Overheating and i replaced everything.

[conozo]

For the past few months my car has overheated 4 times. I have replaced the thermostat each time. But i noticed that it has only failed when the car has not been moving. So that means to me my fans arent working. So i just replaced the thermosensor on the bottom of the radiator. But the coolant still is having trouble flowing through the engine. I dont have any leaks either. 88 DX Carb

Symptoms

Radiator hose to top of radiator is hot
Radiator hose from bottom of radiator COLD
when i turn off the engine with the cap off, half of the coolant will overflow out of the radiator cap. Its never used to do this before the overheating problems
Overheats when car is not moving, but not all the time


Things i have replaced

Engine was rebuild recently (maybe)(a long story)
Thermostat replaced (even had a failsafe one fail within 1 week)
Waterpump only has 10,000 miles on it
Thermosensor on bottom of radiator (this is the last item i have replaced)
All hoses
Coolant has been replaced several times due to replacing the thermostat several times
Radiator was replaced (10,000 miles on it)


Things i have tested

The fan relay does work, i jumped the two wires and the fans turn on
I grounded the sensor that displays the temperature on your guage cluser, and it is working properly

[marklj]

Have you bled the air from the cooling system?

[nswst8]

Have you changed the radiator cap.

Run a bybass hose to isolate the heater core. To rule out a clogged heater core.

Pull the radiator, flush it to ensure flow.

Use a failsafe thermostat. Pull the thermostat and run the engine w/o the thermostat. Its a last resort.

I once had a car where I replaced the heater hoses, heater stopped working, turned out that one of the heater hoses had a piece of wood that clogged it. Don't ask me how it got in there. Just make sure you check all hoses before putting o the vehicles.

[G. White]

+1 on the hoses
My buddy had a similar problem and one of the radiator hoses ended up being collapsed on the inside. I looked perfect from the outside so there was really no way of visually knowing. Once the motor got a little warm the inside of the hose got lazy and flapped over restricting coolant flow.
Damn strangest thing I've ever seen. Hope this helps.

[greentee76]

Sounds like what mine was doing when I first got it. Check your fuses. There is one in the engine fuse box and one in the fuse box under the dash. The one under the dash was blown on mine and someone replaced it with the wrong amperage. If I jumpered the sensor at the bottom of the radiator the fans would kick on, but wouldn't by themselves.

[conozo]

ok, i will bypass the heater core, check all the hoses, flush the radiator to see if there is a blockage and i have already checked the fuses

Just so you know i am trying to bleed the air from the system, but cant because it seems to not want to circulate now.

I will let you know the results tomorrow.

[nswst8]

Only an Honda OEM thermostat will bleed the air out.

[88Accord-DX]

Only an Honda OEM thermostat will bleed the air out.
There is a way around that, you drill 1/8 hole in the thin metal between the spring & outside edge. You then mount the hole facing north with you install the t-stat.

[Pico]

There is a way around that, you drill 1/8 hole in the thin metal between the spring & outside edge. You then mount the hole facing north with you install the t-stat.

I've done that before and all worked out well

[nswst8]

I forgot to add that little piece of info, Thanks guys.

[conozo]

by north do you mean up, or towards the passenger compartment

[Pico]

by north do you mean up, or towards the passenger compartment

hole at the top position

[conozo]

The other thermostats i purchased from every auto store already has a hole there.

[conozo]

So yesterday i checked everything. I found that the thermostat is working properly, there arent any blockages in the engine, heater core, radiator, or hoses, all hoses are new and good. I filled it up with fluid and ran the car for about an hour trying to get all the air out. The car did not overheat either, infact it felt only warm to the touch. So then i turned the car off, ate dinner, and started it up again, this time i held the throttle at 1500rpm and the enigine heated up quickly and everything seemed hot, such as the hoses, engine, radiator(top and bottom), and the hoses had a lot of pressure in them. The fan still did not turn on and i beleive the hoses felt hard because the coolant was about to boil again, but im not 100% sure on that.

I dont know what else to try, im going to try running it again and see if i can bleed any more air out of it.

[VIPER1988]

is the coolant low each time you check it? my car did the same thing a few weeks ago. found a pinhole in one of the small hoses under the intake mani. replaced and all was good

[nswst8]

What about your water pump, how old is it?

