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hello just had a problem come up recently, d16y7 manual swapped by previous owner. idk what harness it has but my fan has always been wired to turn on with ignition. never had a problem until recently, my lower radiator hose is cold and my top is hot. i replaced thermostat twice and not sure what to do. my fan switch isn’t plugged in because it’s wired to be on all the time. i replaced the switch and hooked it up the right way and the fan never came on when it reached the right temp. idk if it’s the fan causing this but i don’t think my thermostat is opening. i replaced it twice tho so idk what to do. any suggestions?
Its Summertime, Pull the thermostat out, run it without the thermostat installed. (just to diagnose) It will take a long time for your engine to warm up, and possibly your heater inside the car will not ever get to operating temperature. But its summer, so you don't need your heater. This will help you diagnose if your system has a clog or some other debris. Also I've seen really bad water pumps, where the impeller blades were still turning, but they had no blade left on them. Thus the water pump being bad didn't circulate the water through the engine, therefore it would overheat.
Honda engines are kinda different when it comes to heat. I mean most 1.6L require a 1/2 gallon radiator, or 1 gallon in their entire system. They don't tend to need lots of cooling. As opposed to my truck which needs 5 gallons of coolant mix. Nearly every FSM that I've owned for a Honda, have all stated, to warm up your engine, start it cold, and hold the rpms at 3k rpm, for 3 minutes. Or until the radiator fans kick on twice. That is the signal that it is up to operating temperature.
To test your thermostat, you can take it back out, and put it into boiling water that you boiled in a (non cooking) pot on the stove. It has antifreeze on it, you don't want that in your food. Typically they open 170-180 °F, with some variants opening at 185-195 °F. Water boils at 212°F. So if you have a thermometer, and watch the temperature climb in the boiling water, with your thermostat in it, you can verify what temperature your thermostat is opening up at.
I'm not saying you did this, but I have also come across thermostats that had been installed backwards. Its been awhile since working on a D-series for me. I think its difficult to get backwards on a honda oem. The spring portion goes down inside the engine, with the flat part with center triangle pointing towards the radiator. I have worked on a Honda/Chevy (don't remember) that had one installed backwards, that was having cooling problems, until I swapped it around correctly.
NOTE: Running your car's engine, without a thermostat for along time is bad. Your engine oil will not reach proper operating temperature to burn off (evaporate) the moisture that naturally accumulates in the oil due to condensation. This suggestion is only to get your car on the road temporary, and to help diagnose where your problems is.
Its Summertime, Pull the thermostat out, run it without the thermostat installed. (just to diagnose) It will take a long time for your engine to warm up, and possibly your heater inside the car will not ever get to operating temperature. But its summer, so you don't need your heater. This will help you diagnose if your system has a clog or some other debris. Also I've seen really bad water pumps, where the impeller blades were still turning, but they had no blade left on them. Thus the water pump being bad didn't circulate the water through the engine, therefore it would overheat.
Honda engines are kinda different when it comes to heat. I mean most 1.6L require a 1/2 gallon radiator, or 1 gallon in their entire system. They don't tend to need lots of cooling. As opposed to my truck which needs 5 gallons of coolant mix. Nearly every FSM that I've owned for a Honda, have all stated, to warm up your engine, start it cold, and hold the rpms at 3k rpm, for 3 minutes. Or until the radiator fans kick on twice. That is the signal that it is up to operating temperature.
To test your thermostat, you can take it back out, and put it into boiling water that you boiled in a (non cooking) pot on the stove. It has antifreeze on it, you don't want that in your food. Typically they open 170-180 °F, with some variants opening at 185-195 °F. Water boils at 212°F. So if you have a thermometer, and watch the temperature climb in the boiling water, with your thermostat in it, you can verify what temperature your thermostat is opening up at.
I'm not saying you did this, but I have also come across thermostats that had been installed backwards. Its been awhile since working on a D-series for me. I think its difficult to get backwards on a honda oem. The spring portion goes down inside the engine, with the flat part with center triangle pointing towards the radiator. I have worked on a Honda/Chevy (don't remember) that had one installed backwards, that was having cooling problems, until I swapped it around correctly.
