Inline 6 250, 165hp water in oil

[gregg_a_g]

The "new for me" inline 6 came off an old timer's boat that had been sitting in
a garage (apparently heated) since he had some health issues several years back.
My "free boat" had a cracked block. I checked the dip stick when I got the engine and
it was "only black", no sign of water whatsoever. The riser elbow was pretty rusted,
and it had been removed, but was packed with the engine. I put on the elbow from the engine with the cracked block (riser and manifold look good to my untrained eye).
Cranked up the new engine on a pallet and it sounded like a tiger purring.

I ran it for several minutes and it just hummed along. Accelerated just for a moment a couple of times, and there was instant power without any hesitation. I shut down and decided to change the oil. Now the dipstick was that color we don't speak of - kind of grey and milky. I drained the oil and it was slushy grey. I refilled the engine, ran it a bit, and drained the fresh oil. A little thin, but black, not grey.

A few thoughts come to mind-
1) Cracked block - say it isn't so! The block, heads and oil pan are pristine. No signs of exterior cracks. I hope this isn't the problem...
2) My water pressure (I ran a hose into the water line that would normally come from the impeller on the outdrive) may have been too high. But I ran only a modest amount of water, although the water was pretty cool at the exhaust. Could too high water pressure cause water to flow back into the manifold and get into the oil somehow?
3) Crack/leak/hole in manifold - I like this the best because I have another manifold (from the old engine) and could switch it out. Since the riser elbow was rusted pretty badly, I'm thinking that the manifold may have been compromised as well. Maybe that's why the previous owner had taken it apart (before, or maybe at the beginning of Alzheimer's).

Any ideas, suggestions for further diagnosis? I'm surprised that the engine could start so easily and sound so good with this kind of major issue!

Thanks for your ideas!

 

[kenny nunez]

Pull the valve cover and check that the head is not where the leak is,
sometimes that is where water will leak through a pin hole in the casting. I have even seen water come up through a head bolt that was not sealed with #2 Permatex.
The other common place is at the base of one of the cylinders where the casting is the thinnest.
Try to seal off the block and test it with some air pressure.

 

[gregg_a_g]

Thanks Kenny. So since the engine sat for several (maybe many) years, do you think that the head gasket or head bolts might be leaking? Do you normally put in Permatex in all the head bolt holes?

If it's the base of the cylinder, that means the block is kaput, yes?

If I remove the valve cover and turn the hose back on to the raw water supply line, I should be able to see if the head bolts are leaking, but not necessarily the head gasket - is that right? I mean the head gasket might seal to the outer edge of the head, but it might be leaking inside, yes?

The "block air test" means sealing off the input hose for the raw water, and then the water outlet at the riser elbow?

Would a leak/hole in the manifold still be a possibility? After I remove the valve cover gasket (easy), I could remove the manifold and inspect.

Thanks for your help!

 

[Scott Danforth]

acetone check your used manifold and riser however if the block was cracked on the free boat, so were the manifolds. the reason blocks crack is the exact same reason manifolds crack : lack of winterization

pressure check the new to you motor should hold 15-20 psi all day long

since you put the manifold and riser from the cracked junk motor on your new to you motor, bet you found you put cracked junk manifold/riser from your junk motor on the good motor

 

[gregg_a_g]

Hi, Scott. How do I "acetone check" the manifold/riser? I only used the "riser/elbow" from the old engine because the riser on my new engine didn't look so good. I did not replace the manifold - the new engine was complete except for the riser (removed, but doesn't look good).
15-20 psi in the engine - does that mean block off the water inlet and outlet, and then try to put in air pressure through the water hose, like with a schrader valve?

 

[Scott Danforth]

15-20 psi in the engine - does that mean block off the water inlet and outlet, and then try to put in air pressure through the water hose, like with a schrader valve?

yes

to acetone check, you fill up the elbow with acetone and see if it leaks thru.

you may have to build a block-off plate and use gaskets

personally, i would just buy a new elbow

 

[gregg_a_g]

I will eventually get a new elbow, but want to make sure the block is not toast before spending on the elbow.