[Dr_Snooz]

If I recall correctly, this is the long story on the rebuilt engine: http://www.3geez.com/forum/showthread.php?t=65639&highlight=lawsuit

I'm not sure how you are verifying the flow of the various cooling components, but from what you describe (the fact that you can't bleed the system and that certain parts of it are overheating, while others are not) there is a restriction. The sad fact is that you have had bozos working on the cooling system and bozos break things very creatively. It's a gift really. You can take the car back to the shop that installed your water pump and tell them to fix it right this time, but then you're back to the whole bozos working on your car problem.

If it were mine, I'd start with a cold engine, remove the rad cap and start it up. When the t-stat opens, you should be able to see the water circulating in the radiator. At some point after that, the cooling fans should turn on. That will give you a good idea of how the system is working overall. When you are done, remove your t-stat and blast a garden hose into the cylinder head. You should get water coming out of the upper hose in torrents. If it trickles out, you'll know there is a restriction. In that case, you start taking stuff apart until you find the restriction. If water rushes out, then you can suspect that something is up with your water pump. If so, you'll need to remove it. As I said, bozos break things creatively. You may find that somebody broke all the fins off the new pump before putting it in. Or you may find that the old, bad pump was WD-40ed to make it quiet and put back in. Or you may find somebody's sneak-a-toke wedged in there or God only knows what else.

Anyway, keep us posted on what you learn.

[conozo]

Coolant is not low. I did blast water through every hose and place where coolant normally goes and it all flowed nicely. My water pump only has 10,000 miles on it, but i guess its the only thing left for me to look at.

When i was working on it yesterday i followed these instructions. http://www.3geez.com/forum/showthread.php?t=66456 I even had coolant flowing out of the bleeder bolt when filling the radiator with the engine off unlike the others had mentioned.

[w261w261]

There is a tester than call tell if you have combustion products in the coolant. I'm wondering if you have a small head gasket leak, which could be pumping up the system in the wrong way, maybe intermittently.

[rfiks]

did u replace the water pump & oil pump???

[Oldblueaccord]

When you say overheating what is it doing? Stock guage or aftermarket. I'm trying to see what your defintion of over heating is.

One thing I would do is remove the T=stat and try running it to see what happens.

Also if you used tap water that has alot of limestone in it it may have clogged the rad already. It only takes maybe 2 years to clog a rad with some water.

wp

[MessyHonda]

there is this pressure tester...you put it where the radiator cap goes and pressure to 15psi and see if your pressure drops

[conozo]

The water pump and oil pump are new with only 10,000 miles on them

When i say overheating the coolant boils, and you can hear it when you turn the car off. Its done that 4 times, but i have noticed it right away and turned the car off. The stock temperature guage shows the temp high also.

The radiator is not clogged, i put the garden hose to it and it flowed out freely, in both directions.

Today i tried to use a block tester to see if i have a blown/leaky head gasket. But i could not use it because everytime i put the tester in the radiator the coolant would rise quickly and coolant would get into the tester. So i stopped, then the coolant started rising and it flowed out of top of the radiator. So i quickly turned off the car, and it flowed out for another 15 seconds. I lost half of my coolant and it wasnt even hot to touch. This is also what it keeps on doing, the over flowing when i turn the car off with the cap off. If the cap is on, everything looks fine.

After that i took off my water pump and it looks new and spins freely.

The next thing i will try is put everything back together and try to run it without the thermostat.

[AccordB20A]

sounds like your having an ass of a time. i reckon it has to be a small head gasket leak. I had the same problem with another engine i had, was only a pinhole leak but was enoguh to make the car overheat after 20 minuites of normal driving

[greentee76]

Maybe I missed it but have you had the radiator cap tested or replaced it?

[Dr_Snooz]

The fan still did not turn on and i beleive the hoses felt hard because the coolant was about to boil again.


i am trying to bleed the air from the system, but cant because it seems to not want to circulate now.

So I'm re-reading this thread and these two things jump out at me.

1. Your fans do not turn on when things get hot. Improperly working fans would sure cause a stopped car to overheat. You could have a bad thermosensor or a bad fan motor (a long shot is your fan blades could be sheared off at the motor, it happened to me), possibly the radiator is bunged and the thermosensor is not getting good coolant flow so isn't signaling properly. Maybe one of our wiring experts could suggest potential components that might need replacing.

