I3ooS710

As I was driving home last night, I noticed my temperature gauge rising. I was going approx. 70-75 MPH at a constant speed in a free flow traffic condition. It went up about 3/4 of the way to "HOT" so I turned on the heater full power at the warmest temperature possible. However, I felt very little to no heat whatsoever.

The needle kept rising and as it got hotter, it would suddenly jump down to what would seem like normal operating temperature; a little below 1/2 way.

It was raining last night so it was too late to do anything.

This morning, I bought a new radiator cap, coolant, and a new thermostat/thermostat gasket.

I proceeded to change everything, filled it up, let it warm up and everything seems fine. Temperature was normal, and the fan DOES work.

As I started to go on the freeway (3-5 min into my drive), the needle started raising again. As I kept driving, I turned on the heater again. Once again, cold air, not hot.

I decided to turn around to head back home to bleed the system. Sure enough, there was plenty of air.

Refilled what coolant I had lost and drove it around. Still it did the same thing. I checked my oil and no signs of milky residue or water.

What could be causing this problem? Is it possible that it's the radiator? maybe the hoses? WHY is the heater not getting hot?

I hope someone can help me. Thanks!

BTW, I just remembered that I saw drops of coolant that would SLOWLY drip from what I believe is the heater valve. (w/ the cable connected to it from inside the cabin)

nutball72

i had to change my hoses and make sure you get new hose clamps because the old ones are wack

O RLY

I just had the same problem. I bought a new Fluidyne, but that was only part of the problem. Even though you fill your radiator up completely, you need to start the car and let it circulate. Then add more water, let it run, add more water, and so on. Just keep adding water until you can't possibly add anymore. 95% of the time its just that you 'think' you have enough water in the system, but there's really not. I know it sounds to dumb and easy to be true, but try it.

fmrprojects

you can have a bad heater core. how many miles is on the motor. maybe the water pump is bad and its not circulating coolant through the cooling system. best way to fill up the coolant is to fill it to the top, let it warm up, turn on the heter to its max(ventin not circulating), and top off the coolant

Gadget

You say you lost coolant.. The problem just spurratically happened when you were driving home.. Hmm..

Is your coolant level always low after you notice it getting hot?

What's the level of coolant in your overflow? is it normal where it should be or is it overfull?

Honda B and D series engines are an "Open deck" design.. if you blow a head gasket on these engines 80-90% of the time you will never have milky oil.. compression from the power stroke will bleed through the gasket where it failed into the water jacket over pressurizing it and forcing coolant out the radiator cap into the overflow can.. That's typically the largest tell tale sign of a blown head gasket in a honda.. The leaky heater valve is more than likely a result of this increase of pressure in the coolant system due to the blown gasket..

refill the coolant system, drain the overflow can to the normal level and drive around the block a few times or until you notice it getting warmer than normal.. Stop and check the level on the overflow.. if it's higher than where you filled it (Probably almost overfull now) then start pulling the head off to change the head gasket..

postman

sounds like heater core going bad

ROOROWNS

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Gadget &raquo;</TD></TR><TR><TD CLASS="quote">

refill the coolant system, drain the overflow can to the normal level and drive around the block a few times or until you notice it getting warmer than normal.. Stop and check the level on the overflow.. if it's higher than where you filled it (Probably almost overfull now) then start pulling the head off to change the head gasket.. </TD></TR></TABLE>


That is what you need to do, I think you'd find your problem
Sounds like a headgasket or water Pump. Start experimenting with certain things andyou can anrrow down your search for the problem.

I3ooS710

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Gadget &raquo;</TD></TR><TR><TD CLASS="quote">You say you lost coolant.. The problem just spurratically happened when you were driving home.. Hmm..

Is your coolant level always low after you notice it getting hot?

What's the level of coolant in your overflow? is it normal where it should be or is it overfull?

