Ok about a two weeks ago my lower heater hose that goes to the block under the cylinder head split. I jury rigged it just to get it to the dealership and get new hose to replace it. I even went as far as measuring it out. Once installed I proceeded to flush the system to get all the left over coolant( was much left I just filled it with water to get me to the shop). I then filled the radiator with 50/50 premix, had a spill free funnel on there so I could let it get to operating tempature to make sure to bleed the air out(this is with the heater control valve to the heater core on full blast to get whatever air may have entered there as well) also replaced my thermostat and housing to block gasket. Now when I'm moving at highway speeds I run real cold. My fan will still kick on I can feel it. But when I'm at a stop the temp gauge will climb to where operating temp would be. I've bleed the system 6 times to make sure. Even cracked the bleeder valve next to the housing.. And now I'm at a complete loss. I don't want to replace the ECT if I don't hve to.

 

Sounds like the thermostat is probably stuck open if you are running colder than normal temps, but up to normal at a stop. Probably not much of an issue in the summer, but if you drive the car in the winter it would suck.

New thermostat is like 5 bucks, but it does mean opening the cooling system again, and doing another bleed.


Edit: somehow I missed the new thermostat part. Maybe it is in backwards, or jammed up with the gasket or some silicone or something, I would pull it and double check the direction and ensure it closes properly, and is the right temp, not a 160-180 degree thermostat.

 

I replaced it with new thermostat gasket an placed it in the same way it came out. I can check the temp. It's just wierd that all of a sudden after that hose split and dumped all the coolant that it starts doing it. When I bought the car made a 3 hour trip home with it and not a single problem.

 

You did bleed the coolant from the valve on top of the thermostat housing right? Not the rad cap ?

 

I'm not sure what he meant by "even cracked the bleeder valve" either. As in cracked it and drove around? Cuz that'd be unwise.

Also, I did want to mention that not all 4th gen thermostats are the same, apparently. The 96 one is different, as is the jdm bb4 one. I learned the hard way with my 96 lude with a jdm h22, had to go with 3 different ones until I discovered the issue. Just throwing that out there. I don't remember the specifics, I have it written down somewhere, but there was diameter and depth differences.

 

Ha no. As in I bleed the air out of the system with a funnel that screws on the radiator and ran it to operating temp. When air stopped bubblin from it I opened the bleeder valve and waited til coolant spouted from the bleeder. Tightened it down wih the funnel still hooked to the radiator to ensure that air didn't re-enter the system. Plugged the funnel and removed it. Replaced the cap. And then drove it home.

 

And no I matched the thermostat with the old one before I even removed the housing.

 

Correct

 

Possibly something got dislodged from inside a pipe or such when you did the flush and refill. I had a car doing this same thing, and when I went to replace the thermostat, there was a pebble stuck in the old one!!

 

I suppose that is possible. If I was to re-open the thermostat housing will the gasket on the themostat be able to be reused it was done two weeks ago. Probably more like three now. I really don't want to wait another week for another gasket lmao

 

The gasket will be fine, if u used rtv sealant just do your best to wipe it off before u reapply.

The other thing I can think of that is a simple measure is like snobordboy said, foreign object.

When I bleed the coolant, I keep a tray under the bleed screw and let the engine idle for 20min at OP temp with the screw open. Only after it bleeds a steady stream for 10min or more do I close it. Then I dump the excess back in the reservoir. Ps- it's fine to leave the cap off while u bleed, to make sure coolant is moving around. It doesn't suck air thru the top of the rad.

Best luck man

 

I didn't know that I just left the funnel on just to be sure. I've seen coolant pulse in the funnel before and as for the bleeder screw there was a steady stream. But I may have not left it open long enough. I'm still learning the Honda game haha. Thanks for all the suggestion guys I'll try it all on Monday and get back to yall

 

Yeah I always leave the screw open awhile. Especially after a flush, air pockets can be anywhere. It's nothing to leave it open and be sure.

As for fluid pulsing, that just means the thermostat hasn't opened up yet. Once its at op temp you will be able to see the fluid flying by.

 

I'll look into that too then. I think some one had already mention this. But just on clarification would it be possible tht my thermostat is stuck open? Because I didny have any pulsation of the coolant...
Thanks for the snowball effect haha.

 

The coolant never pulses? As in if u start the car after it's sat a bit it's already running?

Ur thermostat is stuck open and that's why ur not reaching optimum operating temp. When u start the car for the first time, does it take a long time to heat up?

I don't remember if u already replaced the thermostat, but just go ahead and do it.its super cheap

 

Yeah already replaced it. And I had to wait like a week for the gasket if tht goes around the thermostat to come in. Do you guys think I should just take y vin to a Honda dealer and get oem instead of getting the stant bull crap? Because I've been havin problems in my truck with stant thermostats..

 

If that's what you think you should do. I've had a thermostat get stuck closed. Blew a massive hole in the top of my radiator before taking the head gasket with it. So honestly if you don't trust the brand, get OEM.

I reread the thread, and I'm not sure where else to go here. A cooling system is incredibly basic. Did you measure the actual temperature?

 

Oh trust me I know it's basic. Lol it's a bunch of jackets a radiator a few hoses heater core ECT thermostat waterpump and cooling fan. I've built a 350 sbc in the pat but I don't remember what brand thermostat I used. And back to getting OEM, do you think they would be able to get an oem or equivalent for a 25 year old car? Lol

 

Honda still sells them genuine oem. They're like $25. A dollar for each year of the car lol

 

Well hell as far as I'm concerned car parts are just like tools(you get what you pay for). Though I'm startin to second guess that I put it in the right direction... If I didn't that's really embarrassing. I'll check it out tonight. If that doesn't work I need to go to Honda anyhow for a cv axle. Thanks for the help and I'll let you know what I'll end up doing

 

Sounds good. There's too many threads that never post a resolution. So if ya figure it out, post it.

Yknow now that I think about it I swear I've seen this problem before somewhere. Did u Google it?

And yes, the thermo springs face toward the block. Just in case