2. You can't bleed the system because the coolant isn't flowing. That screams restriction to me. I'll return to the flush. I know that you've checked the flow of various components individually, but have you checked the flow of the entire system after it's all put together with the t-stat out? I would do that.

Finally, it sounds like this is an intermittent thing, so that would suggest an electrical malfunction. I'd take a hard look at the fans and assorted relays, sensors and switches that run them. Also check the resistance on those fans. Make sure they are working well.

Keep us posted.

[MessyHonda]

sometimes the radiator gets clogged...i used a lazer thermometer to see if the radiator has an even distribution of heat...you dont want it to variate more than like 50f in any spot

[conozo]

Heres what i found today.

I put the water pump back on and took the thermostat off. Filled the fluid up and started the car and warmed it up. I followed the same instruction http://www.3geez.com/forum/showthread.php?t=66456 as before still no luck.

Results
-All radiator hoses felt hot
-Radiator was evenly distributing heat from top to bottom and side to side
-When i ran the engine fast the coolant level would drop for a few seconds then would raise/overflow if i kept the engine running fast or if i let it idle again.
-First time i turned off the engine there was no overflow after the engine stopped.
-Second time i turned off the engine there was a overflow for several seconds as described before where i would loose half of my coolant.
-It seems that the longer the car is on the worse these problems are, even if its already warmed up mostly.

I really think i have a head gasket leak, but i still cannot test for it since the coolant keeps overflowing. Is there any other way to test for a head gasket leak thats not super expensive.

I have a video of it overflowing when the car is off. Heres the video, you have to download it first since it will lag (28MB) http://honda.conozo.com/pics_3geez/engine stop - overflow.avi

[Hauntd ca3]

do a leak down test.
you7'd get bubbles in the radiator if the gasket has gone between the cylinder and water jacket.
also a good way of find out how the rings etc are sealing after 20 years of use

[conozo]

do a leak down test.
you7'd get bubbles in the radiator if the gasket has gone between the cylinder and water jacket.
also a good way of find out how the rings etc are sealing after 20 years of use

i didnt know there was a leak down test, but i did some research and it looks like i can really see the health of my engine along with a compression test. So i will do a compression test first then a leak down test.

Hopefully i can prove that my engine sucks, so that i can have a few words with the shop who just "rebuilt" my engine

[88Accord-DX]

On a couple engines with a small anti-freeze leak through the head gasket, I was able to pull the spark plugs out & shine a small flashlight down into the combustion chamber & see the leak. Also, after you pull the spark plug you might be able to see that the plug is wet. You may also smell the anti-freeze on the one that leaks.
A leak down test works good too, make sure the cylinder your testing is at it's TDC point with all valves closed. Leak testers aren't cheap depending on the quality.
Compression test is ok on finding a coolant leak, just harder to detect on real small minuscule leaks.

[w261w261]

More to my post (#19). I had a small head gasket leak in an '85 Volvo, which pumped up the system in the same way you describe. Since I had nothing to lose, I bought a can of Moroso, which worked exactly as promised. Be advised that to use it, you have to flush (REALLY FLUSH) the cooling system, as the presence of anti-freeze will not allow the product to work. It's a lot better than getting into a whole disassembly process, IMO. Last I heard, the Volvo is still sailing along.

Moroso is a well-used, respected product. Look at the company behind it.

http://moroso.com/catalog/categorydisplay.asp?catcode=22005

[Oldblueaccord]

If they claim its rebuilt I wonder if they used the wrong head gasket or it slipped a little and is blocking the coolant ports. Also using straight water will cause coolant ports to bridge over. I had a port on my 318 block that was completly bridged over. I had to use a hammer and a punch to knock the slug out.

I think you have done all you can with it. Maybe force the fans on 100% of the time by pulling the ac fuse and running the ac on fan speed one or hot wiring them to see if you can use it without over heating it.


wp

[Dr_Snooz]

I have a video of it overflowing when the car is off. Heres the video, you have to download it first since it will lag (28MB) http://honda.conozo.com/pics_3geez/engine stop - overflow.avi

That surge looks like backflow from a blockage, once the water pump stops pushing against it.

Sorry. Don't mean to beat a dead horse.



Edit: Forget it. Do the head gasket. At least when you replace it, you'll pull off enough stuff to find your blockage.

