sea water spraying near exhaust manifold

[RMK818]

Hopefully I can get some help here. I have Perkins (79) T6354-U motors and my stbd motor sprays fresh water (not coolant) when running WOT near in between the valve cover and exhaust manifold. the water is significant and poors into the motor drip pan underneath. When cruising at 5 knots, the water does not spray, but I have a very small drip near the last bolt in the rear between the head and the manifold. There is no water reaching the engine drip pans at this speed. Does this mean I need to replace the manifold and gaskets or can I just replace the gaskets? Parts are hard to come by and very expensive.

Thnks,

RMK

 

[ranger58sb]

When you say "sprays fresh water" do you mean sea water? Are you boating in a fresh water area?

(Sorry, dunno where a Clovis might be...)

-Chris

 

[RT Firefly]

Greetings,
Mr. RMK. Welcome aboard. Sounds like a bad head gasket to me.

 

[High Wire]

Seawater cools the oil cooler, transmission cooler, the engine heat exchanger and the exhaust elbow. Depending on the model and year it will also cool an air cooler for air leaving the turbo. Your best bet is to get a diesel mechanic in to take a look. A Perkins doesn’t have seawater going through the cylinder head gasket.
Parts are available through Trans Atlantic Diesel. Have your engines serial number handy when you call.

 

[Circumnavigator]

"Fresh water" confuses me. Usually coolant is "fresh water" and seawater (on a heat exchanger engine) is "raw water".


If the spray is fresh water = coolant, then it is probably a head gasket as RT Firefly suggests. Replace the head gasket.



If it is seawater = raw water, then it's probably the exhaust manifold or its gasket -- Fintry had a 6-354 (originally a generator, then driving the hydraulics) with a seawater cooled exhaust manifold which leaked. You can patch the manifold with epoxy for a while.


Jim

 

[Ken E.]

Is your crankcase oil normal or milky?

 

[koliver]

RMK
As you are in a river, telling us that the spray is fresh water suggests that it is raw water, not engine coolant. As stated above, raw water isn't in the cooling passages, so your leak of raw water is somewhere that you can't yet see and is entering your view in the location you have described.
I have seen this occur where the leak originated from the exhaust elbow, where a leak from the hidden portion of the elbow allowed raw water to show on the exhaust manifold and drop into the tray below. I found the source by using my cellphone camera to take a series of pictures and there it was! That was on my son's boat 8 years ago. Sorry, the pictures were deleted when the repair was complete.
You need to investigate further.

 

[FlyWright]

Pull the manifold and find out. Running it like that can do damage.

 

[RMK818]

Chris, it is seawater. The boat is kept out on the California Delta (Oxbow Marina) in Fresh water.

 

[mvweebles]

. Does this mean I need to the manifold and gaskets or can I just replace the gaskets? Parts are hard to come by and very expensive.

Picture would definitely help. Does sound like a head gasket. But if your engine has a combined "mani-cooler," and leak is from there, replacement could be difficult.

TAD diesel is my go-to for Perkins parts.

Good luck

Peter

 

[Circumnavigator]

Picture would definitely help. Does sound like a head gasket. But if your engine has a combined "mani-cooler," and leak is from there, replacement could be difficult.

TAD diesel is my go-to for Perkins parts.

Good luck

Peter

It's raw water, not coolant, so it is not a head gasket -- no raw water goes through the head gasket. As I said above, if the exhaust manifold is raw water cooled -- as it was on Fintry's 6-354 -- it's probably a hole in the water jacket.


Jim

 

[mvweebles]

It's raw water, not coolant, so it is not a head gasket -- no raw water goes through the head gasket. As I said above, if the exhaust manifold is raw water cooled -- as it was on Fintry's 6-354 -- it's probably a hole in the water jacket.


Jim

Point taken. Of course.

Aren't holes in water jacket typically on inside though? Gasket leaks would more normally be manifest as an external leak? A picture would still be helpful. And a bit more info - 6.354 with mani coolers are a special breed, if that's what the OP has

 

[Brooksie]

It's raw water, not coolant, so it is not a head gasket -- no raw water goes through the head gasket. As I said above, if the exhaust manifold is raw water cooled -- as it was on Fintry's 6-354 -- it's probably a hole in the water jacket.


Jim

I agree.
It would help to know which manifold he has and if horizontal or vertical model. So as mentioned above, a picture might be in order. But I think he has moved on...

 

[Benchmark]

A possibility exists it could be back pressure caused by a plugged exhaust component!


Like an exhaust riser or elbow, where the spray holes have partially or fully plugged up.

 

[RMK818]

I am trying to load some pictures of the issue, but am struggling. I did see the inside of the manifold has sever corrosion near the Valve Cover.

 

[RMK818]

Trying to load pictures but not having much luck

 

[RMK818]

Update: Sea water spraying near exhaust manifold

Thank you everyone who provided assistance. Here is an update to my situation: Had a Diesel mechanic look at the motors and he confirmed it was the exhaust manifold and not to run the motor until fixed to prevent any further damage. I was able to get the parts from TADiesel.com and from LCS Marine. Total came to 1100 which consisted of a manifold (Barr) and a gasket kit. It was also recommended that I replace the 90 degree can elbow on both motors (1400 total two stainless steel elbows, clamps and seals). Labor has not yet been factored into the cost of the repair. Anticipating 3,000 for that. All in all it looks like a 5500 dollar repair job.

Thanks again for everyone's help