I'm a relative newbie, so not quite understanding the riser/elbow flow.
There are 3 oblong holes in the bottom of the elbow. Do I turn the elbow upside down, then fill the 3 oblong holes with acetone, and see if they leak into the main part of the elbow (indicating a leak/hole in the internal passageways)? What would I do with the block off plates/gaskets?

If I can figure out where the water is getting into the oil (and assuming it isn't a cracked block) I can get new parts. If it's a cracked block, I'm kind of sunk for now.

 

[Scott Danforth]

If I can figure out where the water is getting into the oil (and assuming it isn't a cracked block) I can get new parts. If it's a cracked block, I'm kind of sunk for now.

start with pressure testing the motor. take the line from the exhaust manifold and the line from the transom shield and tee them together. put a pressure gauge and a schroeder valve

make sure the cooling water jacket is empty

pressurize to 15 psi

 

[gregg_a_g]

Pressure test sounds good. So the rubber connector from the riser elbow is pretty big. I have a bunch of PVC pipe, so maybe I can get the other end of the riser elbow rubber onto a piece of PVC and then tee the inlet water hose onto the PVC. Then get a gauge and air line into the PVC pipe.

Or I could make a little metal blank plate between the riser and manifold. And then just need to put an air fitting on the raw water hose. Is that how to do it?

 

[gregg_a_g]

Ah, okay I have a better idea. I found a 1/8 plug at the bottom of the manifold - so I removed it to drain the water. There is also a plug in the block- so I'll drain that also. Seems like the easier way to pressure test is to connect to the 1/8 hole on the manifold and just block the raw water hose and riser rubber bellows, yes?

 

[gregg_a_g]

Aargh! Good news, and bad news. The block drain plug is 1/4, but it sheared off. Guess I need to drill/extractor it out. Ha, ha - nothing is easy!

 

[Scott Danforth]

Pressure test sounds good. So the rubber connector from the riser elbow is pretty big. I have a bunch of PVC pipe, so maybe I can get the other end of the riser elbow rubber onto a piece of PVC and then tee the inlet water hose onto the PVC. Then get a gauge and air line into the PVC pipe.

Or I could make a little metal blank plate between the riser and manifold. And then just need to put an air fitting on the raw water hose. Is that how to do it?

Stop. What you are thinking wont work

Ah, okay I have a better idea. I found a 1/8 plug at the bottom of the manifold - so I removed it to drain the water. There is also a plug in the block- so I'll drain that also. Seems like the easier way to pressure test is to connect to the 1/8 hole on the manifold and just block the raw water hose and riser rubber bellows, yes?

No

Ignore the manifold and elbow for the pressure test. In fact, unbolt them

Pull the 1" supply line from the transom shield and the coolant supply hose to the exhaust manifold and tee together to pressure test the block

Unbolt the exhaust elbow from the manifold put on your workbench and acetone test it. If there is a crack, acetone will seep from the water jacket side to the exhaust side. You will need a block off plate and gasket for the manifold mounting surface. You will need to plug any threaded port, and prop up to fill cooling jacket side with acetone

Unbolt the manifold from the head, put on your workbench and acetone test it. You will need to block off the elbow mounting surface with a plate and gasket. You will need to prop up to fill manifold cooling jacket with acetone

 

[gregg_a_g]

Thanks, Scott. I see what you are saying now. I was confused...
If I had the head and manifold in the loop, there wouldn't be anywhere for air to leak because i would be pressurizing both sides - doh...

Still not quite visualizing the elbow/manifold procedure. I'll work on the
block test first. If there is an air leak in the block, how will I know if it's from a cracked block, leaking head bolt or gasket? Should I remove the valve cover and use soap bubbles? I pulled the spark plugs and they don't look too bad.
I don't think I see water in the cylinders - just a little oil, not drops or a puddle, but like a coating.

