Questionok pulle radiator, not too hard to do, it was full of antifreeze, again not water like i kept putting in, now on the radiator there are cooling lines for the transmission, howere on the other side of the radiator(drivers) there are 2 of the same holes and ythey arent blocked off normal? now that i have the radiator out whats the next step i can take, i am not a repair shop so i dont have access to all the test materials like they do. whats next?. thank you-------------------------
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ok i checked the fans come on at 230 degrees,found out i need a heater core. it was bypassed,took the housing where the thermostat goes off and found NO t-stat,could this be the problem? i was told that this car has a 2 stage t-stat(whatever that means,i also noticed that antifreeze was in the radiator but as i was testing the car i only put in water i did this like 3 times why is there antifreeze in the car when i only used water i hope this is making sence to you...thanks-------------------------
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thanks i was just worried the block was clogged but from what i understand the northstar almost never has that problem, would i be able to drive the car say 200 miles? i understand that it shuts down 4 cylinders to keep cool or would that be a big mistake to drive it...thanks again-------------------------
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hi, i just bought a 94 eldorado with the northstar motor, i havent checked it out yet but the old owner said it over heats. i let the car run for about 10 min and it jumpped to 230 degrees without the cooling fans comming on, i also didnt feel any coolant flow in the fill container,he said it needed a water pump but it looks new(clean and fresh permatex )i know alot about cars but nothing abou the northstar motor. i am hoping its a t-stat but i dont know.any ideas? where should i look.thanks
tony
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Hi Tony, The fist thing to do is make sure the coolant bottle is up to the full mark. Add as necessary. Most engines use a seperate coolant sensor for the cooling fans and the dash gage. You need to determine what the actual coolant temperature is and if the sensors are reading correctly. I use an infrared thermometer with a red LED so I know where the temp is taken from. Sears sells them pretty cheap. Changing the thermostat is a good first choice for any engine that is overheating especially if the upper rad hose doesn't feel hot while the gage or light says hot. I had a couple of cars where the temp sender went bad and showed the engine was overheating and the fan never came on because in actuality the temp was only 210 degrees when the dash gage read 260. If those suggestions don't help then inspecting the waterpump is pretty easy in that the back cover comes off and then the impeller can be seen and turned. Make sure the impeller hasn't rusted away and it can't move on the shaft. To change the pump requires a special socket that an auto parts store might have in their loaner tools program. To remove turn it clockwise with a long breaker bar. Sometimes they don't want to turn and extra effort must be exerted to the point you'd think it would break and then it turns. Hope that helps. Bill
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Hi Tony, The way I remember it is that GM testing drove their engine at least 1000 miles without any antifreeze in the engine and didn't have any problems. By turning off the fuel at the injector it allows only air to enter the cylinder to help cool things down. The computor will switch pairs of cylinders and if hot enough will turn off up to 4 fuel injectors at a time to help cool things off so you aren't left stranded somewhere. I was working on a car once that was overheating and at idle the engine died because rpms weren't high enough but driving shouldn't be a problem. Make sure that that there is antifreeze in the bottle and driving 200 miles shouldn't hurt the engine if the computor is working properly. Bill
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Hi Tony , The fact that there isn't a thermostat is kinda interesting. Whether it is a 2 stage I am not sure but start by installing a new thermostat because the engine will run its best with one installed and make sure to use the one that is called for...195 degrees I believe...instaead of higher or lower that way you can evaluate how it runs. The fact that you added water to the overflow bottle isn't too big a deal because it won't freeze at night. Unless you get to the point that the coolant tester says +20 degrees then the engine might not be able to cool propperly. Just looking at the color is real tough to tell the strength of the solution and if it starts out dark green then you will need to add alot of water to change the color noticably. Try the stat and heater core and see how the cooling fans do for overheating. Then once you have that working and are sure the aren't any leaks then you can flush and fill the coolant system and add the sealtabs. Bill
AnswerHi Tony, Take the rad to a radiator shop and have it flow tested. There could be an internal restriction inside that isn't allowing the antifreeze to move through fast enough. The 2 uncovered holes are for an optional engine oil cooler and some northstar engines just use a tube that loops the oil back into the engine by the oil filter instead of going through the rad. Bill