...I hope. :nervous:

[conozo]

Still havent figured out exactly what is going on with it. But i am pretty sure its the head gasket (i dont know what else it could possibly be). I fired it up a couple weeks ago and drove it around for a minute or two just because i HAD to drive it. Don't worry, i didnt overheat it.

I haven't started it up in a few months and when i cranked it, it started right away. Took me by surprise since its carbed, old fuel, sitting for months, and was just cold outside.

I'm still debating on fixing it myself (scares me) or having the shop fix it since its under warranty, but then i risk the chance of them screwing something else up.

[Pico]

do the work yourself, if your a little mechanically inclined you should have no problems.
Just dont get cheap on the parts you need.
Did you ever do the leak down test?
I know how frustrating it is to pin point the overheating problem. Im going thru the same problem with my Legend and cannot find the reason why.

[conozo]

Couldn't do the leakdown test, cost too much to purchase and no place rents them, or even knows what they are.

[Hauntd ca3]

if its under warranty, make them check it out.
at least do a comp and leak down to rule out or diagnose a head gasket.
And you do run 50/50 antifreeze to water coolant mix?
running straight water will cause boiling and over heating way earlier than 50/50 mix.
also whip the rad out and take it to a rad specialist and det it flushed and pressure tested.
should only cost 30 or 40 dollars and they'll do a far better job than you ever could at home

[xxxfrankensteinxxx]

so do your fans turn on when you said you can hear it boiling?

[conozo]

So i finally had the shop look at it. I didn't want to since they screwed up everything else. They did fix it, the problem was so stupid and they were so stupid for what they did. The problem was that the main radiator hoses were switched. Thats what was causing the fan not to come one since it was cooled down by the time it got to the thermosensor.

I know i did take off everything to look at it after it overheated a couple times, but i put it back the way they did, not thinking that they would have put the hoses on wrong. I just cant believe that it was like this for so long without any major problems especially since i drove from indiana to arizona and up pikes peak then another 5000 miles after that trip before i finally stopped driving it because of the problems. I never let it overheat that much, the compression test showed that it did not damage the engine. All numbers were dead on 180psi.

Im done with this shop and any shop for that matter. This is probably the 20th thing they did wrong on this particular car. Im always going to do the work myself now no matter what it is.

[russiankid]

So they put the lower radiator hose onto the upper hose spigot and the upper onto the lower spigot? That would send hot coolant to the bottom of the radiator so then the thermosensor had to have turned the fans on....

[conozo]

So they put the lower radiator hose onto the upper hose spigot and the upper onto the lower spigot? That would send hot coolant to the bottom of the radiator so then the thermosensor had to have turned the fans on....

Yes they switched the spigots on the engine side. Im looking at the shop manual right now and it was definitely hooked up backwards. Now that it is connected right, the engine warms up faster and the fans actually come on now. Also before the thermostat would take forever to open, i believe thats why the fan wasn't coming on too. Im not exactly sure how it works so much different this way, but the evidence shows that the radiator hoses cannot be switched around for normal operation.

[russiankid]

I don't see how that would affect the thermostat. It would still open but send hot coolant to the bottom of the radiator.

[87roach]

How can you screw that up? Wow... I didn't think they were long enough to switch up. Glad to hear you sorted it out and that it was something stupidly simple!

[russiankid]

The lower rad hose on the engine is right under the upper.

[conozo]

I don't see how that would affect the thermostat. It would still open but send hot coolant to the bottom of the radiator.

I think what was happening was that it was sucking a lot of air into the system. That may explain why i could not bleed the system and the "boil over" effect when i turned the car off with the cap off.

I really feel dumb not noticing this. Tell me, am i dumb for not noticing this for so long.

[russiankid]

Well its quite obvious to notice when the upper radiator hose tucks under the head instead of running next to it like it should.

[Dr_Snooz]

Im done with this shop and any shop for that matter. This is probably the 20th thing they did wrong on this particular car. Im always going to do the work myself now no matter what it is.

If that is the only thing you learned from this, then you've learned enough. If you care and aren't strung out, you are already miles ahead of most every shop. I'm glad it was a simple fix.

[MessyHonda]

wow...that sucks...good thing you figured it out....if the hoses looked like they fit it should of been cool

[conozo]

I thought i would give a little update. The hoses being connected backwards was definitely the problem. I have been driving it a lot in stop and go traffic, let it idle when hot out for a while and its never even began to overheat. The temp gauge sits just a hair below half way like it always was before this problem.