Honda B and D series engines are an "Open deck" design.. if you blow a head gasket on these engines 80-90% of the time you will never have milky oil.. compression from the power stroke will bleed through the gasket where it failed into the water jacket over pressurizing it and forcing coolant out the radiator cap into the overflow can.. That's typically the largest tell tale sign of a blown head gasket in a honda.. The leaky heater valve is more than likely a result of this increase of pressure in the coolant system due to the blown gasket..

refill the coolant system, drain the overflow can to the normal level and drive around the block a few times or until you notice it getting warmer than normal.. Stop and check the level on the overflow.. if it's higher than where you filled it (Probably almost overfull now) then start pulling the head off to change the head gasket.. </TD></TR></TABLE>

Although you bring up an interesting point about the headgasket, I highly doubt it is. I replaced my headgasket, waterpump and timing belt about 3k miles ago. I NEVER drive the car hard. Also, there's no sign of white smoke anywhere so I believe the head gasket is still in great shape (OEM Honda gasket). I keep my eyes on my overflow tank, and it is where it always is. Nothing has changed.

If coolant doesn't pass the heater valve, could that cause the motor to overheat? As I stated, the heat does not get hot after I noticed the engine overheating. I'm really struggling to find out the answer.

As far as coolant levels go, I'm aware that a majority of time, people often think that it's full. I've made SURE that the coolant is up to level and is full.

I3ooS710

UPDATE

I bypassed the heater valve/core but it still overheats.

NEW INFO:

I parked and touched the lower radiator hose and it was cold as if no coolant was passing through it. I touched the top hose and it was unusually hot.

what doesn't make sense is I just changed the thermostat..

I3ooS710

ttt

Slopoke

the lower radiator hose was still cold while it was overheating? If so, make sure you got the correct thermostat, or that you installed it correctly.

One thing you can do is just pull the thermostat out temorarily and then drive it around and see if it overheats.
If it doesnt, then you know the therm was the problem.

If it does, then your probably looking at replacing the radiator.

O RLY

The heater core has nothing to do with it overheating. Nothing. And as for the water pump, its not broken or else it would lock up and break your timing belt. Unless the propellor is spinning intermittently, which I doubt. Just fix any and all leaks, flush the system, and fill it up, making sure you run the car while filling the rad and reservoir. That'll fix it, you'll see.

I3ooS710

I let the car sit in idle for abotu 10-15 min, filled it up with the required amount of coolant/water mixture and drove it around. It was doing ok for a while, but then it started heating up again. This time, the needle didn't shoot all the way up, but still about 3/4 of the way.

I'm guessing and/or hoping that the new thermostat I got is faulty. I'm going to run it w/o the thermostat to see if that is the problem. I know it's not a great idea, but it'll narrow my problems down.

What do you guys think?

Gadget

Good point.. Physically test the temp of the upper/lower rad hose.. If no coolant is making its way to the rad, it'll never get cool.. The heater will never have anything to do with your car overheating unless it's leaking all your coolant out..
check the intake to thermostat housing bypass hose, make sure it's getting hot!! that's the hose that heats the back side of the thermostat and makes it open.. Make sure the spring side of the thermostat is facing the engine, not the hose..

other than that, if everything checks out, remove the thermostat all togother.. if it still overheats, buy a radiator..

I3ooS710

Found out a few things.

I just want to let everyone know that I only bypassed the heater valve because I noticed a small amount of coolant leaking from it so I wanted to bypass it completely.

Here's what I just did..

removed the thermostat, re-bled the system, drove it around. I noticed that it was stead for a while, but started climbing up slowly. Again, the lower hose is still pretty cold. It goes up about 3/4 of the way and stood there. It didn't raise or drop.

With that being said, I've come to the conclusion that my radiator needs to be changed. I don't know what else can possibly be the problem besides the radiator.

I want to thank everyone for their help, but if you have any other inputs, please feel free to let me know.

I guess it's time for an upgrade.

kaoss_11

on my h series it was the radiator, i just broke down and bought a aluminum radiator there was a h-t special. I changed the thermo, my caps, my fan everything you can think of but once I changed the radiator it has never over heated once...

cdizzle

its definately not your radiator it is your headgasket, it has a small leak your not getting any flow to your radiator because the whole cooling system always has air in it cause of the leak, i know u said u changed it 3k miles ago, but who did it? and did u change it because u blew HG alreadY? or jus for maintenance, if u had overheating problems before your cyclinder head could be warped and not creating a good seal between the cylinder head, headgasket and the engine block.

