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CS280 running hot

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briang0

Regular Contributor
"Hi again. I fixed my fuel is

"Hi again. I fixed my fuel issue now another problem. I'm beginning to think I'll never get to go fishing. This is a recent problem within the last 3 days. I went out for a cruise and as we went I watch the engine temp continully rise. Very unusual I use to have a hard time getting the motor to a decent running temp. The temp kept creeping by the time I got back "after about 20 minutes it as almost 220 degrees. I let her cool down and checked the thermostat, doesn't have one. Pulled raw water pump impella looks new. Made sure anti freeze was full. Let her idle for about 10 and temp started to rise.
The temp will not go down once the engine starts to heat up. I'm looking for some troubleshooting ideas. I looked into the heat exchanger while the engine was running and the flow appeared good. If it was a car I'd be looking at the radiator which makes me supsious of the exchanger. I don't know how old it is. Does anyone have any ideas on where to look.

Thanks,"
 
Here is an update. When I fee

Here is an update. When I feel the raw water pipe going into the heat exchanger it is cold. The heat exchanger is very warm and the water coming out going towards the exhaust is hot. I'm not sure if this is normal or not. Can I flush out the heat exchanger with a garden hose? Can I do the same with each manifold ? I'm going stop at the store and pick up a laser temperature probe and try to get some numbers. I have a ball valve on my raw water inlet. There is about 18" of hose on it. I notice that if I open the valve when the hose is disconnect from the pump I expect water to come in but it didn't not sure if this is right. This is new territory for me just trying to figure out stuff.
 
"Several things.
1) You s

"Several things.
1) You should have a thermostat installed to keep block cooling properly (install factory recommended temp unit, may be a 160 deg)
2) Raw water pump belt may be slipping while under a load causing lack of proper water flow, check belt tension.
3) Water pump suction line (the large return from heat exchanger) may be failing and during high flow is collapsing and not allowing water flow of coolant through the system
4) Air in system (fresh water side) bleed air from top of thermostat housing.
5) Oil cooler is pluged up not allowing flow to heat exchanger.

Note: The raw water line will only let water come in to the boats water line level, so you would need to check with hose off of ball valve to verify water free flows through valve / suction screen.

Just a few items to consider."
 
I checked the hoses and they l

I checked the hoses and they look good I did adjust the belt on the fresh water pump it was a little loose. I started the engine and it heated up pretty fast. I put my laser thermometer on the exhaust manifolds and the starboard one was running around 135 f the port one was running around 210f I figured there is a blockage in there somewhere. I removed it actually it wasn't too bad broke one bolt but it left me a piece to grab onto so I got it out. I decided that it would be better to replace them in a pair since I have no clue how old they are so I removed the starboard one too. I broke 2 bolts on that side but I have about a 1/2 inch sticking out so I'm hoping that they will come out without too much fuss. I started soaking them tonight and I plan on trying tomorrow night if the weather holds up. Other then grabbing them with a pair of vice grips does anyone have an idea on another way to get them out? Thanks for you help Robert. Now I have to locate the exhaust manifolds and elbows it's a 1964 Crusader CS280 Chevy 409 I'm open for suggestions on that too. A thermostat and gasket would help too.
 
"Removing seized bolts are no

"Removing seized bolts are no fun, you may need to add fast heat around the manifold / bolt area and quickly try removing the stud before it expands from the heat. You can try talking to the guys @ EBasic Power on getting parts http://bpi.ebasicpower.com
With an engine system that old I would recommend replacing the raw water pump and inspecting the oil cooler and heat exchanger and possibly have them serviced (tanked cleaned) Your raw water and fresh water system must be flowing properly i.e. pumps working properly and hoses not defective (on the inside from age) especially the water pump suction hose from the heat exchanger. The raw water system should keep the riser & elbows cool if you have proper flow. The engine manifolds will run hot, but not as hot as your running. When you removed the risers / elbows did you find plugged fittings and passages? if so then you may have found part of your problem. The raw water pump impellor should be replaced every year or so depending on the hours used!"
 
"Thanks guys I'm having id

"Thanks guys I'm having identical problem with my port engine. I did the t-stat and the raw water impeller(was like brand new) last night. I quess the next thing is to check the hose's and fitting's and flush the heat exchanger. The only difference with mine is that while running, the temp stay's between 160 and 180. When I go down to idle speed the temp skyrockets to 220 and slowly and I mean slowly comes down to 180."
 
Here's an update I flushed

Here's an update I flushed and cleaned both manifolds reinstalled and now here is what I have. The engine will idle all day and run right around 160 the manifolds run right around 125 to 130F. If I go for a cruise she will slowly creep up it takes about 35 - 40 minutes running around 2000 - 2500 rpms. If I get on it and push the rpms to 3000 she will heat up faster. If I drop the rpm down to around 1500 she will cool down within 10 minutes. I checked the raw water pump and the impella looks new. The flow in the heat exchanger look good. I have checked all the hoses and connections and haven't found anything that looked like a problem. I have taken the ends off the heat exchanger and cleaned out some seaweed and then ran a wire through each tube. I'm not quite sure where to look or if I'm wasting my time and my old exhaust manifold are the cause. I have not been able to find a set yet so I'm hoping to at least finish the season with what I have. Any ideas????
 
"Well I think I have found the

"Well I think I have found the problem, tonight I started her up and watched the hoses when I brought up the RPM's to about 2500 I notice that the main hose going from the fresh water pump to the heat exchanger only on the end closest to the pump began to come together. I got a good look at the hose and there are 2 hoses joined together one has like a metal spring in it the other is preformed this one was failing. I'll let you know tomorrow night if it works when I rplace it."
 
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