Overheat light but ok temp and oil pressure

ok great! Thanks.

I did the Ultra Black and it is working well, Totally dry. What I had done before, that caused the leak, was the rubber seals that come with the intake manifolds. One squeezed in so it left a perfectly open section, worse than if you had not used a seal at all.
But.....
I noticed that my intake manifold doesn't' use all the last set of cooling channels. Does this matter? Is the engine dependant on this to get even head cooling or is it just for the intake manifold if it wants it?

Mark,
Thank you. That is very helpful. I pulled the intake off last night and saw that I had used the pre-made provided rubber china wall seals. They just got squeezed out (to the inside) leaving a big gap perfectly open for oil to flow out. So I will use the Permatex ultra black as mentioned.
I watched several videos on small block intake manifold installs. When you see that each pro has their own special recipe you know it is a tricky assembly. THere was all kinds of crazy advice. One guy used the provided pre-made rubber seals, looked at how they squeezed and knew he needed to pull them out and then use just silicone. So basically what I'm doing except he did that full cycle in 30 minutes and mine is over a year and a half. The difference between us is that he knew to look at how the seals seated. Now I have that experience.

JQ, Thank you that is great
Adam

Ughhhhhhh!!!! I put a new pressure sensor in and I still got oil from it. So I took out the sensor and put a plug in it to see more closely what is going on. I cleaned around the plug so it was dry. I watched it and had my wife rev to 3K RPM. The oil is coming from under the intake manifold??? I marked it with a red line in teh picture. Is there even an oil channel in there? I did replace this intake manifold when I put the carb on, but I don't recall an oil channel running through it.
The red arrow points out the seal location between the manifold and block.

A failing sensor could certainly provide an oil leak.

It looks like the oil is coming from the top of the sensor. I am crossing my fingers that is it. Thanks for the help everyone.
-Adam

Bacco:

You really need an Infra-Red Temperature gun. Very handy. You can "shoot" the various pieces of the cooling system and get a good idea about the status of each. I try to shoot the whole system (with the engine running) when I'm diagnosing:

- Raw water pump to ensure that it's cold and approx lake temperature
- Thermostat housing to get a feel for the temp where the thermostat is opening
- Intake manifold at the water passages to verify temps there
= Engine block in the area where the cooling jackets are to verify temps
- Exhaust risers

In my last boat (1994 SNOB) one spring, the temp gauge hit 200 and didn't drop below 180. I had a 160 degree thermostat with a new raw water impeller, so I was a bit puzzled. I went back to the truck and got my I-R temp gun. I shot all the cooling system components and everything looked OK. It turned out that I had a bad temp sending unit. Now, there is an I-R temp gun in the glove box of the new SNOB.

To answer your "heat sink" question....when the engine is at operating temperature and things are working properly, the heat produced by the internal combustion is dissipated by the cooling system in a balanced sort of way. If some component of the cooling system is NOT working, then that balance is thrown off. If you shut the engine off and let it sit a while (with no water flowing through the engine) the water that is remaining in the engine will rise in temperature above the thermostat set level. If you have a shower on the boat, you know what I'm talking about. When the engine is operating at idle, the shower temperature is perfect. Shut the boat off and let it sit for several minutes and then turn the shower on without waiting to purge the engine water first. Careful that you don't get scalded!

One option is to cap-off and/or remove the oil switch and temp switch. Just pay attention to the oil and temp gauges. The big red light is designed to get your attention so that you don't totally fry the engine. Again, in my old 1994 SNOB the big red light was disabled. When I removed the ProTec system, the oil pressure "switch" and temperature "switch" were useless as the ProTec ECM was removed. At first I left both switches in, but I later removed the switches and capped / plugged the holes.

JQ

It's not the temp sensor. That works as intended. I took it off and the light didn't go out, I ground it and it goes on.
It's the pressure sensor.
I have a few questions and one is TERRIFYING!!!!!
The top threaded part of the sensor moves like a plunger. I assume it is supposed to. I was excited that the oil leak was from the sensor and it was just ordering a new sensor and that's that. But here is the terrifying part. i took the sensor out of the block and the threads look fine. I put it back in (and didn't use teflon tape or sealant because it needs to ground (I am assuming).

When I started it back up oil pooled around the base of it. But I see no reason for it to be from the threads after putting them in, it went in correctly and felt like an NPT thread should, visual inspection showed no issue. If it's not coming from the sensor base is it coming from around the head gasket?????? Did the overheat when the acorn blocked the water inlet blow the head gasket?

The only other thing there is the intake manifold and I don't recall (nor would it make sense) that there are oil passages under there? Unless it also covered a section open to some area on the top of the block that has a seal like the distributor that is leaking. But even if it did there would be no pressure to force the oil out.

No blue smoke burning and don't see oil in the water from the exhaust.

What is the correct running temp? I'm running without a thermostat and run at 140.

Keno,
Thanks I'll check that out tomorrow in the light and figure out which is which. So there is no oil sensor feeding that light as well. Only the temp sensor?
The Carb conversion worked out well. This will be it's second season. I was wondering what that connection was on the fuel pump. So if the diagram rips it will pump the fuel out of that port, plumbed to the carb it will flood the motor and kill it? That's the idea?
Thanks Again!
Adam

My season is off to a bad start already, this is my blog post on it if you want a good man vs squirrel story.
Now Today!!! Just got a the big red "engine overheat or oil pressure loss" light on the dash. But... The temp gauge is reading 140 and the oil pressure is good.
I turned off the boat and let it totally cool down for a few hours. Started and it was fine, as soon as the temp gauge hit 140 the red light came on again again.
Ideas?

It just ruined a Saturday. Worst part is I had the kids spend 1.5 hrs cleaning the boat as a requirement before tubing. Then no tubing. Angry kids, wife, and boat owner.blog post

As a side note. There appear to be two temp sensors near the water pump? Is one for the light and one for the gauge?