Perkins 30 overheating

[William Thornton]

My Perkins 30 diesel is overheating after running for approx ten to fifteen minutes. At first, I thought is was the impellar and changed it out. The impellar was worn and split on three of the splines leading me to believe when under load, it would not push enough water through. It is still overheating and I do not know enough about them to fix it. Any ideas? Is there another pump I don't know about? Also, this appears to have a radiator on the side. Sorry to be stupid, but does the water run from the lake water through the radiator and then back out to the lake? My thinking was, that the radiator held coolant and water with the lake water cooling it and then being expelled with the coolant remaining in the radiator. The radiator is empty after I fill it with coolant, and I don't see it going into the bilge, for that matter I don't see it going into the lake either so I am befuddled. Thanks for your help.

 

[Les Andersen]

Purging Radiator

Bill,Certainly not an expert on Perkins but all the engines seem generally the same. Here goes. Think your larger problem is on the anti-freeze side (af) but check the freshwater (fw) side first. Check the oil and look for a milky color. Thats what antifreeze looks like in oil. If not there continue.Last time you ran the engine did you get water out your engine exhaust? If you did then assume that side is ok for now. If not, open the waterstrainer and ensure there is good flow coming into the strainer through the engine thru hole valve. Check the various sections of hose into the "radiator", out of the radiator, into the mixer elbow. Thats about as far as you can check. Just disconnect each section in turn and start it up for about 30 secs. You should have flow almost immediately. My bet is this is not the problem. If it is check/recheck impeller, pump, belt, hoses.On the af side. I would get a radiator tester from a service station and check that the radiator/system will hold pressure. If it does then the af fluid should be staying in the system. Start the engine up with a full radiator and cap removed. Wait for the internal thermostat to open and you should see the af level suddenly drop. Fill it back up immediately and keep doing this until the engine won't take any more. Sometimes it helps to lift the hoses to help remove trapped air but be careful you don't force hot af out of the open radiator. Until you get all the air out of the system the engine will not have sufficient af to cool properly. You have to ensure the water heater, all hoses, engine internal chambers, radiator are all full. Also ensure there is af in expansion tank and that all hoses are in good shape. Sounds like someone drained the system and never refilled. Other problems might be engine head gasket, internal af pump, thermostat, crack in radiator. All this and more should be in your engine handbook. Check online and get one before you try anything drastic.Good luck,Less/v Mutual Fun