I3ooS710

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cdizzle &raquo;</TD></TR><TR><TD CLASS="quote">its definately not your radiator it is your headgasket, it has a small leak your not getting any flow to your radiator because the whole cooling system always has air in it cause of the leak, i know u said u changed it 3k miles ago, but who did it? and did u change it because u blew HG alreadY? or jus for maintenance, if u had overheating problems before your cyclinder head could be warped and not creating a good seal between the cylinder head, headgasket and the engine block.</TD></TR></TABLE>

I changed my block out a few months ago due to a broken ringland. Since I've changed it, the motor has been running absolutely perfect.

Then I stopped driving it for a couple of months because I was waiting for some parts to come in that I ordered. After I got everything together, that's when I started driving it again.

I'm SURE it's not the headgasket or else I'd see more signs saying so. My coolant resevoir IS NOT overflowing, nor am I getting any white smoke or coolant scents so I'm pretty sure it's not the headgasket.

I've never had overheating problems before until yesterday, therefore, I believe it is the radiator causing this problem.

As I stated early, I had already changed the thermostat, bled the coolant, and checked for any leaks. Even then, it was heating up but not as worse as it was before when it would actually nearly reach the "HOT" area. It stays steady at 3/4 of the way up.

silver bulit

had a similar problem on a trip motor got hot a little low on water thought nothing of it refilled it and had no problems for a year then it started to overheat it would pressurize the cooling system and push all of the coolant out of the system. a few months later took and replaced the rad. good again but pressure would still build periodically. sooner or later you will have sludge build up in your rad. it is most likley the head gasket. i recently replaced the motor and didnt replace the rad oooops! almost overheated a new motor. new rad does wonders for cooling systems that arent plugged. i took apart the old rad to see how bad it was and holy sss it was 95% plugged so change rad redo the head or just buy a 30000 mile motor and slap it in

erasable180

i think its your water pump. no real leaks, no heat, new thermostat. the coolant just isnt circulating. had this happen on a different car, but same symptoms.

Gadget

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by aallbbeerrtttttt &raquo;</TD></TR><TR><TD CLASS="quote">
i think its your water pump. no real leaks, no heat, new thermostat. the coolant just isnt circulating. had this happen on a different car, but same symptoms. </TD></TR></TABLE>

A waterpump in automotive use will never fail in the form of failing to pump unless the "Turbine" physically becomes damaged or by some act of god manages to un-press itself from the input shaft.. which has odds of 1 in 1,000,000,000..

water pumps will fail one of 4 ways..
-Bearing failure (which causes pump lockup)
-Bearing failure (which causes pump shaft slop, and prevents internal seals from correctly sealing which results in a leak)
-Seal failure (leak)
-Physically becomming damaged (From accident, incorrectly installed, or foriegn matter in cooling system IE: bolts/nuts in the cooling system etc.. being ran through the pump during operation)

The funny part is only 2 kinds of failure will make the pump fail completely as a pump.. 1) being physically damaged from accident or 2) bearing failure which causes lockup in which case his engine wouldn't run because it'd rip the timing belt right out of it..

I'd vote to say the radiator is plugged if a blown head gasket or cracked head is ruled out by means of a leak down test..

I3ooS710

I'm praying to God that it is the radiator.

Sitting at a still idle, the motor would idle fine and the temperature level would be normal. about 3 min into a drive, that's when the needle would SLOWLY make it's way up until it hits about 3/4 way and it would hold there. Even if I parked it and let it sit, the temperature won't go down..

I3ooS710

Could any of you guys tell me some symptoms of a bad radiator? I'm getting mixed signals about everything..

Gadget

Just a thought..

Remove your radiator cap.. look at the flat tubes that coolant flow through.. (You might have to drain a little coolant to see them...) If the tops are crusty looking, it's more than possible it's plugged and needs to be replaced..

Check this link out..
http://www.radiatorbarn.com/fa...g.asp

I3ooS710

Thanks! I'll look into it when I get home thanks for the help!