92lxsleeper

well i just finished replacing the headgasket in my 92 dx. head was within spec so i didn't have it milled. after warming the car up, it was smoking white bad, but stopped after a few miles of driving. but when i got home, the top radiator hose was hot, but the bottom was cold. heat was blowing mad hot.

im thinking that the thermostat is stuck closed.

safe to assum this bet? and will it hurt to drive short distances in this car? 5 miles and less.

sle418

Yeah i think it was probably the thermostat. cheap and easy to do!

obuhmyuh

it could be the thermostat, that's the first place id look considering its a $9 part, and good to change every so often

92lxsleeper

Ok I just replaced the thermostat this morning and its a no go. The bottom hose still is ice cold even when the heat is blowing so hot I have to roll down the windows. I'm gonna replace the waterpump tomorrow on thanksgiving now. Oh joy. If the waterpump doesn't solve it, what else can it be? All of the following parts are brand new with only 5 miles on them:

Radiator
Both hoses
Thermostat
Headgasket

If the waterpump does solve it... what else can it be? The block can't be clogged cause the heater still works. But I'm gonna flush it out when I do the water pump anyway.

Abius

For personal reference, how would one check if the block is clogged, because I am in the same boat. I changed the waterpump but it was still over heating, and now Im in the process of doing the headgasket, thermostat, fan switch.

So how does on check, and can one check with the head off?

Thanks
Matt

92lxsleeper

im gonna take the thermostat out, shove a hose down the upper hose inlet and turn the hose on and see if water shoots out the thermostat housing.

however i'm not overheating, my gauge only goes up maybe 1/4 of the way while driving.

Abius

Can this be done with the head off, or does it need to be on?

Nvm I guess I need the head on, since it goes into the head lol.

What would be the next step if there is a clog?

KangBanger

Have you check to see if the plug right next to your thermostat is plugged in all the way?

Also, it could be that you are not letting the car warm up enough for the thermostat to finally open up.

92lxsleeper

i let the car idle for 30 mins and nothing happened. fan didn't even come on, probably because without the thermostat opening, the coolant cant heat up the fan switch (on the thermo housing).

tomorrow im doing a timing belt and waterpump job, and im gonna flush the engine completly. idk how a waterpump can fail. but idk.

DAintegraGSR

i just bought a 94 eg that was doing the same this. replaced rad, a leaky hose and the thermostat.still had the same issue. Car would warm up top hose would get hot bottom hose cold and the fan would not come on.
pulled out the water pump the were no "blades" left on the prapeler. replaced the water pump, problem solved

92lxsleeper

nice. but where did the blades go? lol

i just tested my stock thermostat. i work at a restaurant so i brought home a nice thermometer and i boiled some water and the thermostat did not open until 208 Fahrenheit. now i know thats not right cause its the factory 78 celcius thermostat. and 78 degrees celcius is about 172 fereheight. so it defiently wasn't functioning properly

Matt93eg

They seem to melt. Years ago I had a buddy tell me that one of his friends civics was overheating and that he had already replaced Thermostat, Rad Hoses, Radiator and it still overheated. So we tore it down to find all the blades on the impellar GONE. The coolant he said that he first drained out was just nasty and orange with rust. So I figure corrosion slowly ate away at the impellar. After that the car ran great.

DAintegraGSR

lol thats a good ? had me stumped as well once i pulled out the old pump an seen wat was goin on.
I was able to pull one blade from the cooling chamber. The others im assuming ran through the coolant tube on the back of the motor and got hung up behind the thermostat and were flushed out when the thermostat was removed. the guy before me had been running it with out one trying to diagnose the cooling issue.
but your thermostat aint opening untill 208 oF that sounds like your problem

itsnotfast

They are metal blades, they dont melt lol. After time the blades will wear down from trying to move liquid. Using water as opposed to antifreeze will speed this process up alot due to the rusting and minerals in the water.

Another thing, when your coolant starts looking rusty thats a good sign that you should probably change the waterpump as well as flush the system.

92lxsleeper

well i did a full coolant flush today while doing the waterpump. and after putting everything back together, the thermostat seems to be working now. the bottom hose started getting slightly warm after a while of driving.

now... i dont think the waterpump had anything to do with it. cause the old waterpump looked to be in pretty good shape. however, i think maybe i had too much coolant in the system, and not enough water. and that could not heat up enough to open the thermostat. or carry enough heat away from teh sleeves the open the thermostat, while the engine block is really overheating.

Abius

Ya, I did the same thing, I went to go change the water pump, and it was still in good shape. I also came to belive that it might have been improper mixing water to prestone that could cause it. But I was still taking prestone so I went ahead and did the head gasket.

92lxsleeper

well its been almost a full month, and the rad is staying full and the overflow isn't loosing any coolant so i say the car is fixed. however tons of water still comes out the tail pipe lol. there was a long frozen stream down my driveway yesterday before the snow came.