This is not ford, but has been irritating me. I have an 80s ingersoll-rand towable air compressor that i recently bought for sandblasting. It has a 4 cylinder hercules. It runs hot no matter what I do. I have had the radiator boiled out, taken the thermostat out, started it with no hose on top to check the water pump (which works fine) and changed the temp gauge. What could the problem be? It will idle at 200 but when I press the "service air" for pressure it goes to 240. The only thing I have not done to it is advance the timing. I am lost.

 

I'm not much on gasoline engines, but a couple of things come to mind. Check the air cleaner for restriction and also the exhaust. Some engines have a heat riser on the exhaust manifold and if it is stuck closed will cause an overheat problem. If the carb is dirty and running lean, this can also cause it.

 

Portable Air compressors have two radiators, one for the engine coolant and another right in front of it for the compressor oil cooler. Very often, especially in sandblast operations, dirt and debris get caught in between the two and block the airflow from the fan. only remedy is to separate the two and pressure wash them separately. You cannot wash them while they are together because the velocity of the water (pressure washer water) is not sufficient to push the debris through both cores.

You can test this by holding a bright light on one side of the coolers and looking from the other side to see if you can see the light.

If this doesn't cure it then I'm thinking blown head gasket in the engine. You should be able to test for this with a "Block Test Kit". Available at most auto parts houses. You need to drain some coolant out, remove radiator cap and (using the supplied tool) draw a sample of the air above the coolant in the engine radiator and if combustion gasses are present then the blue chemical in the test kit will turn yellow. This must be done while the engine is running under load.

One more thing, are you sure you are reading the engine temperature gauge? If by chance the compressor oil is overheating then I would suspect a bad oil temp thermostat. Also the compressor oil cooler is mounted in front of the engine radiator and if the compressor is overheating then the cooling air blowing through the oil cooler will be hotter than normal by the time it gets to the engine radiator preventing heat loss in the radiator. Does that make sense?

Good luck and let me know what you find.

 

When I had the radiator out, i washed the oil cooler. Also when I bought the compressor the crankcase was full of water (not antifreeze) At first I figured it was the head gasket so I pulled the head. I was not, so i installed a new one and after 2 hours of running with the new gasket. I figured someone had poured water in it at the auction hoping to scare everybody away from it. I re torqued the head bolts, So a dirty oil cooler and head gasket is out of the question. And it is the engine temp gauge, because I changed it. It has 4 warning lights that tell you when there are problems and the "engine high temperature" is what comes on at about 240.

 

i found out how to reply to a post... but i dont see where i can start a post.. any help... thanks... sorry.. this starts to kinda happen after you turn 47
thanks guys..

 

Go to where you can see all the threads - posts- and there is a place to click that says "start new thread"

 

radiator need a clean?

sam

 

i had a engine that over heated in a worlthing air compressor put a oscope on it found fire on one cylinder was way off pulled dizzy and found lower bushing was shot real bad. took to machine shop and had bored and bushed. the exhaust would run red before ran fine after. might want to look at bushings

 

What pressure is the compressor control set at? Is it perhaps set too high?

 

I had it boiled out. It runs about 100 before it idles down, but When I am blasting it runs about 80.

 

Only thing left to check is the block check thing or the compressor thermostat.

 

Explain to me what the compressor thermostat is.

 

First off remember we are talking about a rotary air compressor where the oil is injected into the air compressor for sealing, cooling and lubricating. it gets mixed intimately with the air and is removed from the air stream through a seperator before it goes out for use. The injected oil must be at 160° for efficient operation. The compression raises the oil temperature 30° if the compressor is in good shape. This hot oil is then piped to an oil cooler where it is cooled down to near ambient. Now the oil is much too cool to be injected into the compressor so we have an "oil mixing valve" to mix the cold oil and hot oil to provide the 160° desired injecting oil to the air compressor. We normally call the mixing valve a thermostat so everyone will know what we are talking about.

The mixing valve is probably located down low in the frame in the piping leading up to the oil cooler.

Now you probably know more than you ever wanted to know about air compression theory.

 

This is a generic question, since I really don't know anything about these particular compressors...

Is the right fan/shroud installed? Maybe it isn't pulling enough air across the two heat exchangers to cool the liquids properly when under a load.

Dave

 

I understand the oil thermostat, but i checked the temp on the compressor and it runs from 172-180, so that seems okay, and it has the factory fan shroud and it pushes the air out, instead of in. It is still running hot, i used it yesterday. All i got done was wait for it to cool down.