Mar
17
I have 1986 Nissan Maxima and whenever I turn off the heater it immediately starts to overheat. What might be the problem and what kind of prices are we talking about to fix it?
Answer:
As others have suggested age of your vehicle and possible lack of regular upkeep has been your enemy. There’s a possibility your thermostat won’t open, but the fact putting your heater on helps indicates that the thermostat may be working (my understanding is that the heater often runs parallel with the radiator segment of the coolant system). But to check the thermostat you can check it by removing it from the engine and putting it in a pot of boiling water, it should open up, which means that it works correctly. Before i go into how to flush your radiator i recommend you also check your radiator to make sure that the fins aren’t too bent by stones, bugs & so on as well as not clogged up by mud, these two are real show stoppers & a significant cause of overheating, just like junked up internals on radiators. I would check coolant levels at the minimum, and would strongly recommend that you get the radiator flushed as well as the engine block. You can either get this done professionally, or could take a crack at it yourself. To get it done professionally, assuming there are no extra problems and the radiator doesn’t need to be taken out of the engine for it to be done would cost you under $70US. To do it yourself, you need to have access to take one of the top hoses off, as well as an alkaline radiator cleaner (note: be CAREFUL of what cleaner you get, especially if you have an aluminium block or radiator) mixed in correct proportions with fresh water as well as a hose and LOTS of fresh water. To do this properly, i flush the radiator out until there is no more rust or grime in the water and is just fresh water flowing through. Then i suggest you follow the instructions on the back of the bottle as they will tell you appropriate concentrations of the cleaner to use and how long to leave it in the engine for,and how long you should drive around with the cleaner in there. Oh and the reason why the heater being turned on helps stop it overheating is because the engine is so choked up due to the inefficient cooling that turning the heater on *just* gets the water cool enough to avoid overheating.