hot-cold-hot-cold-hot-cold

[jlaccord89lxi]

I was having a heat problem a few months ago (actually a over-heating problem) and i had to replace the rad. So, $250 CDN later, i have a nice shiney rad in my engine bay and I'm hopeing that my problem is fixed. That was about 6 weeks ago, and now in the last week, if i am driving around town, once my heat guage goes above half way, it stays up there, lingering between "H" and the middle of the gauge until i shut it off and let it rest. I drove from work, to downtown (15...20 mins tops), and yes, i was idleing in traffic quite a few times, but even so, there's no way my engine should be getting that hot (all the way to "H"). It does eventually cool down and the needle will drop, but only after its been up there for a good minute and a half or so, or if i start to drive (the rad fan and the AC fan both work and they do turn on so its not the fans). My question is, WHAT COULD IT BE??? I'm thinking the water pump is not working properly, or the thermostat is sticking, or one of those temp. sensors is broke (on top of the thermostat housing). OR IS THERE SOMETHING ELSE??? Any help would be appreciated. ~Sting~

[AZmike]

Try replacing the thermostat and seal. Your water pump is still spinning so unless it's got a whole lot of gunk in it, it's still pumping fine.

[Dutchboy]

whens the last time the thermostat was replaced???

if you dont take out the thermostat when you do a rad flush you might as well not flush it becasue the junk will build up right by it and contaminate the new fluid.....

thermostats can stick...open...or closed...or open sometimes and get shut closed again...
had this happen to a peice of equiptment at work...I had to wack the fricken thermostat husing with a heavy object to get it to open ,,,,,

Actually is the car actually boiling or very hot under the hood????
otherwise it may be the sensor....

Ben

[shepherd79]

i would say thermostat. it is cheap to replace it and you can see if it was the problem.

[jlaccord89lxi]

thanks for the fast replies... i will go buy a thermostat on friday and put it in there. Should i flush the rad again though?
DutchBoy:...it doesn't feel as hot as it did before i got the new rad, so that did quite a bit, and if a new thermostat doesn't do the trick, i have 2 spare engines to grab the temp. sensors from.

[Dutchboy]

If the engine doesnt feel too hot it may be the sensor/...

but it also could be the thermostat still....it may open and close intermitantly....
the best bet is to change it and flush the whole system out...

when you got the thermo out ...flush out the head with a hose and shove it in the head a bit....keep flushing the engine and alternatly ..the rad until all the water coming out is clear...then install all the peices and fill her up....

When i flush it i keep the drain open on the rad and keep the hose going enough to replenish it while the engine is running...
.

Im not sure were the switch for the fan is but does anyone know if it turns on by the same guage in the dash or another sensor?????

it seems like the fans work so at least it shouldnt overheat..
Ben

[hondaisthebest]

Hey guys does somebody was able to put there hand on the valve covers when its hot???
Because the covers get so hot dont if its a lack of cooling or everybody are in the same situation????

[A20A1]

Don't forget about the 17mm bolt to the left of the header... it drains the block. and make sure you bleed the system again.

[smufguy]

also, get a 50 coolent 50 water type coolent after u flush your system with water, cause no way ur gonna get all the water from ur system after flushing and also the 50-50 coolent might be effective in cooling than the reg coolent.

[jlaccord89lxi]

thanks for all your help. I'm going to do this this weekend. Just a few thoughts though. Wouldn't it be harmful to use a hose to spray into the engine? Mines EFI (which probably doesn't matter) but it seems to me like it could damage something.
- when you buy a thermostat, does it come with a new seal?
- where is this 17mm bolt to drain the head of coolant and is it neccessarry to drain this if you hose out the head?
- should i drain the coolant reservoir? How?
This will be the first time i do anything like this to my engine all by myself, so i really don't want to screw up and have to ask for help so is there anything that has to be done that could easily be overlooked? I don't want to end up doing more bad than good.

[dj99]

You will get a good flush with a hose stuck into the thermostat hole. It will not hurt anything. Just make sure to turn your heater control to high in the car first, open the block & radiator drains. Hose out the top hose too. It really helps to remove the bottom hose from the radiator for a good flush.

You have to get a new gasket when you replace the thermostat.

The 17mm block drain is accessed from under the car, behind the exhaust manifold. It isn't very easy to reach, and don't lose the washer.

You can remove the coolant reservoir by removing the hoses first, then pulling it straight up out of the body bracket. It is a good idea, because it gets a lot of grunk in it.

It's no fun, but it's worth it.

[jlaccord89lxi]

ok, sounds like a easy job as long as i have the patience. One last question though, when you said"...make sure to turn your heater control to high in the car first...", i understand this part, but do you mean i should have the engine running while i hose into the head?

[dj99]

No, just so that the heater core is opened while you're flushing everything. You can see the heater hose opening just inside the thermostat housing. Make sure to get some water through there.