 

[Scott Danforth]

Pressure to 15 psi

If it holds pressure, you are good

If it doesnt, listen for escaping air

 

[gregg_a_g]

Okay, I think I got all the necessary plumbing parts and got things connected correctly to pressure test the block. Put 15 psi into the tee and noticed quite a bit of water leaking. Looks like the first thing to do is to clean the hose connections at the circulating pump and eliminate those leaks. When I had the engine running there were no leaks there, but I guess it was quite a bit lower pressure.

Once I get the gross leaks fixed, I'll start looking for the leak that might show me where the water is getting into the oil. I'll remove the valve cover and look around the head bolts, head gasket and oil dip tube. If it's a big leak, I should be able to hear it, yes? If not so big, should I use soap bubbles?

 

[gregg_a_g]

Making progress on pressure test. I found 3 gross leaks on the input/out to the water circulation pump, and on the cap for the circulation pump. Got 15 psi in the system but it leaked down 10 psi in about 15 minutes. I found another gross leak on the raw water input line to the thermostat housing. When I ran the engine last weekend I didn't notice any water leaks - maybe I was just too excited to see and hear the beast running.

Once I lightly sanded all the metal hose barbs, and then did the same to the inside of the hoses, I stopped or reduced the leaks significantly. I couldn't see any bubbles from my soap solution. Pressured back up to 15 psi and it leaked down almost 2 psi in about 90 minutes. I will definitely be replacing the old hoses and clean/polish the barbs a bit more thoroughly.

Is 2 psi in 90 minutes "good news" as far as possible block cracks/leaks?
Didn't hear any air around the head bolts. Couldn't see any bubbles either.
I didn't get the torque wrench out, but they feel like they're close to 95 ft-lbs
with the ratchet. I'll find the torque wrench tomorrow.

If 2 psi in 90 minutes is not quite definitive, I'll re-seat the hoses where
I found the gross leaks and tighten up my test setup to make sure that's
not leaking.

If the block and head are not leaking, does that mean I would need to focus on the manifold and riser next?

Thanks for all the help! I'm hoping that the block/head are good!

 

[Bondo]

Ayuh,..... Don't start new threads about the same topic,.....

Thank you,.....

 

[gregg_a_g]

Sorry, Bondo. I wasn't sure if "long threads" got lost and forgotten. I'll be more patient! The advice and help here has been invaluable.

 

[gregg_a_g]

Didn't hear any air escaping or see any bubbles around the block or head, so I redid all the test setup connections. Sure enough, my setup was at fault. After using teflon paste on my threaded connections and tightening a little more, I pressurized to 16 psi. Less than 1 psi leak down after 4 hours, and it's cooling off quite a bit, so that would account for part of the reduction in pressure!

I'm pretty well convinced that the block is okay. I'll move on to the manifold.
Before I take it off to do an acetone test (finally understand what that's all about), I'm planning to put a blank gasket on the riser and do a pressure test
like on the block.

The riser came off the engine with the cracked block (from not winterizing at all, and letting sit for 3 years - and yes, we got some sub 20 deg days during that time). So it seems likely that the riser is kerflunken, but I want to check the manifold first since that's next in line.

 

[nola mike]

Didn't hear any air escaping or see any bubbles around the block or head, so I redid all the test setup connections. Sure enough, my setup was at fault. After using teflon paste on my threaded connections and tightening a little more, I pressurized to 16 psi. Less than 1 psi leak down after 4 hours, and it's cooling off quite a bit, so that would account for part of the reduction in pressure!

I'm pretty well convinced that the block is okay. I'll move on to the manifold.
Before I take it off to do an acetone test (finally understand what that's all about), I'm planning to put a blank gasket on the riser and do a pressure test
like on the block.

The riser came off the engine with the cracked block (from not winterizing at all, and letting sit for 3 years - and yes, we got some sub 20 deg days during that time). So it seems likely that the riser is kerflunken, but I want to check the manifold first since that's next in line.

My risers were fine from the engine I got with cracked block/manifolds.