ok when my Brother bought his mav it was overheating and so we replaced the thermostat with a cooler one and replaced the water pump. It supposedly had just gotten a new radiator when he bought it. It is however still overheating. Where should i look now? BTW it has no fan shroud and i noticed that the last guy painted the radiator all black even the fins with basic home spray paint(still tacky), whould that cause a problem? Oh and the heater works fine so is it safe to assume that means the core is not the problem? 77 mav 200 formerly 302 -Jeff
You dont say how hot it is getting. At this point I would suspect the radiator, I never believe people when I buy a used car and they tell me what is new. Especially when you have tacky paint. Pull the radiator and take it to a radiator shop and have it tested. Dan
What Dan said. Dont try just flushing it out because putting a hose in the top and disconnecting the bottom radiator hose, then running a garden hose in it wont tell you squat. It only takes about 4 or 5 of those little tubes to be open to pass as much water as a 3/4" water hose running full bore. Sometimes you can tell if the radiator is plugged up by starting a cold engine and as it heats up, feel the front of the radiator at various spots. if there are major temperature differentials, its probably plugged.
With those temps,, yeah you have a problem. I havent had a radiator checked in many years, cant advise you there. I just usually buy a new radiator, in the long run, usually the best bet. But since you really dont know what the problem is yet, get it tested. Ask the shop first, I would imagine it could be done for under $35.00? Dan
Jeff did you check the coolant circulation to make sure that the thermostat is opening and water pump is pumping after they was install? I have obtain new items that was no good and took it back and got other new one and it work fine. If the coolant circulation is working then that radiator would be next on the list. Good luck
Put it in a pan of water and put it on the stove. If you have a thermometer (the wife usually has some kind of cooking one) see when it opens. If you dont have a thermometer, water boils at 212 degrees so it should open well before the water boils.
ah ah muy bueno. and i guess i could just start it with hoses off and see if it shoots water to check the pump?
a cheap thing to try is to check the radiator cap. they can pressure check it and if no one has the tool, just buy a new one. if it won't hold the pressure it will overheat easily.
Jeff in order to check one both must be working like for example. You can let the motor sit and run which is kinda hard in the pocket or you can take it down road on a quick trip and back so that the motor can almost reach operating temp. Now with the motor still running get a thick rag to make sure that if your water system is pressurize that you don’t get burn and take the radiator cap off. Now lets say that your thermostat is a 170 degree stat, when the motor reaches near or a lil past this temp and so on for any other different degree stat. it will open, this will let the pressure from the pump to flow the coolant. Now with the cap still off, just watch the coolant in the radiator and if you see it flowing then both items should be working. I hope this help. PS: If the stat is close the water pump cannot flow and if the water pump not pumping the open stat will just stay open, showing no flow when u take the cap off.
I had all kinds of overheating problems, and the only cure was a shroud. Tried electric fan, cooler stat, but the shroud was the key.
Is it a 6 or v-8? has water pump been replaced? Maybe someone put reverse rotation pump on??? Be sure system holds at least 16lbs pressure.I think Auto-zone has a loaner tester aval.Are the hoses new,sometimes they collapse from the inside.Do leak down test on cyl.s to rule out head gasket.What is the overall running condition of eng.? How much space is between fan and radiator? A fan shroud would help. These are just a few other things to look at in addition to what others have suggested.Good luck and keep us posted on what you find.
