskets and stuff are all new and freshly installed that they can't be a source of a problem. Boy I've been down that road so many times I've learned to disregard customers saying "The last mechanic replaced the muffler bearing so it can't be that!"

Definitely not saying that's your problem, I saw that line in your post and just wanted to remind the techs and guys posting questions here about that old line about ASSUME.

 

[jerryjerry05]

Re: 502 king cobra water in oil

The stock motor came with oil cooler and a PS cooler.
Whoever removed yours probably didn't do you any favors.
I have seen them go bad and leak into the oil.
Like bondo suggests put them back.
As far as the exhaust getting water back in?
Is there a flapper or someway to stop the back flow?
It's not always: it does this? so that the problem!

 

[Firefighter3011]

Re: 502 king cobra water in oil

I do agree some testing needs to be done next year before the pleasure part comes into play. it was more water then just on the breathers and pcv valve and caps. The oil definitely had some water in it when I took it out but it was hard to tell how much. I had ran the engine for 10 minutes before I extracted the oil and it just looked streaky as it was coming out the extractor discharge. It wasn't foamy or anything you could just tell there was some water in it. But the fact that it didn't "make" any oil in the whole half a season I ran the boat on that oil makes me feel a little better.

The thermostat I found in the boat in a Ziploc bag is a 140 with 3 holes drilled in the flange. This maybe the happy medium for the temperature this engine was susposed to be run at since it considerably built up and not a bone stock engine. What I am going to do is try that thermostat first and take coolant and oil temperature recordings and see if I need to install a 160 to get the oil and block at a hotter temperature. I really don't see a reason for the holes drilled into the thermostat flange being that I have a bypass for each header if the thermostat is closed but maybe without the 3 holes it was running too hot for the last owner. Not sure on that one and wont find out until spring. In the meantime im going to buy a new 140 (with no holes) and a 160 so that im ready for testing

Same goes with the power steering , I know it should have one but if I run the boat for an hour steering rather frequently and take a reading of the temperature of the oil in the pump , if im happy with the temperature then I will leave it without one. if its running too hot then I buy one and install it.

Walt, good advice I totally agree with you but like Rick said im not going to jump to conclusions until I get this oil up to temperature and see if the water/condensation issue continues. If it does then comes the pressure testing/ compression testing.

The engine was ran before winterizing and was fogged out/drained/and filled with antifreeze. so it was hot and run right before closing up shop for the winter. No real reason I needed to winterize the boat since its going to underground storage this weekend but I really didn't like the idea of the block sitting dry. I know its not going to hurt anything but i'd still just rather spend a few dollars on antifreeze and keep some liquid in there as well as the raw water pump in the outdrive. don't know if this helps keep the impeller from drying out or not but it was my theory and that's what I did.

And no there isn't a flapper in the exhaust . If you look at the pictures I posted you can see the angle that goes down through the transom. on the outside of the transom there is a "can" silencer on each header that are angled down towards the water but are about 3 inches above the water line. If you look at the angle and visualize it its a SIGNIFICANT rise to get to the header collector . There are pneumatically controlled butterfly valves on each silencer can that directs the water down through a small cutout in the bottom of the muffler and into a custom fabricated stainless shroud that he had made that goes down below the water line and seals the transom. kind of like a chute. but this can only be used at idle only because it is not near enough opening to let more then idle gasses out.