Inline 6 sat for years OVERHEATING

[redhoss02]

Truck sat for how knows how long before I got it. I removed valve cover dumped a gallon of oil over the valves and let it sit for a day. Removed the carb and rebuilt it and thanks to a member here got a filter and fitting to connect the fuel line. Cleaned build up in dist cap, installed new battery and she fired up. Problem is she would get hot really fast. I'm thinking since it sat for son long there is some build up in the water jackets that are not allowing the engine to cool as it should. As of now the gauges are not working till i figure out the wiring so I really don't know the temperature. Are there any tricks that can be done to help open up the water jackets? I have added a coolant flush additive to the water to try and help break everything up. Should I just keep doing that?

Replaced
water pump
thermostat
all hoses

[pimpston65]

Originally Posted by redhoss02

Truck sat for how knows how long before I got it. I removed valve cover dumped a gallon of oil over the valves and let it sit for a day. Removed the carb and rebuilt it and thanks to a member here got a filter and fitting to connect the fuel line. Cleaned build up in dist cap, installed new battery and she fired up. Problem is she would get hot really fast. I'm thinking since it sat for son long there is some build up in the water jackets that are not allowing the engine to cool as it should. As of now the gauges are not working till i figure out the wiring so I really don't know the temperature. Are there any tricks that can be done to help open up the water jackets? I have added a coolant flush additive to the water to try and help break everything up. Should I just keep doing that?

Replaced
water pump
thermostat
all hoses

you might have a vapor lock, the coolant might be getting trapped by an air pocket in the system!!! make sure you have coolant return if you put a gal in and drain it you get alot back out, if you get none back or vey little its trapped somewhere in the system.

[66Submarine]

Put a gauge in and see what the actual temp is; the inline sixes warm up to operating temp pretty quick IME.

Also, you could try just flowing water through it with a hose (take the thermostat out) and seeing if it doesn't want to flow.

It obviously shouldn't even flow water until the thermostat opens, though.

[crowdaddy]

Originally Posted by redhoss02

Truck sat for how knows how long before I got it. I removed valve cover dumped a gallon of oil over the valves and let it sit for a day. Removed the carb and rebuilt it and thanks to a member here got a filter and fitting to connect the fuel line. Cleaned build up in dist cap, installed new battery and she fired up. Problem is she would get hot really fast. I'm thinking since it sat for son long there is some build up in the water jackets that are not allowing the engine to cool as it should. As of now the gauges are not working till i figure out the wiring so I really don't know the temperature. Are there any tricks that can be done to help open up the water jackets? I have added a coolant flush additive to the water to try and help break everything up. Should I just keep doing that?

Replaced
water pump
thermostat
all hoses

I eventually had mine recored and it keeps it cool. Mine did what yours did, mine sat for 12 years or more, and would overheat, after I cleaned it, it did better, but it sprang a leak and the recore was necessary, either that or a new one.

[1963c-10]

Do you have gauges or warning lights? Two different routes to fix. Warning lights....check bulbs 1st, then sending unit. Gauges...check sending unit, then gauge....for wiring issues. Doesnt hurt to make sure you have good grounds on the engine & cab.

[1963c-10]

Make sure you have good water movement too...heater cores can be culprits when they've been sitting. At a minimum id pull the thermostat and lower hose and flush the block.

[jbon64]

i have a chevy 2 with a mid 70's 250. had the same problem , previous owner told me it had sat 3 years without running. when i drained the rad i noticed it had little flakes of rust that at times would plug up the drain in the radiator . i went to the extent of pulling the head off and power washing all the passages in both the block and head. after doing that my inline NEVER went over 180 degrees

[66Submarine]

Originally Posted by redhoss02

Problem is she would get hot really fast. I'm thinking since it sat for son long there is some build up in the water jackets that are not allowing the engine to cool as it should. As of now the gauges are not working till i figure out the wiring so I really don't know the temperature.

I'd be curious to know if it is actually overheating at all; he says he doesn't actually know what the temp is, and doesn't say why he thinks it's overheating.

Put a $20 mechanical gauge in it, run it, and see what the actual temp is before you potentially/probably do a bunch of stuff for nothing.

[1963c-10]

Flushing the block will not cost anything but a $1.50 gasket for the thermostat housing and disconnecting the two radiator hoses which takes 15 minutes at most. If it did sit for a long time.....I'd flush the block either way so as to not contaminate the other systems that the cooling runs through.

I also agree with getting a cheap temp gauge to see what temp your operating at. I wouldn't start an engine that's been sitting for an extended period of time that has old fluids in it to include oil, water and fuel. Just my $.02 worth....only takes a few minutes to flush any of the above systems and replace the fluids.

[jtrichard]

I took note of a few things there has only been one short mention about the radiator Have you checked the flow through it? could very well be pluged ....2 i agree with sub66 is it really getting hot? ...3 not to be a jerk is the stat in the right way? i have seen people put them in upside down....and the best way to clean the block is to pull the core plugs and pressure wash through them

[redhoss02]

Radiator has a small leak but is not plugged. I want to make sure everything is flushed before putting my new radiator in. As for the thermostat in know exactly what you mean and have seen it before. I'm working on getting the temp gauge working. That's another issue I'm having is the cluster wiring. Once these two are taken care of it's ready to be dropped and stickerd!

[TJ's Chevy]

Make sure you don't install the thermostat upside down.

[redhoss02]

Thermostat is installed correctly

[franken]

Good suggestions above.

Its overheating but you don't know the temp? What makes you think its hot?

Get a reliable/accurate temp gauge.
Good rad cap? How do you know?
Coolant?
Fan?
Shroud?
Sitting or driving?
Is the thermostat opening?
Reverse flush the big chunks out.
Get the heater working.
Coolant moving?

Might want to try some stuff and provide some info or this turns into a game of 200 questions and 500 bad suggestions with 5 good ones that no one listens to...

Usually the person with the problem takes the most difficult and most expensive solutions and starts with them. Sort of backwards.

[1963c-10]

Originally Posted by redhoss02

Thermostat is installed correctly

I'd still flush the system while you have the top end removed.