NOTE: Running your car's engine, without a thermostat for along time is bad. Your engine oil will not reach proper operating temperature to burn off (evaporate) the moisture that naturally accumulates in the oil due to condensation. This suggestion is only to get your car on the road temporary, and to help diagnose where your problems is.
my thermostat is installed correctly
how can i check my water pump?
I can't think of any reasonable way right now. other than pulling it out and replacing it, to check if its good.
To check if its bad. If coolant is dripping out from under it, through the weep hole, its bad. if you see coolant at the bottom of your plastic timing belt cover, behind the harmonic balance (crank pulley), its probably bad.
I can't remember if I could see the antifreeze moving in my civics when I ran them without the radiator caps on or not. I know that I've seen the coolant moving in other vehicles. With your engine cold. Remove the radiator cap. Start the engine, get it to temperature, and look (Probably need a flash light) to see if the antifreeze is moving in the radiator, or if its just stagnant. That is the only way I can think of to test the water flow from a water pump. someone else might have a better test. There is probably a way to pull one of the heater hoses to see if you have pressure. I wouldn't do that when the engine is hot though.
Is this your only problem, the top hose is hot, and the bottom hose is cold? Is the temperature gauge inside the car showing that its normal temperature? I believe that most engines pull in cooled water from the lower hose, and output hot water from the engine out the top, into the radiator to be cooled. With your fans on all the time, its possible that its cooling off the water by the time it gets to the bottom. How long is the car running for when you check this?
Is this your only problem, the top hose is hot, and the bottom hose is cold? Is the temperature gauge inside the car showing that its normal temperature? I believe that most engines pull in cooled water from the lower hose, and output hot water from the engine out the top, into the radiator to be cooled. With your fans on all the time, its possible that its cooling off the water by the time it gets to the bottom. How long is the car running for when you check this?
i was driving on the freeway and it randomly got hot, gauge went up to the middle but i let it cool down and checked, it pushed the coolant into the reservoir. i just did the head gasket because of this problem of exhaust gasses in the cooling system but no more signs of that, now i just have another issue with cooling. it sometimes boils after i turn the car off but not all the time , the car is very random
i just did the head gasket because of this problem of exhaust gasses in the cooling system but no more signs of that, now i just have another issue with cooling.
Was this the first time you've replaced a head gasket yourself? Were you able to check for warpage of the head and deck, while you had the head off? Is it possible that a dowel pin was placed in the wrong spot, or a rag or paper towel might have been left in a water jacket or coolant port between the head and block? Its very good that you were able see that it was overheating, and pulled to the side of the road before the temperature gauge went past halfway. Long ago, I was told , but never experienced, that if a Honda engine D/B gets hot enough to lose the head gasket, the head/block will be warped because they are aluminum. What never made sense to me, is that those mechanics also said even with decking and resurfacing the engine will always be prone to overheating. I hope this is not your problem. But I am going to bow out of helping you at this point, because I don't have the experience to help you, once you've been into the head gasket like that. Finding someone who has experience with that, or rebuilds engines would be a better source.
There is a test kit that you probably already know about, that you can buy from an Autoparts store, that checks to see if there is exhaust particles in the coolant. You might check to see if you new head gasket failed due to some reason.
There is a test kit that you probably already know about, that you can buy from an Autoparts store, that checks to see if there is exhaust particles in the coolant. You might check to see if you new head gasket failed due to some reason.
yes i’m sure of the head gasket being good now, head was decked and before i did the gasket i tried to bleed my coolant and it was just constant bubble and after it was all good, i just did a 5hr trip from vegas to cali and when i got back i noticed the cooling system starting to act up, head gasket is all good there’s not constant bubbling like before, and it’s not always overheating its either i’m getting shitty thermostats because i got them at autozone with warranty or im just getting bad luck with another part
Import direct aren't bad for aftermarket. I'm not sure what auto zone carries though.
check them on the stove before you install them, to make sure they work at the right temperature.
that will give you some peace of mind when you install them later.
04-28-2024, 04:02 PM
98 civic overheating
