Water in the intake

[Erico624]

Hello, i have a 1999 GM 5.7 marine motor, with Indmar intake. Looking for the best gaskets to get. It has a heat exchanger freshwater. Raw water cools the exchanger. I have water when i pulled intake pulled dipstick milky. I have the black rubber gaskets with metal. I did not add silicone to the water ports.

 

[jimmbo]

Most Gaskets for the Vortec are quite good, and do not use glue or sealant

Just wondering, the Title was "Water in the Intake" If water is in the oil, there are several ways it got there, usually Cracked Heads/Block

 

[04fxdwgi25]

Most Gaskets for the Vortec are quite good, and do not use glue or sealant

Just wondering, the Title was "Water in the Intake" If water is in the oil, there are several ways it got there, usually Cracked Heads/Block

or bad exhaust manifold leaking back past exhaust valves.

 

[Chris1956]

So freshwater cools the manifolds and raw water cools the risers? Is raw water salty? Probably the manifold is still good, if freshwater use. I would look at the risers, especially the joint between them. If any water goes past the gaskets on the manifold to riser joint, it can end up in the cylinders and oil. Also, 1999 is a long time for risers to last, if salt water cooled.

A lot of those V8 blocks had water cooled intake manifolds. Maybe a leak there? I have no idea how likely that is.

 

[Scott Danforth]

Use Felpro for the gasket.

if you have water in the intake, you have a leak somewhere.

if you have water in the exhaust, check the condition of the manifold to elbow joint.

 

[Erico624]

This is a complete rebuild. Has not touched saltwater yet. Was a freshwater engine from a 2000 mastercraft with low miles.

 

[Erico624]

So freshwater cools the manifolds and raw water cools the risers? Is raw water salty? Probably the manifold is still good, if freshwater use. I would look at the risers, especially the joint between them. If any water goes past the gaskets on the manifold to riser joint, it can end up in the cylinders and oil. Also, 1999 is a long time for risers to last, if salt water cooled.

A lot of those V8 blocks had water cooled intake manifolds. Maybe a leak there? I have no idea how likely that is.

Salt water cools the heat exchanger

 

[Erico624]

Use Felpro for the gasket.

if you have water in the intake, you have a leak somewhere.

if you have water in the exhaust, check the condition of the manifold to elbow joint.

The cylinder walls are dry of the water is in the intake.

 

[Erico624]

Here is the pics. The pictures finally work.

 

[flashback]

That is the lifter valley IMHO... the water could have come from anywhere and was circulated with the oil and settled there.. you have a problem. And it could be an intake leak but don't exclude the other causes. There are many.

 

[Scott Danforth]

That is water in the crank case. Potential sources:

Cracked block
Cracked head(s)
Failed intake manifold
Failed exhaust manifolds
Cracked intake
Leaking intake manifold gasket
Leaking head gasket

 

[Erico624]

That is the lifter valley IMHO... the water could have come from anywhere and was circulated with the oil and settled there.. you have a problem. And it could be an intake leak but don't exclude the other causes. There are many.

Where should i start?

 

[Erico624]

That is water in the crank case. Potential sources:

Cracked block
Cracked head(s)
Failed intake manifold
Failed exhaust manifolds
Cracked intake
Leaking intake manifold gasket
Leaking head gasket

Where do i start to test?

 

[Scott Danforth]

Since you already yanked the intake, you can not pressure test.

Pull the exhaust. If you have rust streaks in the ports, then you have leaking exhaust manifolds

I myself would be pulling the motor and do a full teardown and inspection

 

[Erico624]

Since you already yanked the intake, you can not pressure test.

Pull the exhaust. If you have rust streaks in the ports, then you have leaking exhaust manifolds

I myself would be pulling the motor and do a full teardown and inspection

The motor is out and i did a full tear down. Been running it on wheel dolly.

 

[Erico624]

Since you already yanked the intake, you can not pressure test.

Pull the exhaust. If you have rust streaks in the ports, then you have leaking exhaust manifolds

I myself would be pulling the motor and do a full teardown and inspection

 

[jimmbo]

You gotta replace the Coupler, it is really wobbling badly
What kind of Machining was done to the Heads/Block?
Who put the Engine together?

 

[Erico624]

You gotta replace the Coupler, it is really wobbling badly
What kind of Machining was done to the Heads/Block?
Who put the Engine together?

I put the engine together. Build from block up. Honed piston chamber’s. Measure got right sized rings. Replaced all gaskets.

 

[Erico624]

You gotta replace the Coupler, it is really wobbling badly
What kind of Machining was done to the Heads/Block?
Who put the Engine together?

Not sold on these intake rubber gaskets. Heard bad things about them.

 

[jimmbo]

Did you check the Heads for Warpage, and Resurface if necessary?

Not sold on these intake rubber gaskets. Heard bad things about them

The entire Gasket is not Rubber/neoprene/Silicone, it is usually Plastic, with Rubber/neoprene/Silicone Rings around any Ports.
If the Block-Heads were machined, then Holes in the Gasket may no longer match the Ports on the Intake.

An Acquaintance acquired a Boat and Motor, as part of a Trade. "Runs Great!", he was told. He was convinced he needed Head Gaskets, even after I took this Pic. Actually he did need new Gaskets, as well as a new Block and Heads
Since you have the motor out of the Boat, I agree with Scott, that it has to come apart for a very thorough Inspection.